The separation and identification of the ephedrines(cathine,norephe-drine,ephedrine,pseudoephedrine,methylephedrine and ethylephedrine)and their derivatives obtained from TFAA,MSTFA,MSTFA+MBTFA and MSTFA+Ethyl acetate...The separation and identification of the ephedrines(cathine,norephe-drine,ephedrine,pseudoephedrine,methylephedrine and ethylephedrine)and their derivatives obtained from TFAA,MSTFA,MSTFA+MBTFA and MSTFA+Ethyl acetate deriva- tization were carried out by GC/MSD.展开更多
A GC-MS method for the confirmation of benzthiazide is reported for the first time. This method is based on, the main decomposed product of the methylated derivative and provides a reliable detection of this drug. The...A GC-MS method for the confirmation of benzthiazide is reported for the first time. This method is based on, the main decomposed product of the methylated derivative and provides a reliable detection of this drug. The detection limit of the method is 1.0 ng with selected ion monitoring.展开更多
Objective From the ancient period cow’urine has been used as a medicine. In Veda, cow’urine was compared to the nectar. In Susrut, several medicinal properties of cow’ urine have been mentioned and are known to ca...Objective From the ancient period cow’urine has been used as a medicine. In Veda, cow’urine was compared to the nectar. In Susrut, several medicinal properties of cow’ urine have been mentioned and are known to cause weight loss, reversal of certain cardiac and kidney problems, indigestion, stomach ache, edema, etc. However, the literature and scripture did not mention the antigenotoxic properties of cow’urine. Methods In the present investigation, the antigenotoxic/ antioxidant properties of cow’ urine distillate and redistillate were studied in vitro. The antioxidant status and volatile fatty acid levels were determined. Actinomycin-D (0.1ol/L) and hydrogen peroxide (150 mol/L) were used for inducing DNA strand break with 0.1% DMSO as negative control. Dose for the antigenotoxic effect of cow’ urine was chosen from the dose response study carried out earlier. Results Both actinomycin-D and H2O2 caused statistically significant DNA unwinding of 80% & 75% respectively (P<0.001) as revealed by fluorimetric analysis of DNA unwinding (FADU), and the damage could be protected with the redistilled cow urine distillate (1, 50 & 100 ) in simultaneous treatment with genotoxic chemicals. Conclusion The redistillate of cowurine was found to possess total antioxidant status of around 2.6 mmol, contributed mainly by volatile fatty acids (1500 mg/L) as revealed by the GC-MS studies. These fatty acids and other antioxidants might cause the observed protective effects.展开更多
A new GC/MS method for detection and identification of 19 anabolic steroids in human urine is presented.The procedure involves adsorption and isolation on a macroporous XAD-2 resin,enzymatic hydrolysis,alkaline extrac...A new GC/MS method for detection and identification of 19 anabolic steroids in human urine is presented.The procedure involves adsorption and isolation on a macroporous XAD-2 resin,enzymatic hydrolysis,alkaline extraction,derivatization,GC separation and MS detec- tion.Gas chromatographic-mass spectrometric data illustrate artifacts arising from enzymatic hydrolysis of steroid glucuronides and the structural characterization of their metabolites. Using this method,metabolic studies of these steroids in human urine were made after their ingestion by normal and healthy male volunteers.This method was proven to be suitable for large-scale routine analysis of anabolic steroids and was used successfully in passing the doping control test held by the Medical Commission of the International Olympic Committee.展开更多
A fast screening protocol was developed for the simultaneous determination of nine antiestrogenic agents (aminoglutethimide, anastrozole, clomiphene, drostanolone, formestane, letrozole, mesterolone, tamoxifen, testol...A fast screening protocol was developed for the simultaneous determination of nine antiestrogenic agents (aminoglutethimide, anastrozole, clomiphene, drostanolone, formestane, letrozole, mesterolone, tamoxifen, testolactone) plus five of their metabolites in human urine. After an enzymatic hydrolysis, these compounds can be extracted simultaneously from urine with a simple liquid–liquid extraction at alkaline conditions. The analytes were subsequently analyzed by fast-gas chromatography/ mass spectrometry (fast-GC/MS) after derivatization. The use of a short column, high-fiow carrier gas velocity and fast temperature ramping produced an efficient separation of all analytes in about 4 min, allowing a processing rate of 10 samples/h. The present analytical method was validated according to UNI EN ISO/IEC 17025 guidelines for qualitative methods. The range of investigated parameters included the limit of detection, selectivity, linearity, repeatability, robustness and extraction efficiency. High MSsampling rate, using a benchtop quadrupole mass analyzer, resulted in accurate peak shape definition under both scan and selected ion monitoring modes, and high sensitivity in the latter mode. Therefore, the performances of the method are comparable to the ones obtainable from traditional GC/MS analysis. The method was successfully tested on real samples arising from clinical treatments of hospitalized patients and could profitably be used for clinical studies on anti-estrogenic drug administration.展开更多
尿液在大熊猫化学通讯过程中具有重要作用。对大熊猫尿液中化学成分的检测是揭示大熊猫尿液中化学物质组成及其功能的关键。本实验通过使用顶空固相微萃取技术(Headspace-solid phase microextraction,HS-SPME)对大熊猫尿液样品进行前...尿液在大熊猫化学通讯过程中具有重要作用。对大熊猫尿液中化学成分的检测是揭示大熊猫尿液中化学物质组成及其功能的关键。本实验通过使用顶空固相微萃取技术(Headspace-solid phase microextraction,HS-SPME)对大熊猫尿液样品进行前期处理,继而利用气相色谱-质谱联用技术(Gas chromatography-mass spectrom-etry,GC/MS)对大熊猫尿液中化学成分进行检测。共检测到56个峰,通过在NIST(National Institute of Standards and Technology)质谱库中进行检索,初步推定出其中的38种物质。除此之外,还对HS-SPME萃取头的净化方法进行了探索和改进。结果表明,顶空固相微萃取技术结合气相色谱-质谱联用技术能够应用于大熊猫尿液中挥发性与半挥发性化合物的检测,并且能够得到较好的实验结果,为揭示大熊猫化学通讯机理提供基础。展开更多
文摘The separation and identification of the ephedrines(cathine,norephe-drine,ephedrine,pseudoephedrine,methylephedrine and ethylephedrine)and their derivatives obtained from TFAA,MSTFA,MSTFA+MBTFA and MSTFA+Ethyl acetate deriva- tization were carried out by GC/MSD.
文摘A GC-MS method for the confirmation of benzthiazide is reported for the first time. This method is based on, the main decomposed product of the methylated derivative and provides a reliable detection of this drug. The detection limit of the method is 1.0 ng with selected ion monitoring.
文摘Objective From the ancient period cow’urine has been used as a medicine. In Veda, cow’urine was compared to the nectar. In Susrut, several medicinal properties of cow’ urine have been mentioned and are known to cause weight loss, reversal of certain cardiac and kidney problems, indigestion, stomach ache, edema, etc. However, the literature and scripture did not mention the antigenotoxic properties of cow’urine. Methods In the present investigation, the antigenotoxic/ antioxidant properties of cow’ urine distillate and redistillate were studied in vitro. The antioxidant status and volatile fatty acid levels were determined. Actinomycin-D (0.1ol/L) and hydrogen peroxide (150 mol/L) were used for inducing DNA strand break with 0.1% DMSO as negative control. Dose for the antigenotoxic effect of cow’ urine was chosen from the dose response study carried out earlier. Results Both actinomycin-D and H2O2 caused statistically significant DNA unwinding of 80% & 75% respectively (P<0.001) as revealed by fluorimetric analysis of DNA unwinding (FADU), and the damage could be protected with the redistilled cow urine distillate (1, 50 & 100 ) in simultaneous treatment with genotoxic chemicals. Conclusion The redistillate of cowurine was found to possess total antioxidant status of around 2.6 mmol, contributed mainly by volatile fatty acids (1500 mg/L) as revealed by the GC-MS studies. These fatty acids and other antioxidants might cause the observed protective effects.
文摘A new GC/MS method for detection and identification of 19 anabolic steroids in human urine is presented.The procedure involves adsorption and isolation on a macroporous XAD-2 resin,enzymatic hydrolysis,alkaline extraction,derivatization,GC separation and MS detec- tion.Gas chromatographic-mass spectrometric data illustrate artifacts arising from enzymatic hydrolysis of steroid glucuronides and the structural characterization of their metabolites. Using this method,metabolic studies of these steroids in human urine were made after their ingestion by normal and healthy male volunteers.This method was proven to be suitable for large-scale routine analysis of anabolic steroids and was used successfully in passing the doping control test held by the Medical Commission of the International Olympic Committee.
文摘A fast screening protocol was developed for the simultaneous determination of nine antiestrogenic agents (aminoglutethimide, anastrozole, clomiphene, drostanolone, formestane, letrozole, mesterolone, tamoxifen, testolactone) plus five of their metabolites in human urine. After an enzymatic hydrolysis, these compounds can be extracted simultaneously from urine with a simple liquid–liquid extraction at alkaline conditions. The analytes were subsequently analyzed by fast-gas chromatography/ mass spectrometry (fast-GC/MS) after derivatization. The use of a short column, high-fiow carrier gas velocity and fast temperature ramping produced an efficient separation of all analytes in about 4 min, allowing a processing rate of 10 samples/h. The present analytical method was validated according to UNI EN ISO/IEC 17025 guidelines for qualitative methods. The range of investigated parameters included the limit of detection, selectivity, linearity, repeatability, robustness and extraction efficiency. High MSsampling rate, using a benchtop quadrupole mass analyzer, resulted in accurate peak shape definition under both scan and selected ion monitoring modes, and high sensitivity in the latter mode. Therefore, the performances of the method are comparable to the ones obtainable from traditional GC/MS analysis. The method was successfully tested on real samples arising from clinical treatments of hospitalized patients and could profitably be used for clinical studies on anti-estrogenic drug administration.
文摘尿液在大熊猫化学通讯过程中具有重要作用。对大熊猫尿液中化学成分的检测是揭示大熊猫尿液中化学物质组成及其功能的关键。本实验通过使用顶空固相微萃取技术(Headspace-solid phase microextraction,HS-SPME)对大熊猫尿液样品进行前期处理,继而利用气相色谱-质谱联用技术(Gas chromatography-mass spectrom-etry,GC/MS)对大熊猫尿液中化学成分进行检测。共检测到56个峰,通过在NIST(National Institute of Standards and Technology)质谱库中进行检索,初步推定出其中的38种物质。除此之外,还对HS-SPME萃取头的净化方法进行了探索和改进。结果表明,顶空固相微萃取技术结合气相色谱-质谱联用技术能够应用于大熊猫尿液中挥发性与半挥发性化合物的检测,并且能够得到较好的实验结果,为揭示大熊猫化学通讯机理提供基础。
