The method of determination for butyronitrile and isobutyronitrile in the air of workplace by dissolved desorption-gas chromatography / 中华劳动卫生职业病杂志

Objective: To establish a method for the determination of butyronitrile and isobutyronitrile in the air of workplace by gas chromatography. Methods: In March 2020, butyronitrile and isobutyronitrile in the air of workplace was collected by silica gel, eluted with methanol, separated and determined by gas chromatogram with flame ionization detector, the characteristics of determination of nitrile and isobutyronitrile by gas chromatography were analyzed. Results: The limit of detection for butyronitrile and isobutyronitrile was 0.33 μg/ml. The linear range of butyronitrile determined by this method was 1.60-1600.00 μg/ml, y=2.295x-3.480, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.43%-4.12%, the between-run precisions were 1.72%-3.70%, and the desorption rates were 93.26%-98.41%. The linear range of isobutyronitrile determined by this method was 1.52-1520.00 μg/ml, y=2.208x-0.102, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.52%-3.22%, the between-run precisions were 1.20%-3.82%, and the desorption rates were 96.85%-102.50%. The sealed samples could be stored at least 10 days at room temperature without significant loss. Conclusion: The method has the advantages of good precision, high sensitivity and simple operation. It is suitable for the simultaneous determination of butyronitrile and isobutyronitrile in the air of workplace.

Rapid determination of 30 volatile organic compounds in workplace air by gas chromatography / 中华劳动卫生职业病杂志

Objective: To establish a method for rapid detection of DB-WAX capillary column and determination of the workplace air in 30 kinds of volatile organic pollutants. Methods: In August 2020, N-pentane, n-hexane, methylcyclohexane, octane, Acetone, ethyl acetate, butanone, benzene, 3-pentanone, trichloroethylene, tetrachloroethylene, toluene, butyl acetate, 2-hexanone, Isoamyl acetate, ethylbenzene, p-xylene, m-xylene, amyl acetate, o-xylene, chlorobenzene, styrene, cyclohexanone, P-chlorotoluene, bromobenzene, M-dichlorobenzene, p-dichlorobenzene, O-dichlorobenzene, o-Chlorotoluene, 1, 2 , 4-trichlorobenzene of 30 kinds of substances in air were collected by activated carbon tube. After analysis by carbon disulfide, the analytical solution was analyzed by DB-WAX column and determined by FID detector. Results: The above 30 kinds of volatile organic pollutants had good separation effect, the correlation coefficient of the standard curve was above 0.999, the relative standard deviation was 0.1%-3.2%, the desorption efficiency was 77.0%-117.1% , the lower limit of quantitation was 0.33-5.33 μg/ml, and the lowest quantitation concentration was 0.22-3.55 mg/m(3), the recoveries ranged was 95.4%-104.9%. Conclusion: The method can effectively separate and accurately determine 30 volatile organic compounds in these workplaces, and the method is simple and quick.

Evaluación de las características fisicoquímicas y de la actividad antimicrobiana del aceite del árbol de té contra Cutibacterium acnes (Propionibacterium acnes) ATCC 6919 / Evaluation of tea tree oil physicochemical features and its antimicrobial activity against Cutibacterium acnes (Propionibacterium acnes) ATCC 6919

Resumen: Introducción. El aceite del árbol de té es un aceite esencial reconocido por sus propiedades antimicrobianas. Objetivos. Evaluar la composición, características y efecto antimicrobiano del aceite al 2 % del árbol de té y su concentración inhibitoria mínima (CIM) contra Cutibacterium acnes (Propionibacterium acnes). Materiales y métodos. Se evaluó el quimiotipo en tres lotes diferentes de este aceite mediante cromatografía de gases, así como su actividad antimicrobiana en concentración al 2 % v/v y la CIM contra C. acnes mediante ensayo de difusión en agar (guía M11-A8 CLSI). Resultados. Los lotes evaluados presentaron los quimiotipos ajustados a la norma ISO 4730, lo que indicó la alta calidad del producto. Los lotes contenían de 30 a 40 % de terpinen-4-ol, compuesto que favorece la actividad antimicrobiana, la cual presentó en todos los lotes un efecto dependiente de la concentración contra C. acnes, con una inhibición del crecimiento microbiano en concentración al 2 % v/v en todas las pruebas. La concentración inhibitoria mínima fue de 0,25 % v/v. La actividad antimicrobiana del aceite del árbol de té contra este microorganismo ya ha sido reportada con una concentración inhibitoria mínima entre 0,05 y 1,25 % v/v, rango que cobija la obtenida en este estudio. Conclusiones. Los resultados evidenciaron la gran calidad de este producto y su capacidad como agente antibacteriano contra C. acnes. Se deben hacer estudios con otros aislamientos del microorganismo provenientes de pacientes con acné vulgar para confirmar su actividad general y la de cada uno de sus componentes.

Abstract: Introduction: Tea tree oil is an essential oil recognized for its antimicrobial properties. Objective: To evaluate the composition, features, and antimicrobial effect at 2% v/v, and its minimal inhibitory concentration (MIC) against Cutibacterium acnes (Propionibacterium acnes). Materials and methods: Three different batches of tea tree oil were evaluated. We characterized its chemotype by gas chromatography and its 2% v/v antimicrobial activity against C. acnes by agar diffusion assay (guide M11-A8 CLSI). Results: The three batches of oil had the chemotypes required by the ISO 4730 standard, which indicates that it is a high-quality product. Additionally, they had 30% to 40% of terpinen-4-ol, a compound that favors its antimicrobial activity. Antimicrobial activity against C. acnes for all batches had a concentration-dependent effect with microbial growth inhibitory activity in all assays at 2% v/v. The MIC obtained against C. acnes for all batches was 0.25% v/v. The antimicrobial activity of tea tree oil against this microorganism has been previously reported with a MIC between 0.05% and 1.25% v/v, a range that covers the one obtained in this study. Conclusion: These results show the high quality of the oil and its capacity as an antibacterial agent against C. acnes. New studies should be conducted to confirm its activity and that of its components in isolates of the microorganism from patients with acne vulgaris.

Determination of 1-methoxy-2-propanol in urine by headspace solid-phase microextraction coupled with gas chromatography / 中华劳动卫生职业病杂志

Objective@#To establish a method for the determination of 1-methoxy-2-propanol in urine using headspace solid phase micro-extraction coupled with gas chromatography.@*Methods@#The 1-methoxy-2-propanol was enriched by headspace solid phase micro-extraction fiber coated with carbene/polydimethylsiloxane (CAR/PDMS) . Single factor rotation method was used to optimize the conditions of extraction temperature, salt amount, and extraction time. The separation was performed on DB-5 (30 m×0.32 mm×0.25 μm) capillary column and detected with flame ionization detector. The quantification was based on the standard curve.@*Results@#The concentration of 1-methoxy-2-propanol in urine was linear in the range of 0.50-10.0 mg/L, and the linear correlation coefficient was 0.9993. The detection limit of the method was 0.14 mg/L, and the limit of quantification was 0.45 mg/L. The recovery was 85.8% to 104.7%, and the RSD of intra- and inter-batch precision were 3.25%-6.65% and 0.81%-3.96%, respectively.@*Conclusion@#The method is high sensitivity and simple operation, and is suitable for the determination of 1-methoxy-2-propanol in urine of occupational exposure population.

Determination of cyclohexanol in urine by headspace solid-phase microextraction coupled with gas chromatography / 中华劳动卫生职业病杂志

Objective@#To establish a method for determining cyclohexanol in urine by headspace solid-phase microextraction (HS/SPME) coupled with gas chromatography (GC) .@*Methods@#After the urine sample was hydrolyzed by β-glucuronidase, 2.0 g of NaCl was added, then the analyte in urine was adsorbed by a CAR/PDMS solid phase micro-extraction head in a water bath at 50 ℃ for 20 min. And the extraction head was inserted into the gas chromatograph gasification chamber to desorb, the analyte was detected after separated by the capillary through the flame ionization detector.@*Results@#The linear range of the method was 0.1-5.0 mg/L with the correlation coefficients (r) 0.999. The average recovery was 84.5%-96.3%, the inter-day precision was 3.81%-6.00%, and the detection limit was 0.03 mg/L.@*Conclusion@#The method is founded to be low detection limit, simple operation and no need of organic solvent. So it is suitable for the detection of cyclohexanol in urine of occupational exposure to cyclohexanone.

Quality control study of borneol and artificial musk in Xinfufang-Zhenzhusan and Xinfufang-Zhenzhugao / 国际中医中药杂志

Objective To establish a quality control method for bomeol and artificial musk in Xinfufang-Zhenzhusan and Xinfufang-Zhenzhugao.Methods We used petroleum ether-toluene-ethyl acetate (9:3:2)as developer for TLC to identify isoborneol and borneol and petroleum ether-dichloromethane (2:3) as developer for TLC to identificate musk ketone.Agilent 7890 B gas chromatograph,FDI detector;Column:Thermo-TG-WaxMS GC (0.25 mm × 30 m,0.25 mm) was employed;the carrier gas was high purity nitrogen and flow rate for 1 mg/ml,the injection port temperature is 200 C and detector temperature is 250 ℃;the split ratio is 10:1 and injection volume was 1 μl,using temperature programmed.Results The isoborneol,borneol and musk ketone in the range of 0.001-10 mg/ml showed good linearity.The recovery of the method is in the range of 95 ％ to 105 ％.The TLC for isobomeol,bomeol,musk ketone can be identified easily.Conclusions The method was simple and reasonable,which can be used for the quality control of borneol and artificial musk in the Xinfufang-Zhenzhusan and Xinfufang-Zhenzhugao.

Validación de una metodología analítica para determinar bifenilos policlorados en muestras de plasma sanguíneo / Validation of an analytical methodology to determine polychlorinated biphenyls in samples from blood plasma

Resumen Introducción. Los bifenilos policlorados se encuentran entre los cinco contaminantes orgánicos persistentes más tóxicos para los organismos vivos, según la Agency for Toxic Substances and Disease Registry (ATSDR) de los Estados Unidos. Objetivo. Estandarizar y validar un método analítico para la determinación y cuantificación de los bifenilos policlorados indicadores en muestras de plasma sanguíneo, mediante cromatografía de gases acoplada a espectrometría de masas. Materiales y métodos. Se fortificó un pool de plasma para hacer los ensayos en la matriz. Además, se utilizó el material de referencia NIST SRM ® 1958 (Organic Contaminants in Fortified Human Serum, Freeze-Dried) para los ensayos de veracidad y precisión intermedia. Resultados. Los porcentajes de recuperación obtenidos con la metodología estuvieron entre 88,4 y 97,5 %, y el sesgo fue menor del 20 %. Los límites de detección y cuantificación de los bifenilos policlorados indicadores policlorados fueron de 0,04 µg/L y 0,10 µg/L, respectivamente. La linealidad representada por el coeficiente de determinación (R2) varió entre 0,9866 y 0,9886. La precisión expresada como desviación estándar relativa fue menor del 20 % en todo el rango lineal de trabajo (0,5-500 µg/L). Por último, se analizaron 115 muestras de población colombiana de diferentes zonas del país y se encontraron 65 muestras positivas, de las cuales dos estuvieron por encima de los valores de control biológico en humanos (Human Biomonitoring Values, HBM- II): 7,0 µg/L, 2XΣPCB 138, 153, 180 , y otras dos, por encima del HBM-I: 3,5 µg/L, 2XΣPCB 138, 153, 180. Conclusión. El método desarrollado resultó ser preciso para el análisis de los bifenilos policlorados en muestras de plasma sanguíneo y se puede utilizar para el control biológico de estos contaminantes en población colombiana.

Abstract Introduction: Polychlorinated biphenyls are among the five most toxic persistent contaminants for living organisms according to the Agency for Toxic Substances and Disease Registry (ATSDR). Objective: To standardize and validate an analytical method to determine and quantify polychlorinated biphenyl indicators in samples from blood plasma by means of gas chromatography-mass spectrometry. Materials and methods: We fortified a plasma pool to do the matrix assays. Additionally, we used the NIST SRM® 1958 reference material for the veracity and intermediate accuracy assays. Results: Methodology recovery percentages ranged between 88.4 and 97.5%, and the bias was less than 20%. Detection and quantification limits were 0.04 µg/L and 0.10 µg/L, respectively, for all polychlorinated biphenyl indicators. The linearity represented by the determination coefficient (R2 ) varied between 0.9866 and 0.9886. Accuracy, expressed as relative standard deviation was less than 20% in all the linear work range (0.5-500 µg/L). Finally, we analyzed 115 samples from Colombian population in various zones of the country and we found 65 positive samples, from which two samples were above HBM-II (7.0 µg/L, 2XΣPCB 138, 153, 180), and two, above HBM-I (3.5 µg/L, 2XΣPCB 138, 153, 180 ). Conclusion: The method we developed is accurate for PCB analysis in blood plasma samples and could be used for biological surveillance of these contaminants in the Colombian population.

Simultaneous determination of trichloroethylene and trichloroethanol in blood by liquid-liquid extraction-gas chromatography / 中华劳动卫生职业病杂志

Objective@#To establish a method for determing the trichloroethylene(TCE)and trichloroethanol(TCOH)in blood samples by liquid-liquid extraction-gas chromatography with electron capture detector.@*Methods@#With this method,ether was used as extraction solvent and trichloromethane was used as an internal standard. The whole blood sample was extracted with ether, and dehydrated by anhydrous sodium sulfate. Then the analytes were separated on HP-5 capillary column(30m×0.32mm×0.15μm)and detected byECD.The retention time was for qualitative analysis and the internal standard was for quantitation.@*Results@#The standard curves of TCE and TCOH showed significant linearity between 95.5μg/L-7640.0μg/L(r=0.9997)and 19.0μg/L-1520.0μg/L(r=0.9992). The average recovery was 95.5%-103.6%.The intra-day and inter-day precisions(RSD)were 2.5%-6.8%(n=6)and 1.6%-4.3%(n=6) respectively. The detect limit of TCE and TCOH were 2.10 μg/L and 0.56μg/L(S/N=3)respectively.The blood can be kept 7 days at-20℃ refrigerator without significantly loss.@*Conclusion@#This method is proved to be simple,practical and highly sensitive. It can satisfy the request for the determination of blood samples of humans exposed to TCE.

Rapid determination of volatile organic compounds in workplace air by protable gas chromatography-mass spectrometer / 中华劳动卫生职业病杂志

Objective@#To establish a method for rapid determination of 47 volatile organic compounds in the air of workplace using portable gas chromatography-mass spectrometer(GC-MS).@*Methods@#The mixed standard gas with different concentration levels was made by using the static gas distribution method with the high purity nitrogen as dilution gas. The samples were injected into the GC-MS by a hand-held probe. Retention time and characteristic ion were used for qualitative analysis,and the internal standard method was usd for quantitation.@*Results@#The 47 poisonous substances were separated and determined well. The linear range of this method was 0.2-16.0 mg/m3,and the relative standard deviation of 45 volatile ovganic compounds was 3.8%-15.8%. The average recovery was 79.3%-119.0%.@*Conclusion@#The method is simple,accurate,sensitive,has good separation effect,short analysis period, can be used for qualitative and quantitative analysis of volatile organic compounds in the workplace, and also supports the rapid identification and detection of occupational hazards.

Determination of tributyl phosphate in the air of workplace by gas chromatography / 中华劳动卫生职业病杂志

Objective@#To establish a practical method forsampling and detectingtributyl phosphate intheworkplace.@*Methods@#The samples were extracted by glass fiber membrane, eluted with ether, separated by gas chromatography, and detected by flame photometric detector.@*Results@#There were good linear relationship in the minimum detection concentration was 7.2-720.0 μg/ml, and the correlation coefficient was 0.999 92. The detection limit was 0.86 μg/ml, and the minimum detection concentration was 0.14 mg/m3 (sample volume was 30 L) . Recovery rates were 99.8%-100.2%. The with-in relative standard deviations were 4.0%-5.4% and the between relative standard deviations were 2.0%-5.5%, and average samplingefficiency was about 99.1%-100.0%.@*Conclusion@#This method conforms with the requirements of "Standardization of Methods for Determination of Toxic Substance in Workplace" . Tributyl phosphate in air could be determined accurately using this method.

Determination of glycidyl methacrylate in the air of workplace captured adsorbent tube by gas chromatography / 中华劳动卫生职业病杂志

Objective@#To develop a new solid sorbent tube for capturing glycidyl methacrylate (GMA) in workplace air, and establish a complete set of method.@*Methods@#GMA in workplace air was captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 50% (V/V) dimethylformamide-carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector.@*Results@#The linear range of GMA was 0.38-604.80 mg/L, and the related coefficient was 0.999 82. The within-run and the between-run precision were 1.11%-2.80% and 2.53%-4.84% respectively. The average desorption efficiency was 93.20%-94.97%. The minimum quantification concentration and The minimum quantification concentration were 0.02 and 0.07 mg/m3 respectively (3.00 L sample) . Samples could be stored for at least 8 days at room temperature.@*Conclusion@#The newly developed solid sorbent tube and its complete set of gas chromatography method is simple, and has high sensitivity and precision, so it can be used for sampling and quantitative detection of GMA in workplace air.

Effect of the Chinese Herbal Medicinal Ingredients in Huoxiang Zhengqi Liquid on Alcohol Metabolism in Rats / 法医学杂志

OBJECTIVES@#To study the changes of alcohol content and pharmacokinetic parameter in rats after taking Huoxiang Zhengqi liquid.@*METHODS@#The rats were randomly divided into three groups and given with white alcohol at the dose of 3.0 mL/kg, low-dose and high-dose Chinese medicine liquor, respectively. The blood was collected before administration and 5 min, 10 min, 15 min, 30 min, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h and 8 h after administration by cutting rats' tails. The concentrations of alcohol in blood were detected by headspace-gas chromatography method. The main pharmacokinetic parameters were calculated by DAS 2.0, and then analyzed by SPSS 17.0.@*RESULTS@#The difference of maximum blood concentrations between high-dose Chinese medicine alcohol group and white alcohol group was statistically significant （P<0.05）. There was no significant difference in other pharmacokinetic parameters among three groups （P>0.05）.@*CONCLUSIONS@#The Chinese herbal medicinal ingredients in the Huoxiang Zhengqi liquid has no effect on the metabolism and elimination of ethanol in rats. The research provides useful reference for the qualitative assessment and processing of traffic accident cases involved in Huoxiang Zhengqi liquid and the studies related to drug-interaction.

Determination of Residual Organic Solvents in Trepibutone by Headspace Gas Chromatography / 医药导报

Objective To establish a headspace GC method for determination of residual organic solvents as methanol, ethanol,dichloromethane and n-hexane in trepibutone. Methods An external standard method was used. A DB-624 capillary column (75 m× 0.450 mm,2.55 μm) was used with a FID detector. The injector temperature was 200 ℃ and the detector temperature was 250 ℃ .The initial column temperature was 50 ℃ ,kept for 6 min,then raised to 200 ℃ at a rate of 20 ℃ ?min-1 and kept for another 12 min. Nitrogen was used as the carrier gas. The flow rate was 3. 0 mL ? min-1 . The headspace vials equilibrium temperature was 80 ℃ and the balance time was 30 min.The injection volume is 1 mL. Results A1l the solvents could be completely separated with good linear relationships.The average recoveries of the four solvents were 100.4% ( RSD =0.5%), 100.6%(RSD = 0.6%), 99.6% ( RSD = 0.8%), 98.7% ( RSD = 0.7%) ( n = 9),respectively. Conclusion The method is simple and accurate,and can be used in the determination of residual solvents in trepibutone.

Determination of Nine Residual Solvents in Grape Seed Extract by Headspace Gas Chromatography / 医药导报

Objective To establish a headspace gas chromatography method for determination of nine residual solvents in grape seed extract. Methods The residual solvents in grape seed extract were separated on DB-WAX column (30 m× 0.45 mm, 0.85 μm) with an FID detector; the injector temperature and the detector temperature was set at 220 ℃ and 250 ℃ , respectively; the chapiter pressure was 27.58 kPa; the containers of headspace injector were in equilibrium for 30 min at 80 ℃ ;the N, N-dimethylformamide was used as the solvent. Results The detected solvents were well separated. Good linear relationship of the benzene and ethanol was obtained within the range of 0.04-0.3,100-750 μg?mL-1 , respectively. Good linear relationships of the hexane, o-xylene, m-xylene, p-xylene, styrene, toluene and 1,2-diethyl benzene solvents were obtained within the range of 0.4-3.0 μg?mL-1 (r≥0.995 8), respectively. The average recoveries (n = 3) of the nine solvents were 96.35%,97.08%,97.31%,89.93%,92.35%,90.65%,88.56%,93.84%,86.51% and the RSDs were 4.38%,2.16%,3.49%, 4.19%,4.80%,4. 83%,4. 70%,5. 00%,4. 39%, respectively. Conclusion The established method is simple, rapid and accurate, which can be used for the determination of residual solvents in grape seed extract and can simultaneously provide scientific basic for quality control.

Online Liquid Chromatography-Gas Chromatography-Mass Spectrometry for Highly Sensitive Determination of 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone in Mainstream Cigarette Smoke / 分析化学

A new approach based on online coupled liquid chromatography-gas chromatography-mass spectrometry ( LC-GC / MS ) was developed for the rapid determination of 4-( methylnitrosamino )-1-( 3-pyridyl)-1-butanone (NNK) in mainstream cigarette smoke, in which a switching valve was employed to online switching between two-dimensional chromatography. The online LC-GC / MS system used in this study was built by using online gel permeation chromatography-gas chromatography-mass spectrometry except that the micro gel column was replaced by micro alkaline alumina column which was prepared by ourselves before. The NNK in mainstream cigarette smoke was collected by a Cambridge filter pad, then the pad was extracted with dichloromethane, and the extract was quantitatively analyzed by online LC-GC / MS with D4-NNK as an internal standard. Online LC-GC / MS allowed online pretreatment purification, and the sample was subjected to online LC-GC / MS without any prior purification, which reduced human error in analysis process. The injection volume of the present online LC-GC / MS could reach 40 μL, which was 20 times of that of the conventional GC / MS (2. 0 μL of injection volume), and thus significantly improved the sensitivity. Under the optimum conditions, good linearity ( r = 0. 9998) was obtained over the range of 1. 2 - 120 ng / mL. The recoveries at three spiked levels ranged from 93. 9% to 96. 0% , and the limits of detection for qualitative and quantitative detection were 0. 25 ng / mL and 0. 9 ng / mL, respectively. All the results obtained by the present method are comparable to those of standard method recommend by China National Tobacco Company.

Determination of borneol, isoborneol and menthol inBingshuang-Meisu pill by GC / 国际中医中药杂志

Objective To establish a method for the determination of borneol, isoborneol, menthol in Bingshuang-Meisu pill.Methods The capillary column PEG-20M(30 m × 0.32 mm, 0.25μm) was used, naphthalene was adopted as internal standard substances, split injection(split ratio 10:1), temperature programme, the injector temperature was 240℃, the detector temperature was 250℃.Results The linear response range of menthol, borneol, isoborneol were 13.00-104.00μg/ml, 6.80-54.40μg/ml, 5.40-43.20μg/ml and the average recovery were 97.90%, 98.05% and 97.77%, RSD were 0.98%, 1.53% and 1.40% respectively. Conclusion The method was highly sensitive, accurate, and repeatable. It can be an important method to control the standard ofBingshuang-Meisu pill.

Limit Test for Camphor in Shujin Huoxue Pills / 医药导报

Objective To establish a method for limit test of camphor in Shujin Huoxue pills. Methods A DB-WAX (30 m×0. 32 mm,0. 25 μm) capillary column was used with a programmed temperature. Results The linear range of camphor was 1. 05-210. 00 μg·mL-1(r=1. 0). The average recovery was 101. 7%(n=9, RSD=1. 2%). Conclusion The proposed method is simple, sensitive, accurate and reproducible, which is suitable for quality control of Shujin Huoxue Pills.

Determination of Organic Solvents Residue in Butoconazole Nitrate by Headspace Gas Chromatography / 医药导报

Objective To establish a gas chromatograph method for determing Chloroform, ethyl acetate and N, N-dimethyl formamide in butoconazole nitrate. Methods The samples was detected by Headspace Gas Chromatography. Temperature programming method was adpoted and FID was used as detector. The injector temperature was 200 ℃, and the detector temperature was reach 250 ℃. Nitrogen was used as carrier gas in the experiment. Results In the mentioned chromatographic conditions, Chloroform, ethyl acetate and N, N-dimethyl formamide had good linear relationships in the ranges of 0. 066-0. 588,0. 062-0. 556 and 0. 896-8. 061 μg·mL-1 respectively. The average recoveries were 99. 18%,102. 84% and 98. 71%. RSD were 3. 87%,4. 33% and 3. 71%. Conclusion The detection method is sensitive, accurate, reliable, and can be used as a quality control for butoconazole nitrate.

Determination of Residual Organic Solvents in Poly(lactic-co-glycolide) / 医药导报

Objective To establish a capillary gas chromatography( GC)method for the determination of residual organic solvents in poly( lactic-co-glycolide)( PLGA),including methanol,acetone,dichloromethane,and toluene. Methods A capillary GC method was carried out. DB-624 capillary column(30 m× 0. 32 mm,1. 80 μm)with programmed temperature chromatography was employed. The initial temperature was kept at 40 ℃ for 8 min. Then the temperature was raised to 200 ℃ at a rate of 10 ℃·min-1 . The injection port temperature was 180 ℃,and the split ratio was 10:1. The carrier gas was nitrogen. The temperature of FID was set at 250 ℃,and the sample volume was set at 3 μL. Results Four residual organic solvents consisting of methanol,acetone,dichloromethane and toluene in PLGA were completely separated. The linear range of concentration of methanol,acetone,dichloromethane and toluene was within 10. 0-50. 0( r=0. 999 8 ),16. 7-83. 3( r=0.9998),2.0-10.0(r=0.9993),and3.0-14.8(r=0.9997)μg·mL-1,respectively.Therecoveryofmethanol,acetone, dichloromethane and toluene was 99. 9%( RSD=1. 5%),100. 8%( RSD=0. 9%),100. 1%( RSD=1. 1%),and 99. 5%(RSD=0. 6%),respectively. Six batches of samples met the requirements. Conclusion The method is proven to be sensitive and accurate after the validation. It is suitable for the determination of residual organic solvents in PLGA.

Simultaneous Determination of 34 Pesticide Residues in Vegetable Oil by QuEChERS-on-line Gel Permeation Chromatography-Gas Chromatography-Mass Spectrometry / 分析化学

A method for the simultaneous determination of 34 pesticides in sunflower oil, soybean oil and corn oil was developed. The samples were extracted and purified by a modified QuEChERS method, and then the supernatant was analyzed by on-line gel permeation chromatography-gas chromatography-mass spectrometry ( GPC-GC-MS ) . The linear range was from 0 . 01 to 0 . 2 mg/L with a good correlation coefficients ( r≥0. 9913). The average recoveries of 31 pesticides (except p,p′-DDE, p,p′-DDD, p,p′-DDT. For detail, please reference to section 3 . 6 ) ranged from 70 . 3% to 115 . 4%, 69 . 5% to 112 . 6% and 70 . 2% to 116 . 1%spiked at 0. 05 μg/g and 0. 1 μg/g with the relative standard deviations (RSDs, n=6) less than 13. 3%, 13. 5% and 12. 1% in sunflower oil, soybean oil and corn oil samples, respectively. The LODs of this method ranged from 0. 0692 to 2. 28, 0. 0559 to 2. 01 and 0. 0584 to 2. 14μg/kg (S/N=3) in sunflower oil, soybean oil and corn oil samples respectively. The convenient operation and versatility of this method are suitable for the fast screening and detection of 34 pesticide residues in sunflower oil, soybean oil and corn oil.