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OBJECTIVE: To explore a method for detecting volatile organic compounds(VOCs) in air by a portable gas chromatography-mass spectrometer(GC-MS). METHODS: A portable GC-MS hand-held probe was used for sampling and detection. All effluent components were qualitatively analyzed by the standard spectral library of the United State National Institute of Standards and Technology. The percentage of peak area of the component was calculated by normalization method. The static distribution method was adopted in the semi-quantitative and quantitative analysis using nitrogen as the diluting gas to prepare different mass concentration of 13 kinds of VOCs in the mixed standard gas. The retention time and characteristic ions were used for qualitative analysis, and the quantitated full scanning mode was used for quantitative analysis.RESULTS: The minimum detected mass concentration of the 13 chemical harmful factors was 0.02-0.10 mg/m~3, and the minimum quantitative mass concentration was 0.07-0.38 mg/m~3. The recovery rate was 84.76%-116.56%, and the within-and between-run relative standard deviations were 4.10%-12.50% and 8.17%-14.36%, respectively. CONCLUSION: The portable GC-MS instrument could be used for qualitative alalysis, peak area percentage determination, semi-quantitative and quantitative analysis of VOCs in the workplace air or sudden chemical poisoning accidents.
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The components of volatile oils are generally complex, and they often have the functions of divergent dissolving surface, insecticidal and antibacterial. However, there are few reports on bacteriostasis, anti-inflammation and antioxidation roles of volatile oils of Pelargonium graveolens L'Herit. The volatile oil of Pelargonium graveolens L’Herit. was extracted by steam distillation, and GC-MS and peak area normalization analysis showed that it mainly contained 30 compounds, and the identified components accounted for 90.26% of the total peak area. The volatile oil of Pelargonium graveolens L'Herit. has a certain inhibitory effect on Candida albicans and Staphylococcus aureus, especially on Candida albicans. The diameter of the bacteriostatic zone is 15.55±1.53 mm by using the oxford cup method. Dexamethasone and low, middle and high doses of volatile oils of Pelargonium graveolens L'Herit. were given after the RAW264. 7 cell inflammatory model and was induced by lipopolysaccharide (LPS = 10.0 μg/mL). ELISA assays showed that it could effectively reduce the expression of IL-1β and TNF-α in inflammatory cells, and the effect of high doses was similar to that of IL-1β and TNF-α in the dexamethasone group. GC-MS was successfully used to determine and identify the chemical constituents of volatile oils from Pelargonium graveolens L'Herit. in this study. We show that the volatile oil of Pelargonium graveolens L'Herit. had certain bacteriostatic activity and effectively reduces the secretion of IL-1β and TNF-α by inflammatory cells. It provides an experimental basis for the development and utilization of volatile oils from Pelargonium graveolens L'Herit.
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Trichoderma spp. is a kind of filamentous fungi with important biocontrol value. Twelve strains of Trichoderma spp. were isolated from the soils of different types of crops in Shaoxing, Zhejiang and Foshan, Guangdong. The antagonistic resistance to Fusarium oxysporum was compared by plate confrontation test. The further analysis of volatile secondary metabolites for two strains were carried out using HS-SPME-GC-MS analysis. The results showed that T. asperellum ZJSX5003 and GDFS1009 had fast growth ability, and the inhibition effects on F. oxysporum were 73% and 74% respectively. Six identical volatile metabolites were detected as follows 2-Methyl-1-propanol, 3-Methyl-1-butanol, 3-Methyl-3-buten-1-ol, Acetyl methyl carbinol, Butane-2,3-diol and 6-n-pentyl-2H-pyran-2-one (6-PAP). Among them, 6-PAP was validated to have a higher inhibitory effect on F. oxysporum in vitro. This study will provide basis for the development of biocontrol agents with metabolites of Trichoderma, such as 6-PAP.
Subject(s)
Antibiosis , Antifungal Agents , Pharmacology , Fusarium , Physiology , Gas Chromatography-Mass Spectrometry , Trichoderma , Chemistry , MetabolismABSTRACT
OBJECTIVE: To establish a method for simultaneously detecting methyl methacrylate, ethyl methacrylate, n-propyl methacrylate and butyl methacrylate in workplace air by a portable gas chromatography-mass spectrometer(GC-MS) technique. METHODS: The portable GC-MS hand-held probe was used for sampling and detection. Samples were separated with DB-5 rapid chromatographic column in order to maintain retention time and characteristics of the ions, and quantified by standard curve method. RESULTS: The linear correlation of this method was higher than 0.999 0. The minimum detection concentration was 0.03-0.06 mg/m~3, and the minimum quantitation concentration was 0.10-0.20 mg/m~3. The standard recovery rate was 82.22%-91.24%. The within-run and the between-run relative standard deviation were 7.67%-14.63% and 10.40%-13.79% respectively. CONCLUSION: The portable GC-MS technique could be used for qualitative and quantitative detection of above-mentioned four methylacrylate compounds in workplace air.
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Objective@#To establish a method of calibration and performance verification of the GCMS-QP 2010 Ultra gas chromatography-mass spectrometer for urine organic acid detection after annual maintenance, so as to ensure that the performance of the detection system can continuously meet the detection needs. @*Methods@#According to the requirements of the equipment manufacturer and the Calibration Specifications for Benchtop Gas Chromatography-Mass Spectrometer, the gas chromatography-mass spectrometer was calibrated after annual maintenance. According to the CNAS-CL02-A003 Guidance on the Application of Accreditation Criteria for the Medical Laboratory Quality and Competence in the Field of Clinical Chemistry, the analytical performance of the maintained gas chromatography-mass spectrometer was validated. @*Results@#The calibration results of quality range, quality accuracy, resolution, signal-to-noise ratio and repeatability were all met the requirements. The detection results of internal quality control materials were under control, and the results of retained samples kept unchanged. @*Conclusion@#The calibration and performance verification method of the gas chromatography-mass spectrometer for urine organic acid detection after annual maintenance is established successfully, which is of importance for providing accurate and reliable results of urine organic acid.
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OBJECTIVE: To establish a detection method for 1-bromopropane in human urine by headspace gas chromatography-mass spectrometry( GC-MS). METHODS: A 4. 00 m L portion of the urine sample was placed in a 15. 00 m L headspace vial and 20. 00 μL of 1-bromobutane internal standard solution( 204. 200 mg / L mass concentration) was added.The bottle cap was immediately sealed. The sample was heated to 80 ℃ with an equilibrium time of 20 minutes in the headspace device. The vapor in the headspace vial was separated by GSBP-FFAP( 30. 00 m × 0. 25 mm × 0. 25 μm)capillary chromatography column and the ion was used to carry out quantitative determination of 1-bromopropane in human urine. RESULTS: The good linearity range of 1-bromopropan mass concentration was 0. 025-1. 012 mg / L, and the correlation coefficient was 0. 999 8. The detection limit was 7. 5 μg / L( urine sample volume,4. 00 m L) and the limit of quantitation was 25. 0 μg / L( urine sample volume,4. 00 m L). The relative standard deviation( RSD) of within-run precision was 2. 61%-4. 08%,and the RSD of between-run precision was 2. 79%-6. 25%. The average recovery rate was99. 34%-105. 94%. CONCLUSION: The method of determining 1-bromopropane in human urine by headspace GC-MS has the features of high sensitivity,good linear relationship,low interference,good precision and easy operation,which is suitable for detecting 1-bromopropane mass concentration in human urine.
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Objective To explore the difference of serum free fatty acid(FFA) composition between the patients with the metabolic syndrome(MS) and the patients with high risk for MS(HRMS),and the relationship of FFA composition with their serum glucose.Methods The serum fatty acid profile was measured with the gas chromatography and mass spectrometer(GC/MS)in 159 patients with MS or HRMS and 43 control subjects.Results The contents of unsaturated fatty acid(UFA,C18:2 and C20:3),the ratios of UFA/TFA(total fatty acid),PUFA(polyunsaturated fatty acid)/TFA and PUFA/SFA(saturated fatty acid) were significantly increased in patients with MS than those in the normal controls(P0.05).FBG had remarkably positive correlation with UFA/TFA,PUFA/TFA and PUFA/SFA(r=0.229,0.204,0.230,P