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.
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Object To develop a method for the determination of polysaccharide in TIANCI CAPSULE, which is a new drug dosage form containing the bouillon of fresh water mussels with immunopotentiating activity Methods Total polysaccharide was determined by phenol sulfuric acid method with glucose as the standard, and spectrophotometer assay absorbency at 490 nm Results The linear range of polysaccharide was 10～80 ?g/mL, r=0 999 7 The average recovery rate was 98 67% (n=5), RSD=2 58% Through sample assay, the content of polysaccharide was 267 7～300 6 mg in each TIANCI CAPSULE Conclusion The method is simple, rapid and reliable, and may be used for the quality control of this preparation
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Object To optimize the conditions for the extraction of Panax notoginseng (Burk ) F H Chen Methods Conditions for the extraction were studied by orthogonal experimental design as guided by the content of total notoginseng saponin present in the extract Results Significant effect was observed in 3 different experimental conditions Conclusion The optimum condition for the extraction of P notoginseng was to soak the drug in 75% alcohol for 24 h and then percolate at a rate of 1~3 ml/min to collect an amount corresponding to about 10 times of the quantity of P notoginseng
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Object To develop a capillary GC-MS analytical method for identification and deter- mination of ginkgolide A, B, C and bilobalide (GA, GB, GC and BB) in Ginkgo biloba L. leaves. Methods The leave samples were extracted in ultrasonic bath with ethanol-water (20∶80). The extract was purified by liquid-liquid extraction with ethyl acetate followed by solid-phase extraction on a column mixed with acid Al 2O 3, active carbon and celite. The terpenes were trimethylsilylated by BSTFA (with 1% TMCS) for 60 min at 100 ℃ and determined by GC-MS with HP-5 MS capillary column in the selected-ion monitoring mode. The intense fragment ions were chosen as monitoring ions for quantitative analysis. Cholesterol was used as an internal standard. Column temperature gradient: initial temperature 180 ℃, maintained 1 min, and then increased at 20 ℃/min to 260 ℃, and finally at 2 ℃/min up to 300 ℃, maintained 2 min. Results The retention times of GA, GB, GC and BB were 13.7,14.3,15.3 and 6.8 min, the major fragmentation ions (monitoring) were at m/z 537, 625, 713 and 455 (299), the average recoveries of GA, GB, GC and BB were 102.0%, 99.4%, 96.0%, 96.3%, RSD were 0.54%, 2.40%, 1.98% and 2.43%, respectively. Conclusion This method is repeatable, specific, accurate and easy to operate. It is adoptable for quality and quantity analysis of terpene lactones from G. biloba leaves.