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2016 Volume 44 Issue 11
2016, 44(11): 1633-1638
doi: 10.11895/j.issn.0253-3820.160535
Abstract:
Salbutamol and Clenbuterol are often used as β-agonists and illegally added in pig feed, resulting in pork contaminated and even leading athletes excessive excitability. Therefore, it has great significance for establishing a new rapid detection method of salbutamol and clenbuterol in pork. In this study, internal extraction electrospray ionization-mass spectrometry (iEESI-MS) technology was used for directly qualitative and quantitative analysis of salbutamol and clenbuterol in pork tissues without sample pretreatment. The results showed that this method had a high sensitivity to salbutamol and clenbuterol analysis with detection limits of (LOD) 6.2 and 9.8 ng/kg, respectively, while the analysis time for detecting single sample and single index was less than 30 s. In a concentration range of 0.01-1000 μg/kg, the logarithm of signal intensity (Y) and the logarithm of concentration (X) have a good linear relationship. This method has many advantages such as rapid analysis, low sample consumption and high sensitivity, which is ideal for rapid detection of trace salbutamol and clenbuterol.
Salbutamol and Clenbuterol are often used as β-agonists and illegally added in pig feed, resulting in pork contaminated and even leading athletes excessive excitability. Therefore, it has great significance for establishing a new rapid detection method of salbutamol and clenbuterol in pork. In this study, internal extraction electrospray ionization-mass spectrometry (iEESI-MS) technology was used for directly qualitative and quantitative analysis of salbutamol and clenbuterol in pork tissues without sample pretreatment. The results showed that this method had a high sensitivity to salbutamol and clenbuterol analysis with detection limits of (LOD) 6.2 and 9.8 ng/kg, respectively, while the analysis time for detecting single sample and single index was less than 30 s. In a concentration range of 0.01-1000 μg/kg, the logarithm of signal intensity (Y) and the logarithm of concentration (X) have a good linear relationship. This method has many advantages such as rapid analysis, low sample consumption and high sensitivity, which is ideal for rapid detection of trace salbutamol and clenbuterol.
2016, 44(11): 1639-1645
doi: 10.11895/j.issn.0253-3820.160509
Abstract:
Gas shale is one of the important unconventional hydrocarbon source rocks, whose composition, such as mineral components and trace elements, has been proven as important geochemical proxies playing essential roles in indicating the gas potential and gas productivity in recent geological researches. Fast and accurate measurements of the shale composition will reveal rich information for understanding and evaluation of gas shale reservoirs. In this paper, we demonstrated the potentiality as well as feasibility of laser-induced breakdown spectroscopy (LIBS) as an effective technique to perform spectrochemical analysis for shale samples. For this experiment, a Nd:YAG laser at the fundamental wavelength of 1064 nm provided pulses for the shale materials. An echelle spectrometer equipped with an ICCD camera was employed to disperse and record the spectra. Meanwhile, five shale samples were collected at different depth from 2396 m to 3428 m. The LIBS device was used to obtain the spectrum, and combined with the principal component score of each spectrum to draw a two-dimensional diagram. The obtained results revealed that more than 350 lines emitted by 22 different elements were found. Among these species, major elements like Si, Al, Fe, Ca, Mg, K and Na, and redox sensitive trace elements such as Cu, Cr, Ni, Sr, and Ni were detected with high signal-to-noise ratio. In principal component scores diagram, different types of carbonaceous shale were obviously separated, and the results were consistent with the spectra classification. The observed results also show that laser-induced breakdown spectroscopy combined with principal component analysis (PCA) method can be used for carbonaceous shale discriminant field in the future, providing scientific data and means to improve classification performance and enhance the exploitation and evaluation of gas shale reservoirs.
Gas shale is one of the important unconventional hydrocarbon source rocks, whose composition, such as mineral components and trace elements, has been proven as important geochemical proxies playing essential roles in indicating the gas potential and gas productivity in recent geological researches. Fast and accurate measurements of the shale composition will reveal rich information for understanding and evaluation of gas shale reservoirs. In this paper, we demonstrated the potentiality as well as feasibility of laser-induced breakdown spectroscopy (LIBS) as an effective technique to perform spectrochemical analysis for shale samples. For this experiment, a Nd:YAG laser at the fundamental wavelength of 1064 nm provided pulses for the shale materials. An echelle spectrometer equipped with an ICCD camera was employed to disperse and record the spectra. Meanwhile, five shale samples were collected at different depth from 2396 m to 3428 m. The LIBS device was used to obtain the spectrum, and combined with the principal component score of each spectrum to draw a two-dimensional diagram. The obtained results revealed that more than 350 lines emitted by 22 different elements were found. Among these species, major elements like Si, Al, Fe, Ca, Mg, K and Na, and redox sensitive trace elements such as Cu, Cr, Ni, Sr, and Ni were detected with high signal-to-noise ratio. In principal component scores diagram, different types of carbonaceous shale were obviously separated, and the results were consistent with the spectra classification. The observed results also show that laser-induced breakdown spectroscopy combined with principal component analysis (PCA) method can be used for carbonaceous shale discriminant field in the future, providing scientific data and means to improve classification performance and enhance the exploitation and evaluation of gas shale reservoirs.
2016, 44(11): 1646-1651
doi: 10.11895/j.issn.0253-3820.160109
Abstract:
Trace elements play a very important role in biological organism and closely related to many diseases. The new analytical methods are urgently needed for in-situ determination of trace elements in biological tissues or single cells. A method based on laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was developed for such in-situ analysis. Line ablation mode was chosen and the output energy of the laser was also optimized at a low fluence of less than 1 J/cm2. The two kinds of elemental bio imaging of both a coronal section from mouse brain and single cells exposed to gold nanoparticles were obtained by the developed method. Because of the unique characteristics, such as good spatial resolution, excellent detection limit, and reasonable running cost, LA-ICP-MS will be applied widely and become a useful tool in biomedical research in the future.
Trace elements play a very important role in biological organism and closely related to many diseases. The new analytical methods are urgently needed for in-situ determination of trace elements in biological tissues or single cells. A method based on laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was developed for such in-situ analysis. Line ablation mode was chosen and the output energy of the laser was also optimized at a low fluence of less than 1 J/cm2. The two kinds of elemental bio imaging of both a coronal section from mouse brain and single cells exposed to gold nanoparticles were obtained by the developed method. Because of the unique characteristics, such as good spatial resolution, excellent detection limit, and reasonable running cost, LA-ICP-MS will be applied widely and become a useful tool in biomedical research in the future.
2016, 44(11): 1652-1658
doi: 10.11895/j.issn.0253-3820.160338
Abstract:
An ultra performance liquid chromatography-tandem mass (UPLC-MS/MS) spectrometry method was established for determination of the contents of bioamine and amino acid neurochemicals in hippocampus and cerebral cortex of rat. Hypercarb column (100 mm×2.1 mm, 5 μm) was used for the sample separation with 0.1% formic acid-methanol as the mobile phase under gradient elution. The neurochemicals were detected by MS/MS using ESI ion source under positive ionization mode with MRM scan. Both quantification and confirmation ions were chosen for each 6 bioamine and 11 amino acid neurochemicals. The influence of two different processing methods on the contents of neurochemicals in brain tissues was compared. Total 17 neurochemicals were simultaneously detected in 10 min. The calibration curve was with a good linear relationship. The intra-day and inter-day precision, average recovery and repeatability could meet the analysis requirement. This UPLC-MS/MS method shows excellent selectivity, accuracy, high sensitivity, specificity and good repeatability, and is suitable for the separation and quantization of bioamine and amino acid neurochemicals in brain tissue.
An ultra performance liquid chromatography-tandem mass (UPLC-MS/MS) spectrometry method was established for determination of the contents of bioamine and amino acid neurochemicals in hippocampus and cerebral cortex of rat. Hypercarb column (100 mm×2.1 mm, 5 μm) was used for the sample separation with 0.1% formic acid-methanol as the mobile phase under gradient elution. The neurochemicals were detected by MS/MS using ESI ion source under positive ionization mode with MRM scan. Both quantification and confirmation ions were chosen for each 6 bioamine and 11 amino acid neurochemicals. The influence of two different processing methods on the contents of neurochemicals in brain tissues was compared. Total 17 neurochemicals were simultaneously detected in 10 min. The calibration curve was with a good linear relationship. The intra-day and inter-day precision, average recovery and repeatability could meet the analysis requirement. This UPLC-MS/MS method shows excellent selectivity, accuracy, high sensitivity, specificity and good repeatability, and is suitable for the separation and quantization of bioamine and amino acid neurochemicals in brain tissue.
2016, 44(11): 1659-1664
doi: 10.11895/j.issn.0253-3820.160516
Abstract:
A method of capillary electrophoresis (CE) combined with inductively coupled plasma-mass spectrometry (ICP-MS) was established for the determination of lead ion (Pb), trimethyl lead (TML) and triethyl lead (TEL). Meanwhile, the extraction technology of different species of lead in algae was established and optimized for the qualitative and quantitative analysis. The results showed that three kinds of lead compounds could be effectively separated within 20 min by CE-ICP-MS with 70 mmol/L H3BO3-17.5 mmol/L Na2B4O7 (pH 8.90) as a buffer solution. There was a good reproducibility of migration time (RSD<4%) and peak area (RSD<5%). Three kinds of lead compounds had good linear relationship within 10-200 μg/L with the correlation coefficient larger than 0.90. The detection limits of Pb, TML and TEL (S/N=3, Pb) were 0.091, 0.023 and 0.030 μg/L, respectively. The extraction rate of Pb reached more than 80% by using fractional extraction, and the recovery rates of Pb, TML and TEL were 103.6%, 95.7% and 90.6%, respectively, with algae as the substrate. The lead content detection of laver and kelp showed that Pb in algae mainly existed in the form of Pb. The method had the advantages of siplicity, high efficiency and low sample consumption, which could provide technical support for the quality control of marine algae and other marine products.
A method of capillary electrophoresis (CE) combined with inductively coupled plasma-mass spectrometry (ICP-MS) was established for the determination of lead ion (Pb), trimethyl lead (TML) and triethyl lead (TEL). Meanwhile, the extraction technology of different species of lead in algae was established and optimized for the qualitative and quantitative analysis. The results showed that three kinds of lead compounds could be effectively separated within 20 min by CE-ICP-MS with 70 mmol/L H3BO3-17.5 mmol/L Na2B4O7 (pH 8.90) as a buffer solution. There was a good reproducibility of migration time (RSD<4%) and peak area (RSD<5%). Three kinds of lead compounds had good linear relationship within 10-200 μg/L with the correlation coefficient larger than 0.90. The detection limits of Pb, TML and TEL (S/N=3, Pb) were 0.091, 0.023 and 0.030 μg/L, respectively. The extraction rate of Pb reached more than 80% by using fractional extraction, and the recovery rates of Pb, TML and TEL were 103.6%, 95.7% and 90.6%, respectively, with algae as the substrate. The lead content detection of laver and kelp showed that Pb in algae mainly existed in the form of Pb. The method had the advantages of siplicity, high efficiency and low sample consumption, which could provide technical support for the quality control of marine algae and other marine products.
2016, 44(11): 1665-1670
doi: 10.11895/j.issn.0253-3820.160580
Abstract:
A method of in situ multi-elements 2D imaging on single pyrite was developed using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Nine elements and nearly 50 thousands valid data were acquired in a 1 mm×1 mm scanning area, with the total analyzed time of 1.5 h. The data showed that, the signals of Fe and S were uniformly distributed on the pyrite, and the ratio data of Fe/S was centralized with a lower relative standard deviation of 11.6%, indicating the good homogeneity of this pyrite and stability of this method. Compared to the surrounding black shale, the detected trace elements on the pyrite showed different degrees of enrichment or loss, which might be the response of redox environment during this pyrite forming or the later secondary reforming process. The method will help for the popularization and application of LA-ICP-MS in single mineral particles analysis, and provide more direct and accurate visual data for the study of paleoenvironment, source rock and fluid accumulation.
A method of in situ multi-elements 2D imaging on single pyrite was developed using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Nine elements and nearly 50 thousands valid data were acquired in a 1 mm×1 mm scanning area, with the total analyzed time of 1.5 h. The data showed that, the signals of Fe and S were uniformly distributed on the pyrite, and the ratio data of Fe/S was centralized with a lower relative standard deviation of 11.6%, indicating the good homogeneity of this pyrite and stability of this method. Compared to the surrounding black shale, the detected trace elements on the pyrite showed different degrees of enrichment or loss, which might be the response of redox environment during this pyrite forming or the later secondary reforming process. The method will help for the popularization and application of LA-ICP-MS in single mineral particles analysis, and provide more direct and accurate visual data for the study of paleoenvironment, source rock and fluid accumulation.
2016, 44(11): 1671-1678
doi: 10.11895/j.issn.0253-3820.160298
Abstract:
Hexamethylene triperoxide diamine (HMTD), as one kind of new organic peroxide explosives, was often used in the terrorist attacks due to its easy synthesis from available starting materials. Herein, on the basis of nonradioactive ionization source vacuum ultraviolet lamp (VUV), a dopant-assisted positive photoionization ion mobility spectrometer was developed for the determination of HMTD. Toluene and ketones such as acetone, and 2-butanone, were tested as dopants, and acetone was finally chosen as the optimal dopant for the quantitative detection of HMTD in perfume. With mass spectrometer, the reactant ions and the product ions of HMTD were assigned. The reactant ions of acetone were proton dimer m/z 117[(CH3)2CO]2H+, while the product ions of HMTD were proton molecular ion m/z 209[HMTD+H]+. When both the drift tube and the thermal desorber temperature was under 120℃, the HMTD standard samples were quantified with the maximum signal intensity and the signal intensity at the 10th second, the linear range was 5-50 ng/μL and 5-100 ng/μL, and the limit of detection (LOD) was 0.2 and 0.3 ng/μL, respectively. Cosmetics such as perfume often interfered and inhibited the measurement of ion mobility spectrometry, so the detection of HMTD in perfume matrix for the rapid screening and detection of HMTD on-site was of realistic significance. These two quantitative methods were used for the quantitative detection of HMTD in three different brands of perfume samples. By comparison, the method using the 10th second signal intensity of HMTD for the quantitative detection had a better recovery and accuracy. This method was suitable for the accurate and rapid quantitative detection of HMTD in complex matrix.
Hexamethylene triperoxide diamine (HMTD), as one kind of new organic peroxide explosives, was often used in the terrorist attacks due to its easy synthesis from available starting materials. Herein, on the basis of nonradioactive ionization source vacuum ultraviolet lamp (VUV), a dopant-assisted positive photoionization ion mobility spectrometer was developed for the determination of HMTD. Toluene and ketones such as acetone, and 2-butanone, were tested as dopants, and acetone was finally chosen as the optimal dopant for the quantitative detection of HMTD in perfume. With mass spectrometer, the reactant ions and the product ions of HMTD were assigned. The reactant ions of acetone were proton dimer m/z 117[(CH3)2CO]2H+, while the product ions of HMTD were proton molecular ion m/z 209[HMTD+H]+. When both the drift tube and the thermal desorber temperature was under 120℃, the HMTD standard samples were quantified with the maximum signal intensity and the signal intensity at the 10th second, the linear range was 5-50 ng/μL and 5-100 ng/μL, and the limit of detection (LOD) was 0.2 and 0.3 ng/μL, respectively. Cosmetics such as perfume often interfered and inhibited the measurement of ion mobility spectrometry, so the detection of HMTD in perfume matrix for the rapid screening and detection of HMTD on-site was of realistic significance. These two quantitative methods were used for the quantitative detection of HMTD in three different brands of perfume samples. By comparison, the method using the 10th second signal intensity of HMTD for the quantitative detection had a better recovery and accuracy. This method was suitable for the accurate and rapid quantitative detection of HMTD in complex matrix.
2016, 44(11): 1679-1685
doi: 10.11895/j.issn.0253-3820.160469
Abstract:
A novel on-site rapid detection method for ammonia detection in water was developed by using ultraviolet photoionization high field-asymmetric waveform ion mobility spectrometry (UV-FAIMS). The position of ammonia characteristic ion peak was acquired by the comparison between the characteristic compensation voltage (CV) in standard ammonia sample and trace amount ammonia in water. The relation between the positions of ammonia characteristic ion peaks under different dispersion voltages (DV) was studied. The values of α2, α4 were 2.21×10-5 Td-2 and -1.45323×10-9 Td-4, respectively. The different concentrations of ammonia in water was measured with a limit of detection (LOD) of 9.2 μg/L (S/N=3). This study provided a rapid, non-pretreatment means for the detection of ammonia in water matrices.
A novel on-site rapid detection method for ammonia detection in water was developed by using ultraviolet photoionization high field-asymmetric waveform ion mobility spectrometry (UV-FAIMS). The position of ammonia characteristic ion peak was acquired by the comparison between the characteristic compensation voltage (CV) in standard ammonia sample and trace amount ammonia in water. The relation between the positions of ammonia characteristic ion peaks under different dispersion voltages (DV) was studied. The values of α2, α4 were 2.21×10-5 Td-2 and -1.45323×10-9 Td-4, respectively. The different concentrations of ammonia in water was measured with a limit of detection (LOD) of 9.2 μg/L (S/N=3). This study provided a rapid, non-pretreatment means for the detection of ammonia in water matrices.
2016, 44(11): 1686-1691
doi: 10.11895/j.issn.0253-3820.160405
Abstract:
The performance of an ion mobility spectrometer (IMS) was influenced by several factors such as drift field strength, gate pulse width, the operational parameters for ion source, dimensions of the drift tube, the machining quality of ion gate and the transmission of aperture grid. The gate pulse width and drift field strength needed to be tuned to balance the selectivity and sensitivity in real applications. This study investigated the influence of drift field strengths and the gate pulse widths on both selectivity and sensitivity of microwave induced plasma ionization ion mobility spectrometry (MIPI-IMS) made by our laboratory. Experimental results showed that there existed a drift field strength that made the resolving power reach the best. Moreover, the drift field strength for the best resolution was different from each other under different gate pulse widths. Increasing the drift field strength and gate pulse width was propitious to improve the sensitivity of MIPI-IMS. In comparison with other ion source with weak ion current, the MIPI source had strong ion current, which enabled the MIPI-IMS work in wider range in drift field strength and gate pulse width in practice. The results were helpful for the improvement of the performance of MIPI-IMS. Finally, 2-propanol was used to test the performance of the MIPI-IMS. The results showed that the limit of detection of MIPI-IMS could reach 7.7×10-11 (V/V) and the resolution was 66.
The performance of an ion mobility spectrometer (IMS) was influenced by several factors such as drift field strength, gate pulse width, the operational parameters for ion source, dimensions of the drift tube, the machining quality of ion gate and the transmission of aperture grid. The gate pulse width and drift field strength needed to be tuned to balance the selectivity and sensitivity in real applications. This study investigated the influence of drift field strengths and the gate pulse widths on both selectivity and sensitivity of microwave induced plasma ionization ion mobility spectrometry (MIPI-IMS) made by our laboratory. Experimental results showed that there existed a drift field strength that made the resolving power reach the best. Moreover, the drift field strength for the best resolution was different from each other under different gate pulse widths. Increasing the drift field strength and gate pulse width was propitious to improve the sensitivity of MIPI-IMS. In comparison with other ion source with weak ion current, the MIPI source had strong ion current, which enabled the MIPI-IMS work in wider range in drift field strength and gate pulse width in practice. The results were helpful for the improvement of the performance of MIPI-IMS. Finally, 2-propanol was used to test the performance of the MIPI-IMS. The results showed that the limit of detection of MIPI-IMS could reach 7.7×10-11 (V/V) and the resolution was 66.
2016, 44(11): 1692-1697
doi: 10.11895/j.issn.0253-3820.160176
Abstract:
By massively analyzing proteins extracted from cells, tissues and organisms using mass spectrometry, proteomics is capable of providing information about change in proteins expression, modification, composition and quantification. However, most immobilized enzymes used in mass spectrometry based "shotgun" proteomic strategy are prepared using solid materials as the immobilization matrix and digest the substrate proteins in heterogeneous system. The inherent mass transfer resistance in the solid-liquid interface and steric hindrance of the solid matrix limits the digestion efficiency and sample processing throughput. Here, we prepared a novel immobilized enzyme using soluble thermo-sensitive polymer as the matrix material by exploiting the thermo-responsive ability of the polymer to environmental temperature changes. The thermo-sensitive immobilized trypsin had the feature of "homogeneous digestion at high temperature and heterogeneous separation at low temperature" and the advantage of significantly shortened digestion time and recover and reuse of the enzyme. An amino acid sequence covering up to 94% in 1-min digestion was obtained, which was higher than that of 74% obtained by in-solution digestion for 12 h. Finally, the immobilized trypsin was successfully applied to fast and highly efficient digestion of complex proteome extracted from HeLa cell. The efficiency of immobilized digestion in 1 min was similar to that of solution digestion in 12 h, which sufficiently demonstrated the application potential of this thermo-sensitive immobilized trypsin in proteomics research.
By massively analyzing proteins extracted from cells, tissues and organisms using mass spectrometry, proteomics is capable of providing information about change in proteins expression, modification, composition and quantification. However, most immobilized enzymes used in mass spectrometry based "shotgun" proteomic strategy are prepared using solid materials as the immobilization matrix and digest the substrate proteins in heterogeneous system. The inherent mass transfer resistance in the solid-liquid interface and steric hindrance of the solid matrix limits the digestion efficiency and sample processing throughput. Here, we prepared a novel immobilized enzyme using soluble thermo-sensitive polymer as the matrix material by exploiting the thermo-responsive ability of the polymer to environmental temperature changes. The thermo-sensitive immobilized trypsin had the feature of "homogeneous digestion at high temperature and heterogeneous separation at low temperature" and the advantage of significantly shortened digestion time and recover and reuse of the enzyme. An amino acid sequence covering up to 94% in 1-min digestion was obtained, which was higher than that of 74% obtained by in-solution digestion for 12 h. Finally, the immobilized trypsin was successfully applied to fast and highly efficient digestion of complex proteome extracted from HeLa cell. The efficiency of immobilized digestion in 1 min was similar to that of solution digestion in 12 h, which sufficiently demonstrated the application potential of this thermo-sensitive immobilized trypsin in proteomics research.
2016, 44(11): 1698-1706
doi: 10.11895/j.issn.0253-3820.160354
Abstract:
The diatom Nitzschia closterium f. minutissima was selected as the object to study the 13C labeled extent and speed of photosynthesis lipids by ultra high pressure liquid chromatography coupled with quadrupole orbitrap high resolution mass spectrometry. The results showed that all four types of lipid were labeled clearly by 13C within 10 days in the stationary phase. The total labeled amount by 13C of digalactosyl diacylglycerol (DGDG), phosphatidylglycerol (PG) and sulfoquinovosyl diacylglycerol (SQDG) increased from entering the stationary phase to the eighth day, but declined later. And the total labeled amount of DGDG, PG and SQDG reached the maximum of (173±24) ng/mg, (473±41) ng/mg and (1224±21) ng/mg on the eighth day with the labeled rate of 56.3%, 38.4% and 62.6%, respectively. The total labeled amount by 13C of monogalactosyl diacylglycerol (MGDG) showed a continued upward trend during the 10 days, and reached (956±51) ng/mg on the tenth day, with marked rate of 87.3%. It was suggested that the synthesized time of different lipid was different. Therefore, for studying assimilation mechanism of microalgae lipids by marine organisms, the lipid content that labeled by 13C should reach the maximum. So if for DGDG, PG and SQDG, we should choose the diatom labeled 8 days by 13C to feed the marine organisms. Meanwhile if for MGDG, we should choose the diatom labeled 10 days by 13C to feed the marine organisms.
The diatom Nitzschia closterium f. minutissima was selected as the object to study the 13C labeled extent and speed of photosynthesis lipids by ultra high pressure liquid chromatography coupled with quadrupole orbitrap high resolution mass spectrometry. The results showed that all four types of lipid were labeled clearly by 13C within 10 days in the stationary phase. The total labeled amount by 13C of digalactosyl diacylglycerol (DGDG), phosphatidylglycerol (PG) and sulfoquinovosyl diacylglycerol (SQDG) increased from entering the stationary phase to the eighth day, but declined later. And the total labeled amount of DGDG, PG and SQDG reached the maximum of (173±24) ng/mg, (473±41) ng/mg and (1224±21) ng/mg on the eighth day with the labeled rate of 56.3%, 38.4% and 62.6%, respectively. The total labeled amount by 13C of monogalactosyl diacylglycerol (MGDG) showed a continued upward trend during the 10 days, and reached (956±51) ng/mg on the tenth day, with marked rate of 87.3%. It was suggested that the synthesized time of different lipid was different. Therefore, for studying assimilation mechanism of microalgae lipids by marine organisms, the lipid content that labeled by 13C should reach the maximum. So if for DGDG, PG and SQDG, we should choose the diatom labeled 8 days by 13C to feed the marine organisms. Meanwhile if for MGDG, we should choose the diatom labeled 10 days by 13C to feed the marine organisms.
2016, 44(11): 1707-1714
doi: 10.11895/j.issn.0253-3820.160323
Abstract:
Two-dimensional axisymmetric simulations of electrospray ion source were built by Fluent software. The gas flow distribution was evaluated under comparable conditions, including configurations of ion source, ways to pump auxiliary gas and gas flow rates. The simulation results suggested that, rectangular ion source produced more stable flow distribution than other ion sources. Despite liquid flow was focused by both coaxial gas and orthogonal gas, the two pump ways had different effects on gas flow distribution. With the flow rate of coaxial gas increasing, backmixing region near the nozzle was enlarged and the stagnation point was changed, while the size of backmixing region was almost invariably with flow rate of orthogonal gas. The experimental validation was performed using Turbo V. The influences of spray needle position and gas flow rate on the detection of total ion current (TIC) were investigated. The experimental results agreed well with numerical simulation results.
Two-dimensional axisymmetric simulations of electrospray ion source were built by Fluent software. The gas flow distribution was evaluated under comparable conditions, including configurations of ion source, ways to pump auxiliary gas and gas flow rates. The simulation results suggested that, rectangular ion source produced more stable flow distribution than other ion sources. Despite liquid flow was focused by both coaxial gas and orthogonal gas, the two pump ways had different effects on gas flow distribution. With the flow rate of coaxial gas increasing, backmixing region near the nozzle was enlarged and the stagnation point was changed, while the size of backmixing region was almost invariably with flow rate of orthogonal gas. The experimental validation was performed using Turbo V. The influences of spray needle position and gas flow rate on the detection of total ion current (TIC) were investigated. The experimental results agreed well with numerical simulation results.
2016, 44(11): 1715-1720
doi: 10.11895/j.issn.0253-3820.160167
Abstract:
Four kinds of thioarsenates, HnAsSO3n-3, HnAsS2O2n-3, HnAsS3On-3 and HnAsS4n-3, were synthesized and identified by electrospray ionization-high resolution mass spectrometry (ESI-HR-MS). With the synthetic thioarsenates as standards, a quantitative analytical method based on ion chromatograph-inductively coupled plasma mass spectrometry (IC-ICP-MS) was set up to simultaneously determine the concentrations of arsenite, arsenate, mono-thioarsenate, di-thioarsenate, tri-thioarsenate, and tetra-thioarsenate in water. The linear range of the method was from 3.3 μg/L to 833 μg/L with the correlation coefficients higher than 0.99, and the detection limits were between 0.4 μg/L and 25 μg/L. The synthetic standard materials of thioarsenates and the quantitative analysis method established in this study are of great significance for future investigations on the environmental transportation and transformation of various arsenic species derived from natural sulfidic waters.
Four kinds of thioarsenates, HnAsSO3n-3, HnAsS2O2n-3, HnAsS3On-3 and HnAsS4n-3, were synthesized and identified by electrospray ionization-high resolution mass spectrometry (ESI-HR-MS). With the synthetic thioarsenates as standards, a quantitative analytical method based on ion chromatograph-inductively coupled plasma mass spectrometry (IC-ICP-MS) was set up to simultaneously determine the concentrations of arsenite, arsenate, mono-thioarsenate, di-thioarsenate, tri-thioarsenate, and tetra-thioarsenate in water. The linear range of the method was from 3.3 μg/L to 833 μg/L with the correlation coefficients higher than 0.99, and the detection limits were between 0.4 μg/L and 25 μg/L. The synthetic standard materials of thioarsenates and the quantitative analysis method established in this study are of great significance for future investigations on the environmental transportation and transformation of various arsenic species derived from natural sulfidic waters.
2016, 44(11): 1721-1727
doi: 10.11895/j.issn.0253-3820.160531
Abstract:
A method for rapid determination of acidithiobacillus ferrooxidans (At.f) metabolites by ambient corona discharge ionization mass spectrometry was established. Three injection modes were applied to study the effects such as headspace sampling, interface sampling and neutral desorption sampling. Under the optimized experimental conditions, the metabolites, such as small molecule esters and amines were detected by ambient corona discharge ionization mass spectrometry and confirmed using tandem mass spectrometry (MS/MS). Further principal component analysis (PCA) and cluster analysis (CA) of the mass spectrometric results allowed a confident discrimination of different bacterial samples. Ambient corona discharge ionization mass spectrometry has the advantages of no sample pretreatment, convenient operation, high sensitivity and high analytical speed, which will be an attractive method to rapidly identification of microorganisms.
A method for rapid determination of acidithiobacillus ferrooxidans (At.f) metabolites by ambient corona discharge ionization mass spectrometry was established. Three injection modes were applied to study the effects such as headspace sampling, interface sampling and neutral desorption sampling. Under the optimized experimental conditions, the metabolites, such as small molecule esters and amines were detected by ambient corona discharge ionization mass spectrometry and confirmed using tandem mass spectrometry (MS/MS). Further principal component analysis (PCA) and cluster analysis (CA) of the mass spectrometric results allowed a confident discrimination of different bacterial samples. Ambient corona discharge ionization mass spectrometry has the advantages of no sample pretreatment, convenient operation, high sensitivity and high analytical speed, which will be an attractive method to rapidly identification of microorganisms.
2016, 44(11): 1728-1734
doi: 10.11895/j.issn.0253-3820.160408
Abstract:
A method was established for the qualitative identification and quantitative determination of DON, 3-Ac-DON, 15-Ac-DON, DOM-1 in cereal and cereal products based on solid phase extraction and ultra performance liquid chromatography-quadrupole linear ion trap mass spectrometry (UPLC-QTRAP-MS/MS) with isotopic dilution. Samples were extracted by the mixture of acetonitrile and water (84:16, V/V), degreased by hexane saturated with acetonitrile and purified by HLB solid phase extraction cartridge. The target analytes were separated by Waters Atlantis® T3 column with gradient elution by mobile phases which consisted of acetonitrile and 0.02% ammonia water. A scheduled multiple reaction monitoring (MRM) in negative mode as survey scan and an enhanced product ion (EPI) scan as dependent scan in an information dependent acquisition (IDA) experiment were adopted in mass spectrometry acquisition. On-line lab-built MS/MS library as well as the isotope internal standards was employed for the identification and qualification. For each analyte, the correlation coefficient was above 0.999 in the linear range of 1-300 μg/L. The limits of detection (LOD) and quantitation (LOQ) were 0.1 μg/kg and 0.3 μg/kg, respectively. The mean recovery was 81.3%-101.7% at three spiked levels of 5, 50, 200 μg/kg. The relative standard deviation (RSD) was no more than 5%. The proposed method was successfully applied to the analysis of FAPAS's QC samples and five representative samples. This method was simple, fast and precise, and suitable for the determination and confirmation of deoxynivalenol and its derivatives and metabolites in cereal and cereal products.
A method was established for the qualitative identification and quantitative determination of DON, 3-Ac-DON, 15-Ac-DON, DOM-1 in cereal and cereal products based on solid phase extraction and ultra performance liquid chromatography-quadrupole linear ion trap mass spectrometry (UPLC-QTRAP-MS/MS) with isotopic dilution. Samples were extracted by the mixture of acetonitrile and water (84:16, V/V), degreased by hexane saturated with acetonitrile and purified by HLB solid phase extraction cartridge. The target analytes were separated by Waters Atlantis® T3 column with gradient elution by mobile phases which consisted of acetonitrile and 0.02% ammonia water. A scheduled multiple reaction monitoring (MRM) in negative mode as survey scan and an enhanced product ion (EPI) scan as dependent scan in an information dependent acquisition (IDA) experiment were adopted in mass spectrometry acquisition. On-line lab-built MS/MS library as well as the isotope internal standards was employed for the identification and qualification. For each analyte, the correlation coefficient was above 0.999 in the linear range of 1-300 μg/L. The limits of detection (LOD) and quantitation (LOQ) were 0.1 μg/kg and 0.3 μg/kg, respectively. The mean recovery was 81.3%-101.7% at three spiked levels of 5, 50, 200 μg/kg. The relative standard deviation (RSD) was no more than 5%. The proposed method was successfully applied to the analysis of FAPAS's QC samples and five representative samples. This method was simple, fast and precise, and suitable for the determination and confirmation of deoxynivalenol and its derivatives and metabolites in cereal and cereal products.
2016, 44(11): 1735-1741
doi: 10.11895/j.issn.0253-3820.160232
Abstract:
The low-polarity constituents from Lepidium meyenii in Yunnan and Peru were detected by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The effects of 10 samples of Lepidium meyenii on proliferation of rat leydig cells were measured. After the process of MS data using principal component analysis (PCA) methods, the samples from Yunnan and Peru were distinguished effectively. Subsequently, the grey relational degree analysis (GRA) and partial least squares analysis (PLS) were employed to reveal the correlation between common peaks of ESI fingerprint of Lepidium meyenii from different geographical origins and proliferation activity of rat leydig cells. The results suggested that most low-polarity constituents from Lepidium meyenii had good activities on proliferation of rat leydig cells, in which N-benzylhexadecanamide and N-benzy-(9Z,12Z,15Z)-octadecatrienamide exhibited the highest activities. In addition, the proposed procedure could also be used as a simple, quick reference method to screen the active components promoting Leydig cell proliferation in traditional Chinese medicine.
The low-polarity constituents from Lepidium meyenii in Yunnan and Peru were detected by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The effects of 10 samples of Lepidium meyenii on proliferation of rat leydig cells were measured. After the process of MS data using principal component analysis (PCA) methods, the samples from Yunnan and Peru were distinguished effectively. Subsequently, the grey relational degree analysis (GRA) and partial least squares analysis (PLS) were employed to reveal the correlation between common peaks of ESI fingerprint of Lepidium meyenii from different geographical origins and proliferation activity of rat leydig cells. The results suggested that most low-polarity constituents from Lepidium meyenii had good activities on proliferation of rat leydig cells, in which N-benzylhexadecanamide and N-benzy-(9Z,12Z,15Z)-octadecatrienamide exhibited the highest activities. In addition, the proposed procedure could also be used as a simple, quick reference method to screen the active components promoting Leydig cell proliferation in traditional Chinese medicine.
2016, 44(11): 1742-1747
doi: 10.11895/j.issn.0253-3820.160244
Abstract:
A novel method was developed for the simultaneous determination of 6 novel brominated flame retardants (NBFRs), 8 polybrominated diphenyl ethers (PBDEs), tetrabromobisphenolA (TBBPA) and α, β, γ-hexabromocyclododecane (α, β, γ-HBCD) in dairy product. Dairy product samples were extracted using soxhlet extraction with acetone/hexane (1:1, V/V). The removal of co-extracted materials was achieved by gel permeation chromatography followed by acidified silica treatment. The fractionation of the PBDEs/NBFRs and HBCD/TBBPA was performed using a Supelco LC-Si SPE cartridge. The detection of the PBDEs and NBFRs was then performed by GC-NCI/MS, and that of the HBCDs and the TBBPA was performed using HPLC-MS/MS. A recovery test was performed using a matrix spiking test and for most of the analytes the recoveries ranged from 80.1% to 114.7% with RSDs equal to or lower than 14.9%. The LODs were 0.2-119.2 pg/g. This methodology was validated to be accurate and sensitive for the simultaneous pretreatment and analysis of brominated flame retardants in dairy product.
A novel method was developed for the simultaneous determination of 6 novel brominated flame retardants (NBFRs), 8 polybrominated diphenyl ethers (PBDEs), tetrabromobisphenolA (TBBPA) and α, β, γ-hexabromocyclododecane (α, β, γ-HBCD) in dairy product. Dairy product samples were extracted using soxhlet extraction with acetone/hexane (1:1, V/V). The removal of co-extracted materials was achieved by gel permeation chromatography followed by acidified silica treatment. The fractionation of the PBDEs/NBFRs and HBCD/TBBPA was performed using a Supelco LC-Si SPE cartridge. The detection of the PBDEs and NBFRs was then performed by GC-NCI/MS, and that of the HBCDs and the TBBPA was performed using HPLC-MS/MS. A recovery test was performed using a matrix spiking test and for most of the analytes the recoveries ranged from 80.1% to 114.7% with RSDs equal to or lower than 14.9%. The LODs were 0.2-119.2 pg/g. This methodology was validated to be accurate and sensitive for the simultaneous pretreatment and analysis of brominated flame retardants in dairy product.
2016, 44(11): 1748-1754
doi: 10.11895/j.issn.0253-3820.160255
Abstract:
A method was established to analyze the dissolved Xe concentration and Xe isotopes in water precisely with the self-design device of Xe extraction and separation line in combining with the Helix SFT noble gas mass spectrometer. The leak test and the background determination of the whole system proved the system was reliable. The large amount of Argon from Xe could be effectively removed by cycling temperature rising and falling method, which resulted in the elimination of the interference to the analysis of Xe concentration and isotopes. The limit of detection of the method for Xe concentration could reach as low as 10-13-10-14 L/L. The method was used for the measurement of the dissolved Xe in air saturated water (ASW), and the RSDs of Xe concentration, 129Xe/131Xe and 132Xe/134Xe were 1.0%, 0.10% and 0.20% respectively, while the errors were 0.93%, 0.16% and 0.50% respectively.
A method was established to analyze the dissolved Xe concentration and Xe isotopes in water precisely with the self-design device of Xe extraction and separation line in combining with the Helix SFT noble gas mass spectrometer. The leak test and the background determination of the whole system proved the system was reliable. The large amount of Argon from Xe could be effectively removed by cycling temperature rising and falling method, which resulted in the elimination of the interference to the analysis of Xe concentration and isotopes. The limit of detection of the method for Xe concentration could reach as low as 10-13-10-14 L/L. The method was used for the measurement of the dissolved Xe in air saturated water (ASW), and the RSDs of Xe concentration, 129Xe/131Xe and 132Xe/134Xe were 1.0%, 0.10% and 0.20% respectively, while the errors were 0.93%, 0.16% and 0.50% respectively.
2016, 44(11): 1755-1762
doi: 10.11895/j.issn.0253-3820.160224
Abstract:
A urinary untargeted metabonomics method based on UPLC/Q-TOF-MS was established to investigate the mechanism of compatibility of Panax ginseng and Veratrum nigrum in Spleen qi deficiency rat. Spleen qi deficiency rat model was established, then the exhaustive swimming time and the content of white blood cells, red blood cell and hemoglobin in the blood was detected after administration for 15 days. The results showed that Panax ginseng could increase the exhaustion swimming time (p<0.01) and the content of white blood cells, red blood cell and hemoglobin in the blood (p<0.05, p<0.01) of spleen qi deficiency rats, and Veratrum nigrum or compatible application had no significant effect index mentioned above (p>0.05). The urinary metabolic profiling was analyzed by using UPLC/Q-TOF-MS and the obtained data were analyzed by PCA. The score of PCA showed that there was significant difference among the metabolic profile of different groups. According to the results of OPLS-DA and the databases, fifteen potential biomarkers were identified as the therapeutic effect of Panax ginseng, and seven of them and their pathways were considered as reducing the therapeutic effect of Panax ginseng by co-administration with Veratrum nigrum. The results indicated that the effect of Panax ginseng on promoting energy metabolism, regulating immune and antioxidation in the spleen qi deficiency rats were decreased after the compatibility of Panax ginseng and Veratrum nigrum.
A urinary untargeted metabonomics method based on UPLC/Q-TOF-MS was established to investigate the mechanism of compatibility of Panax ginseng and Veratrum nigrum in Spleen qi deficiency rat. Spleen qi deficiency rat model was established, then the exhaustive swimming time and the content of white blood cells, red blood cell and hemoglobin in the blood was detected after administration for 15 days. The results showed that Panax ginseng could increase the exhaustion swimming time (p<0.01) and the content of white blood cells, red blood cell and hemoglobin in the blood (p<0.05, p<0.01) of spleen qi deficiency rats, and Veratrum nigrum or compatible application had no significant effect index mentioned above (p>0.05). The urinary metabolic profiling was analyzed by using UPLC/Q-TOF-MS and the obtained data were analyzed by PCA. The score of PCA showed that there was significant difference among the metabolic profile of different groups. According to the results of OPLS-DA and the databases, fifteen potential biomarkers were identified as the therapeutic effect of Panax ginseng, and seven of them and their pathways were considered as reducing the therapeutic effect of Panax ginseng by co-administration with Veratrum nigrum. The results indicated that the effect of Panax ginseng on promoting energy metabolism, regulating immune and antioxidation in the spleen qi deficiency rats were decreased after the compatibility of Panax ginseng and Veratrum nigrum.
2016, 44(11): 1763-1770
doi: 10.11895/j.issn.0253-3820.160356
Abstract:
A sensitive method was developed for the simulation determination of six kinds of sulfur mustards (HD) biomarkers (TDGO, SBMSE, SBSNAE, TDG, MSMTESE and SMO) in human plasma by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). HD exposed plasma samples were pretreated with a mixed solvent of methanol and acetonitrile to precipitate proteins. A solid phase extraction (SPE) method with HLB cartridge was used to purify the target biomarkers from the matrix. A complete separation was achieved on an UHPLC system with a gradient elution. The qualitative and quantitative analyses were carried out by triple quadrupole tandem mass spectrometry in multiple reaction monitoring (MRM) mode. The results showed that the calibration curves for the 6 biomarkers were linear(R2=0.9840-0.9955)over the range from 0.05 to 500 ng/mL, with the limits of detection (LODs) of 0.01-1.0 ng/mL. The relative standard deviation (RSD, n=5) was ≤ 5.5%, and the recovery of the analytes ranged from 86.5% to 110.8%. The influence of the matrix backgrounds on the method's robustness was effectively diminished by introducing SPE procedure and by optimizing the UHPLC elution program. The method was successfully applied to the fifth biomedical sample analysis exercise organized by the Organization for the Prohibition of Chemical Weapons (OPCW).
A sensitive method was developed for the simulation determination of six kinds of sulfur mustards (HD) biomarkers (TDGO, SBMSE, SBSNAE, TDG, MSMTESE and SMO) in human plasma by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). HD exposed plasma samples were pretreated with a mixed solvent of methanol and acetonitrile to precipitate proteins. A solid phase extraction (SPE) method with HLB cartridge was used to purify the target biomarkers from the matrix. A complete separation was achieved on an UHPLC system with a gradient elution. The qualitative and quantitative analyses were carried out by triple quadrupole tandem mass spectrometry in multiple reaction monitoring (MRM) mode. The results showed that the calibration curves for the 6 biomarkers were linear(R2=0.9840-0.9955)over the range from 0.05 to 500 ng/mL, with the limits of detection (LODs) of 0.01-1.0 ng/mL. The relative standard deviation (RSD, n=5) was ≤ 5.5%, and the recovery of the analytes ranged from 86.5% to 110.8%. The influence of the matrix backgrounds on the method's robustness was effectively diminished by introducing SPE procedure and by optimizing the UHPLC elution program. The method was successfully applied to the fifth biomedical sample analysis exercise organized by the Organization for the Prohibition of Chemical Weapons (OPCW).
2016, 44(11): 1771-1779
doi: 10.11895/j.issn.0253-3820.160626
Abstract:
Cysteine thiols have high reaction activity and play significant roles in protein structures and functions as the sites of nucleophilic, redox catalysis, metal binding and allosteric regulation. Due to the reactivity of the thiol group, cysteine residues are very prone to post-translational modifications (PTMs) such as oxidation, lipidation, and so on, which can regulate/damage protein functions and are associated with many diseases. Thus, it is very important to qualitatively and quantitatively analyze PTMs in the cysteine residues for further understanding its biological functions. This review mainly focuses on the development of mass spectrometric and high-throughput proteomic approaches for investigating some commoncysteine post-translational modifications.
Cysteine thiols have high reaction activity and play significant roles in protein structures and functions as the sites of nucleophilic, redox catalysis, metal binding and allosteric regulation. Due to the reactivity of the thiol group, cysteine residues are very prone to post-translational modifications (PTMs) such as oxidation, lipidation, and so on, which can regulate/damage protein functions and are associated with many diseases. Thus, it is very important to qualitatively and quantitatively analyze PTMs in the cysteine residues for further understanding its biological functions. This review mainly focuses on the development of mass spectrometric and high-throughput proteomic approaches for investigating some commoncysteine post-translational modifications.
2016, 44(11): 1780-1785
doi: 10.11895/j.issn.0253-3820.160455
Abstract:
Half round rod electrode linear ion trap (HreLIT) has many advantages such as simple structure, ease of manufacture and high assembly accuracy. A novel HreLIT with slot on each electrode was proposed to improve the performance of HreLIT. The ratio of field radius and electrode radius (r/r0) and "stretch" distance were optimized to improve the performance of HreLIT. In this study, mass spectrum was achieved by ion trajectory simulation in HreLITs with different geometry and dimension, and mass resolution and ion abundance were used to evaluate the performance of HreLIT. The results showed that the performance of HreLIT with r/r0=5:5 was significantly improved when "stretch" distance ranged from 0.8 to 1.2 mm. And the best mass resolution was achieved when the "stretch" distance was 0.9 mm. When the scan rate was about 409 Da/s, a mass resolution up to 6264 (M/ΔM, FWHM) was achieved for ions with m/z=609 Da. For comparison, linear ion trap with hyperbolic electrodes was also simulated and optimized, and it was shown that the performance of optimized HreLIT was equal to that of linear ion trap with hyperbolic electrodes.
Half round rod electrode linear ion trap (HreLIT) has many advantages such as simple structure, ease of manufacture and high assembly accuracy. A novel HreLIT with slot on each electrode was proposed to improve the performance of HreLIT. The ratio of field radius and electrode radius (r/r0) and "stretch" distance were optimized to improve the performance of HreLIT. In this study, mass spectrum was achieved by ion trajectory simulation in HreLITs with different geometry and dimension, and mass resolution and ion abundance were used to evaluate the performance of HreLIT. The results showed that the performance of HreLIT with r/r0=5:5 was significantly improved when "stretch" distance ranged from 0.8 to 1.2 mm. And the best mass resolution was achieved when the "stretch" distance was 0.9 mm. When the scan rate was about 409 Da/s, a mass resolution up to 6264 (M/ΔM, FWHM) was achieved for ions with m/z=609 Da. For comparison, linear ion trap with hyperbolic electrodes was also simulated and optimized, and it was shown that the performance of optimized HreLIT was equal to that of linear ion trap with hyperbolic electrodes.
2016, 44(11): 1786-1792
doi: 10.11895/j.issn.0253-3820.160557
Abstract:
A novel time-of-flight mass spectrometer which adopted high sensitivity electron impact ionization source and orthogonal-injected two-stage-reflector mass analyzer structure was developed for the combination with comprehensive two-dimensional gas chromatography. With 20 kHz of extraction frequency, the mass detection range and mass resolution of this instrument were from 1 to 1000 amu and better than 1000 (m/z=219, ADC card), respectively, with a detection limit of less than 1 pg and a linear range more than 4 orders of magnitude. Meanwhile the instrument has a high acquisition speed of 400 spectra per second, which made it satisfy for combination with comprehensive two-dimensional gas chromatography. For the moment, this mass spectrometer combined with the first domestic comprehensive two-dimensional gas chromatography was successfully used for the detection of many complicated samples in the field of petroleum, environment and essence, revealing its ability for connecting with the comprehensive two-dimensional gas chromatography and the application potential for full component analysis of complex system.
A novel time-of-flight mass spectrometer which adopted high sensitivity electron impact ionization source and orthogonal-injected two-stage-reflector mass analyzer structure was developed for the combination with comprehensive two-dimensional gas chromatography. With 20 kHz of extraction frequency, the mass detection range and mass resolution of this instrument were from 1 to 1000 amu and better than 1000 (m/z=219, ADC card), respectively, with a detection limit of less than 1 pg and a linear range more than 4 orders of magnitude. Meanwhile the instrument has a high acquisition speed of 400 spectra per second, which made it satisfy for combination with comprehensive two-dimensional gas chromatography. For the moment, this mass spectrometer combined with the first domestic comprehensive two-dimensional gas chromatography was successfully used for the detection of many complicated samples in the field of petroleum, environment and essence, revealing its ability for connecting with the comprehensive two-dimensional gas chromatography and the application potential for full component analysis of complex system.
2016, 44(11): 1793-1797
doi: 10.11895/j.issn.0253-3820.150978
Abstract:
As a novel linear ion trap, the triangular-electrode linear ion trap (TeLIT) has simple structure and good performance. The relationship between its geometry and performance was investigated. Ion trajectories and mass peaks of TeLIT with different ratios of field radius (rx/ry) were analyzed by using simulation software SIMION and AXSIM. It was shown that the performance of the TeLIT could be enhanced by optimizing rx/ry which would improve internal electric fields distribution. The optimum mass resolution of 8387 was achieved for ions with m/z 1892 Th at rx/ry=5.75/5 when scan rate was 1500 Th/s. When the scan rate was decreased to about 300 Th/s, the resolving power of the mass spectrum was in excess of 23000.
As a novel linear ion trap, the triangular-electrode linear ion trap (TeLIT) has simple structure and good performance. The relationship between its geometry and performance was investigated. Ion trajectories and mass peaks of TeLIT with different ratios of field radius (rx/ry) were analyzed by using simulation software SIMION and AXSIM. It was shown that the performance of the TeLIT could be enhanced by optimizing rx/ry which would improve internal electric fields distribution. The optimum mass resolution of 8387 was achieved for ions with m/z 1892 Th at rx/ry=5.75/5 when scan rate was 1500 Th/s. When the scan rate was decreased to about 300 Th/s, the resolving power of the mass spectrum was in excess of 23000.
