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OBJECTIVE: To establish a method for detecting resorcinol in workplace air by gas chromatography with capillary column. METHODS: The resorcinol in workplace air was collected into muiti-hole absorbing tubes with distilled water and detected by capillary chromatographic column by direct injection. RESULTS: The good linear range of resorcinol was 1.7-200.0 mg/L. The correlation coefficient was 0.999 9. The detection limit was 0.5 mg/L and the lower limit of quantitation was 1.7 mg/L. The minimum detection concentration was 0.7 mg/m~3(sample volume was 7.5 L). The standard recovery rate was 98.5%-102.6%. The within-run relative standard deviation(RSD) was 0.7%-3.6% and the between-run RSD was 1.8%-5.7%. CONCLUSION: This method has high sensitivity, accuracy and can effectively remove interference, which is suitable for determination of resorcinol in workplace air.
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OBJECTIVE: To establish a methodology for the detection of cyclohexanone in workplace air by capillary column gas chromatography.METHODS: The air sample in the workplace was collected with activated carbon tube and desorbed with carbon disulfide.The extracts were separated by FFAP capillary column and detected with flame ionization detector,and quantified using standard curve.RESULTS: The linearity range of cyclohexanone was 10.00-1 000.00 mg/L,and the correlation coefficient was 0.999 9.The detection limit and the lower limit of quantification were 1.31 and 4.37 mg/L,respectively.The minimum detectable concentration and the minimum quantitative mass concentration were 4.37 and13.11 mg/m~3,respectively.The average desorption efficiency of cyclohexanone was 95.80%-97.88%.The within-run and between-run relative standard deviation were 0.52%-3.12% and 3.28%-4.75% respectively.The samples could be stored at room temperature for 7 days.CONCLUSION: This method is simple and accurate.It is suitable for the determination of a large number of samples.
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Objective:To establish a method for the determination of 9 residual solvents including methanol, ethanol, acetone, i-sopropyl alcohol, acetonitrile, dichloromethane, methyl-butyl ether, ethyl acetate and methylbenzene by capillary gas chromatography. Methods:The residual solvents were separated on a Kromat KB-624(30 m × 0. 53 mm,3. 0 μm) capillary chromatographic column with temperature programming. Nitrogen was used as the carrier gas with the flow rate of 5. 0 ml·min-1 . The temperature of injector was 200 ℃. A flame ionization detector was used with the temperature of 250℃. The containers of head-space injector were in equilib-rium at 80℃ for 20 min. Dimethyl sulfoxide was used as the solvent and an external standard method was used for the determination of the 9 residual solvents. The injection volume was 1 ml. Results:Under the above conditions, the 9 solvents were well separated. There was good linear relationship within the concentration range, and the correlation coefficients were no less than 0. 9991. The average re-coveries were 99. 08%-105. 14% with RSD of 1. 1%-3. 3%(n=9). The LOQ was 15. 68, 25. 45, 1. 09, 10. 61, 4. 54, 5. 73, 1. 04, 10. 58 and 1. 89 μg, respectively. Conclusion:The established method is simple, accurate and reproducible, and can be used in the determination of residual solvents in irbesartan API.
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Objective A headspace-gas chromatography method was established for determination of methanol in Huox-iang Zhengqi Tincture. Methods Headspace-gas chromatography was performed on a HP-INNOWAX capillary col-umn, with nitrogen as carrier gas and FID as detector. The injector temperature was at 150℃ and the detector tempera-ture was at 200℃ , and temperature programming and split stream sampling were used. Results A good linearity was obtained within the designed range, the average recovery was 98.89 % with the RSD of 1.36 %, which met the correla-tive criterion of China Pharmacopoeia. Conclusion This method is proved to be accurate, and it has a good reproducibil-ity and can be used to determinate the residual methanol in Huoxiang Zhengqi Tincture.
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Objective To explore the feasibility for determination of chloroform and tetrachloromethane in drinking water with DB-5, Rtx-1 and DB-1 capillary columns. Methods For the mild solubility of chloroform and tetrachloromethane in drinking water, chloroform and tetrachloromethane were analysed by static headspace gas chromatography with DB-5, Rtx-1 and DB-1 capillary columns and electron capture detectorECD, external standard method was used for quantification. Results Three kinds of columns were used for determination of chloroform and tetrachloromethane,the retention time was lower than 3 min, for chloroform and tetrachloromethane the average recovery rates were 92.06%-104.95% and 78.33%-103.22% respectively, RSD were 2.06%-2.71% and 1.76%-5.59% respectively. Conclusion DB-5, Rtx-1 and DB-1 capillary columns are suitable for determination of chloroform and tetrachloromethane in drinking water.
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Objective To develop a method to determine iodine of water. Methods Samples were derivatively treated and injected at no split injection mode into GC analysis system with the capillary column and ECD. Results Compared with the sanitary regulations of drinking water defined in 2001 China, the determination method showed a lowest detection mass of 0.001 ng, a linear range of 1.0-10 ?g/L and a detection limit of 1 ?g/L. RSDs and recovery rates were 2.5%-3.4% and 96.3%-101.5%. Conclusion This method is simple and the detection limit is low, the linear range is acceptable.
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Objective To establish a method for simultaneous determination of 12 kinds of organophosphorus pesticides in water. Methods Organophosphorus pesticides in the water were extracted by liquid-liquid extraction, then analyzed with DB-1701 capillary column. In the same time, they were determined with GC by controlling the temperature and the speed of nitrogen. Retention time of the peaks was used for qualitative analysis, while external standard method was used for the quantitative analysis. Results The linear ranges of organophosphorus pesticides were 0.2～50.0 ?g/L, r≥0.999 1. The lowest detection limit was 0.009～0.04 ?g/L, the rate of recovery were 78.4%～93.9% and RSDs were 3.4%～7.5%. Conclusion This method is simple, rapid, sensitive and can efficiently separate and determine 12 kinds of organophosphorus pesticides in the water with 32.5 minutes of operation only.
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Objective To establish a method for simultaneous determination of 6 kinds of organophosphorus pesticides in water.Methods The liquid-liquid extraction,gas chromatography with RTX-50 capillary column and flame photometric detector were used to determine 6 kinds of organophosphorus pesticides(DDVP,dimethoate,malathion,methyl parathion,parathion,chlorpyrifos)in water.Results Chromatographic resolutions for the above 6 kinds of organophosphorus pesticides were both over 1.5.The linear range was 2.0-16.0 ?g/ml(r=0.999 2～0.999 8),the detection limits were 0.009 2～0.076 ng,RSDs were 1.5%-7.1%,the average recovery rates were 93.0%-98.7%.6 kinds of organophosphorus pesticides could be absolutely separated on RTX-50 capillary column.Conclusion This method presents an advantage in detection limit,precision and accuracy compared with that in GB13192-1991,it will meet the requirement of Sanitary Standard for Drinking Water and routine water quality analysis.
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Objective To establish a method for determination of p-phenylenediamine,m-phenylenediamine,o-phenylenediamine in oxidative-type hair dyes.Methods The samples of oxidatve-type hair dyes were solved by ethyl acetate,then followed by centrifuged,extracted.The extraction was qualitatively and quantitatively analyzed by gas chromatography,the working condition was optimized also.Results The linear range for p-phenylenediamine,m-phenylenediamine,o-phenylenediamine was 25-400 ?g/ml,r=0.999 1-0.999 9,the detection limits were 3.1,3.6,3.4 ?g/ml respectively,the standard recovery rates were 86.8%-104.3%,RSDs were 2.3%-4.5%(n=3).Conclusion This method was simple and rapid,it can be effectively applied in extraction and separation of phenylenediamine in oxidative-type hair dyes.
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AIM: To establish the method of determining methylbenzene、dimethylbenzene、divinylbenzene、and phenylethene in gardenia extract. METHODS: The GC system consisted of DB-INNOWax capillary chromatographic column,nitrogen as the carrier gas,and FID as the detector. RESULTS: Methylbenzene was less than 890 mg/L,dimethylbenzene 2 170 mg/L,divinylbenzene and phenylethene 2000 mg/L,vespectively in gardenia extract. The average recoveries were within 96.8%~104.4%.The limits of detection were 0.125 mg/L-2.87 mg/L. CONCLUSION: The method is sensitive,accurate and reproducible,and it can be used to control the quality of gardenia extract.
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The ratio of concentrations of D-aspartic acid and L-aspartic acid in dentin of 27 premoars of different ages was determined with chiral capillary column gas. chromatography. Acidic isopropanol and trifluoroacetic acid anhydride were derivative agents. The linear regression between the degree of racemization and age was established, r= 0. 9568, SD= 4. 5 years. This seems to be a new method which is more accurate and objective than others in age estimation with teeth.