ABSTRACT
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.
ABSTRACT
A method was developed for the determination of N-acetyl-S-( N-methylcarbamoyl ) cysteine ( AMCC) in human urine by online solid-phase extraction ( SPE )-high performance liquid chromatography ( HPLC ) . The separation of AMCC from the urine matrix was performed on AmoniPac PA Solid phase Extraction ( SPE ) column with 5 mmol/L KH2 PO4 as the mobile phase by left pump. Then the time was controlled to switch the valve to make only the section of sample containing AMCC transferred into the analytic column-Acclaim PAⅡ C18 . The determination was performed using gradient elution of 0. 1% H3 PO4 (containing 5% acetonitrile) and acetonitrile by right pump. The results showed that AMCC present good linear correlation in the range of 1 . 0-100 mg/L with a correlation coefficient of above 0 . 999 , the quantitation limit of the method was 0. 2 mg/L (with the sample inject volume =10 μL), the recoveries of spiked samples were in the range of 82 . 9%-85 . 9%, and the relative standard deviation ( n=6 ) of retention time and peak area were 0. 2% and 4. 0% respectively. Compared with offline SPE-HPLC, the proposed method was convenient, environmentally friendly, efficient and stable, and feasible for the detection of AMCC in 7 human urine samples.
ABSTRACT
Objective To establish a determining method for the content of berberine hydrochloride in Coptis chinensis Franch.and Xianglian pills.Method The sample was extracted and developed,the berberine hydrochloride was determined by thin layer chromatograph-fluorescence of spectrophotometry with Benzen-ethylaceate-isopropanol-methanol-ammonia water(6:3:1.5:1.5:0.5) as the developing system and Ex=365 nm,Em=409 nm.Result The calibration curve was linear in the range of 0.473～ 3.784 ?g,r=0.999 3.The recovery rate in Coptis chinensis Franch.was 99.03%,RSD=1.86%,and in Xianglian pills was 97.10%,RSD=1.09%.Conclusion The method is simple and accurate.