工作场所空气中二甲醚的气相色谱测定法

目的 建立工作场所空气中的二甲醚含量的采样与检测方法.方法 以溶剂解析型活性炭管采样,四氯化碳解析,采用Elite-WAX色谱柱,柱温箱以40～90℃程序升温,载气从1.4～2.5 ml/min程序递升的方法.结果 二甲醚在0～63.91 μg/ml范围线性关系良好,相关系数为0.999 9,方法检出限为0.75 μg/ml.采样1.5 L,最低检测浓度0.5 mg/m3.结论 该方法精密度和灵敏度较高,可以满足工作场所空气中二甲醚的测定.     

利用微波辅助萃取、电感耦合等离子体质谱和离子色谱联用方法测定生物和环境样品中的重金属以评价其对人体健康的潜在危害

【目的】测定生物和环境样品中的重金属及其化学形态，从而更准确地评价其对人体健康的潜在危害，并且监测重金属从环境基质到人体的迁移途径。【方法】利用微波辅助萃取进行样品预处理，离子色谱分离重金属不同化学形态，电感耦合等离子体质谱进行检测。【结果】微波辅助萃取能够将重金属的不同无机和有机形态从样品基质中有效分离，分离过程中金属形态不发生变化。将离子色谱和电感耦合等离子体质谱在线联用，辅以稳定性同位素标记，可以准确测定生物和环境样品中的金属(铅、铬和汞)形态。【结论】提高生物和环境样品中重金属检测的灵敏度，并且测定金属的化学形态，可以对评价重金属对人体健康的潜在危害提供重要信息。     

Influence of polymorphism on the surface energetics of salmeterol xinafoate crystallized from supercritical fluids

Purpose. To characterize the surface thermodynamic properties of two polymorphic forms (I and II) of salmeterol xinafoate (SX) prepared from supercritical fluids and a commercial micronized SX (form I) sample (MSX). Methods. Inverse gas chromatographic analysis was conducted on the SX samples at 30, 40, 50, and 60°C using the following probes at infinite dilution: nonpolar probes (NPs; alkane C5-C9 series); and polar probes (PPs; i.e., dichloromethane, chloroform, acetone, ethyl acetate, diethyl ether, and tetrahydrofuran). Surface thermodynamic parameters of adsorption and Hansen solubility parameters were calculated from the retention times of the probes. Results. The free energies of adsorption (-G_A) of the three samples obtained at various temperatures follow this order: SX-II > MSX SX-I for the NPs; and SX-II > MSX > SX-I for the PPs. For both NPs and PPs, SX-II exhibits a less negative enthalpy of adsorption (H_A) and a much less negative entropy of adsorption (S_A) than MSX and SX-I, suggesting that the high -G_A of SX-II is contributed by a considerably reduced entropy loss. The dispersive component of surface free energy (_s ^D) is the highest for MSX but the lowest for SX-II at all temperatures studied, whereas the specific component of surface free energy of adsorption (-G_A ^SP) is higher for SX-II than for SX-I. That SX-II displays the highest -G_A for the NP but the lowest _s ^D of all the SX samples may be explained by the additional -G_A change associated with an increased mobility of the probe molecules on the less stable and more disordered SX-II surface. The acid and base parameters, K_A and K_D, that were derived from H_A ^SP reveal significant differences in the relative acid and base properties among the samples. The calculated Hansen solubility parameters (_D, _P, and _H) indicate that the surface of SX-II is the most polar and most energetic of all the three samples in terms of specific interactions (mostly hydrogen bonding). Conclusions. The metastable SX-II polymorph possesses a higher surface free energy, higher surface entropy, and a more polar surface than the stable SX-I polymorph.     

高效液相色谱-电喷雾电离-质谱分析银杏叶中银杏内酯和白果内酯

银杏萜内酯包括银杏内酯和白果内酯是银杏提取物或银杏叶中主要的药效成分。本文用高效液相色谱 -电喷雾电离 -质谱 (HPLC ESI MS)法对银杏叶中银杏内酯和白果内酯进行分析。液相色谱条件为色谱柱为InertsilODS3,流动相为甲醇 -水 (36 :6 4) ,流速 1mL·min- 1 ;质谱为ZMDMicromass电喷雾质谱仪。得到了样品HPLC总离子流和选择离子 (m z 32 5 ,40 7,42 3,439)流图 ,及相应色谱峰的ESI MS质谱图 ,鉴别出银杏叶中白果内酯及银杏内酯A、B、C、J。本方法快捷 ,简便     

气相色谱法测定皮炎平软膏中樟脑和薄荷脑的含量

目的：测定皮炎平软膏中樟脑、薄荷脑的含量。方法：以聚乙二醇为固定相，用氢焰离子化检测器，对樟脑，薄荷脑进行气相色谱定量分析。结果：此法能有效地分离樟脑和薄荷脑并测定其含量。结论：此法准确；专属；精密。     

HPLC法对注射用羟氨苄青霉素钠含量的影响因素测试

利用高效液相色谱法对3个批号，经3000LS强光照射不同时间的注射用羟氨苄青霉素钠进行稳定性测试，结果表明注射用羟氨苄青霉素钠在强光照射下不稳定，含量不断降低，但经3000LS强光照射10天内含量仍均在标准含量80％以上。     

Simultaneous analysis of flunitrazepam and its major metabolites in human plasma by high performance liquid chromatography tandem mass spectrometry

A sensitive and specific high performance liquid chromatography–atmospheric pressure chemical ionization–tandem mass spectrometry (HPLC–APCI–MS–MS) method has been developed for the simultaneous determination of flunitrazepam and its major metabolites, 7-aminoflunitrazepam and N-desmethylflunitrazepam, in human plasma. After the addition of a deuterium labelled internal standard of flunitrazepam, plasma samples were extracted using Oasis® MCX solid phase extraction cartridges. The compounds were separated on a 5 μm Symmetry C18 (Waters) column (3.0×150 mm, i.d.) with a step gradient of acetonitrile-0.1% formic acid at a flow rate of 0.6 ml/min. The overall extraction efficiency was more than 89% for all three compounds. The limits of detection were 0.25 g/l for flunitrazepam, 0.5 μg/l for 7-aminoflunitrazepam, and 2.0 μg/l for N-desmethylflunitrazepam. Within-run accuracies for quality-control samples were between 92.5 and 101.3% of the target concentration, with coefficients of variation <8%. The proposed method enables the unambiguous identification and quantitation of flunitrazepam and its major metabolites in both clinical and forensic specimens.     

Determination of ethylenediamine tetraacetic acid in injection forms by ion-pair chromatography

A high performance liquid chromatographic method was developed for the determination of ethylenediamine tetraacetic acid (EDTA) in injection forms. The method consists of direct extraction of the samples with ethyl acetate; the organic layers were evaporated to dryness and further diluted to a 0.025% (w/v) copper nitrate in order to achive the formation of the EDTA–copper solution complex. The chromatographic separation was performed on a C8 Hypersil column. The mobile phase consisted of a mixture of acetonitrile–0.015 M tetrabutylammonium hydroxide (10:90, v/v), (pH* 7.0) pumped at a flow rate of 1.5 ml min⁻¹. The UV detector was operated at 300 nm. Correlation coefficients of the calibration graphs were better than 0.9995, relative standard deviation was less than 2.5%. Detection limit of EDTA was found to be 1.97 μg ml⁻¹.     

高效液相色谱法测定大鼠脑和NG108-15细胞内胍丁胺含量(英文)

目的　建立测定大鼠不同脑区和NG10 8 15细胞内源性胍丁胺含量的方法。方法　用高效液相色谱荧光检测法测定大鼠不同脑区 (包括皮层、海马、丘脑、纹状体和小脑 )及NG10 8 15细胞内胍丁胺含量。结果　正常大鼠不同脑区胍丁胺的含量范围为 0 .8～ 1.71μg·g- 1湿脑组织 ;NG10 8 15细胞内含量为 0 .0 4 4mg·g- 1蛋白。结论　此法适于常规测定动物脑组织及培养细胞内的胍丁胺含量。     

Reverse geometrical selectivity in glucuronidation and sulfation of cis- and trans-4-hydroxytamoxifens by human liver UDP-glucuronosyltransferases and sulfotransferases

The phenolic active metabolites, cis-4-hydroxytamoxifen (cis-HO-TAM) and trans-4-hydroxytamoxifen (trans-HO-TAM), of the anti-breast-cancer drug, trans-tamoxifen (TAM), were geometrically selectively glucuronidated in the manner of cis>trans by microsomes and sulfated in the manner of trans>cis by cytosol from the liver of 10 human subjects (7 females and 3 males). There was a large individual difference in the microsomal glucuronidation of cis-HO-TAM, which correlated well with glucuronidation of 4-hydroxybiphenyl by human liver microsomes. However, there was only a slight correlation between the glucuronidation of cis-HO-TAM and trans-HO-TAM or 4-nitrophenol (NP). A small individual difference was observed for the human liver cytosolic sulfation of trans-HO-TAM, which correlated well with the sulfation of NP. Recombinant human UDP-glucuronosyltransferase (UGT)2B15 catalyzed the cis-selective glucuronidation of geometrical isomers of HO-TAM. UGTs1A1, 1A4, 1A9 and 2B7 had weak activity toward HO-TAMs with a much smaller cis-selectivity than did UGT2B15. UGTs1A3 and 1A6 had no detectable activity toward these substrates. Among the four known major sulfotransferases (SULTs) occurring in the human liver, SULT1A1 was strongly suggested to play the most important role in the hepatic cytosolic trans-selective sulfation of HO-TAM isomers. A good correlation was observed between the hepatic cytosolic sulfation of trans-HO-TAM and NP, a standard substrate for SULT1A1. SULT1E1 had slight activity toward the HO-TAMs. SULTs1A3 and 2A1 had no detectable activity toward HO-TAMs.