柱前衍生化RP-HPLC法分析龟板中氨基酸

目的采用柱前衍生RP-HPLC法对龟板中13种氨基酸进行分析。方法用6mol/L HCl水解提取龟板中总氨基酸,以异硫氰酸苯酯(PITC)为柱前衍生化试剂,采用外标法,梯度洗脱的方式分析。结果13种氨基酸在40min内均可得到很好的分离,回收率(除甘氨酸外)为91.68%~106.26%,RSD为0.718%~4.386%。结论所建立的方法分离效果好、灵敏、准确、简便,且采用普通的C18色谱柱,可广泛用于含有多种氨基酸样品的分析。     

HPLC法同时测定21种中药饮片中4种黄曲霉毒素的含量

目的:对21种中药饮片中的黄曲霉毒素B1、B2、G1、G2进行含量测定,了解中药饮片的质量状况。方法:采用高效液相色谱(HPLC)-柱后碘衍生法进行含量测定,Waters Sunfire C18色谱柱(4.6 mm×250 mm,5μm),柱温35℃,以甲醇-乙腈-水(33∶12∶55)为流动相,流速1.0 mL/min。荧光检测器激发波长λex=360 nm,发射波长λem=450 nm。以0.05%碘溶液为衍生溶液,衍生化泵流速为0.3 mL/min,衍生化温度为70℃。结果:21种中药饮片中,只有胖大海、酸枣仁、大枣、全蝎、淡豆豉、牛蒡子、千金子7个品种未检出黄曲霉毒素;4批柏子仁、6批薏苡仁全部检出黄曲霉毒素,检出率均为100%,其中3批柏子仁的黄曲霉毒素含量超出法定标准限量,不合格率75%;2批薏苡仁的黄曲霉毒素含量超出法定标准限量,不合格率33%。桃仁、陈皮等其余12个品种亦检出黄曲霉毒素,但含量未超出法定标准限度。结论:虽然黄曲霉毒素检测成本较高,但为保证用药安全、减少用药风险,对中药饮片进行合理的黄曲霉毒素监督检测具有必要性。     

柱前衍生HPLC-UV同时测定人工牛黄中胆酸及猪去氧胆酸的含量

目的建立柱前衍生HPLC-UV同时测定人工牛黄中胆酸及猪去氧胆酸的含量。方法以2-萘基溴甲基酮为衍生试剂,三乙胺为催化剂,60℃水浴条件下对胆酸及猪去氧胆酸进行衍生,考察衍生试剂用量、催化剂用量及反应时间等对衍生产物的影响,确定衍生反应的条件,然后考察建立HPLC-UV分离检测方法对人工牛黄中胆酸及猪去氧胆酸含量进行测定。结果当衍生试剂的摩尔量与胆酸及猪去氧胆酸的摩尔总量的比大于30∶1,催化剂的摩尔量与两者的摩尔总量的比在5∶1~60∶1范围内,在60℃水浴条件下反应50 min时,胆酸及猪去氧胆酸的衍生物反应完全。方法学验证:胆酸在0.4~5.0μg范围内线性关系良好(r=0.999 5);猪去氧胆酸在0.12~1.5μg范围内线性关系良好(r=0.999 8)。胆酸的平均回收率(n=6)为100%,RSD为2.40%;猪去氧胆酸的平均回收率(n=6)为101%,RSD为1.33%。此批次人工牛黄样品中胆酸的含量为5.55%,猪去氧胆酸的含量为2.55%。结论本方法灵敏度高、准确可靠、稳定性和重复性好,可用于测定人工牛黄中胆酸及猪去氧胆酸的含量。     

A TLC fluorescence derivatization assay for chlorpromazine and its non-conjugated hepatic microsomal metabolites

Procedures for the assay of chlorpromazine (CPZ) and its metabolites were compared. An improved assay, involving organic extraction, thin-layer chromatography and fluorescence derivatization, was developed. The compounds were extracted from microsomal protein suspensions into 15% n-propanol in dichloromethane by successive extractions at pH 2 and pH 12. CPZ and its mono- and di-desmethyl, 7-hydroxy, N-oxide, sulphoxide and N-oxide-sulphoxide metabolites were separated using TLC on silica gel developed with methanol-acetone-ammonia (50:50:1 v/v/v). The compounds were extracted from the TLC plate with chloroform-methanol (2:1 v/v) and subjected to oxidation with hydrogen peroxide. The highly fluorescent oxidized derivatives were identified as sulphoxides by their fluorescence characteristics. Amounts of derivatized CPZ and metabolites were measured using derivatized promazine as the internal standard.     

Human exposure to styrene

Summary The derivatization of phenylglyoxylic acid (PGA), a urinary styrene metabolite, gives with diazomethane under ordinary reaction conditions secondary products as expected from the behaviour of other -keto acids. Thus reproducible quantitative analysis becomes difficult. It is shown that by proper selection of reaction conditions (low temperature, short reaction time) these secondary transformations can be inhibited and exclusive derivatization to the methylester is obtained. A quantitative determination of urinary PGA can be based on this derivatization procedure. However, this method is not considered suitable for routine monitoring due to the delicate reaction conditions necessary. The results are discussed with reference to a recently published procedure based on an unknown derivative of PGA.     

Liquid chromatography–mass spectrometry behavior of Girard's reagent T derivatives of oxosteroid intact phase II metabolites for doping control purposes

Intact phase II steroid metabolites have poor product ion mass spectra under collision-induced dissociation (CID) conditions. Therefore, we present herein the liquid chromatography–electrospray ionization–tandem mass spectrometry (LC–ESI–MS/(MS)) behavior of intact phase II metabolites of oxosteroids after derivatization. Based on the fact that Girard's reagent T (GRT), as derivatization reagent, was both convenient and efficient in terms of the enhancement in the ionization efficiency and the production of diagnostic product ions related to the steroid moiety, the latter was preferably selected between methoxamine and hydroxylamine upon the model compounds of androsterone glucuronide and androsterone sulfate. Sixteen different glucuronides and 29 sulfate conjugated metabolites of anabolic androgenic steroids (AASs), available either as pure reference materials or synthesized/extracted from administration studies, were derivatized with GRT, and their product ion spectra are presented. Product ion spectra include in all cases high number of product ions that in some cases are characteristic for certain structures of the steroid backbone. More specifically, preliminary results have shown major differences in fragmentation pattern for 17α/17β-isomers of the sulfate conjugates, but limited differentiation for 17α/17β-isomers of glucuronide conjugates and for 3α/3β- and 5α/5β-stereoisomers of both sulfate and glucuronide conjugates. Further to the suggestion of the current work, application on mesterolone administration studies confirmed—according to the World Anti-Doping Agency (WADA) TD2015IDCR—the presence of seven intact phase II metabolites, one glucuronide and six sulfates with use of LC–ESI–MS/(MS).     

肺痹病因病机认识的衍化

论述了肺痹病因病机在不同历史时期的发展特点。肺痹病因病机理论以《内经》为源,为五脏痹之一,后世阐发多宗于此;两晋隋唐时期,医家多从气极论述肺痹,并强调脏腑内虚在肺痹发生发展的作用;宋金元时期,发挥了《内经》多种肺痹病因病机的理论,强调其虚劳性特点;明清两代,除了继承前代理论外,温病医家对肺痹病因病机的理论有了新的发展,或以肺痹为肺气痹阻,或以其为病机一环,扩大了肺痹的外延。      

一种新的柱前衍生法测定血浆同型半胱氨酸

目的建立一种新的高效液相柱前衍生法,准确、快速测定血浆同型半胱氨酸(HCY)浓度.方法血中结合态的HCY经三丁基膦还原为游离HCY后,与衍生试剂7-氟苯唑-2-氧-1,3-二唑-4-磺酸胺(ABD-F)进行柱前衍生反应,衍生物经反相C18色谱柱,用0.15mol/L磷酸盐缓冲液(pH=4.2)与甲醇按85∶15配制的混合液洗脱.荧光检测激发λ=385nm,发射λ=515nm.结果在3.125～100.00μmol/L范围内,HCY浓度与荧光强度的线性关系良好,γ=0.9998,测定的批内、批间变异系数分别为3.13%和5.10%,高低2种浓度的回收率分别为98.5%和92.7%,健康人血浆HCY的参考值为8.12±2.72μmol/L.结论本法测定血浆HCY准确快速、特异性高、分离效果好,适用于临床血浆HCY测定的常规需要.     

Analysis of amphetamine,methamphetamine, methylenedioxyamphetamine and methylenedioxymethamphetamine in whole blood using in-matrix ethyl chloroformate derivatization and automated headspace solid-phase microextraction followed by GC-MS

The in-matrix alkyl chloroformate derivatization method for amphetamine, methamphetamine, methylenedioxyamphetamine (MDA), and methylene-dioxymethamphetamine (MDMA) was adapted for use with the whole blood matrix. This derivatization method was followed by automated headspace (HS)-solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) analysis. The sensitivity of this method, expressed as limit of detection, was approximately 10 ng/ml for these analytes tested in the blood matrix, which was sufficient to detect toxic concentrations of amphetamines in blood. The limit of quantitation for target analytes ranged from 0.05 to 0.2 μg/ml. The intraday precision and accuracy studies generally showed satisfactory results for all target compounds except MDA, in which a larger variation was observed. The in-matrix ethyl chloroformate derivatization of amphetamine, methamphetamine, MDA, and MDMA for HS-SPME was tested in other matrices such as stomach fluid, bile, thoracic cavity fluid, vitreous humor, brain, liver, spleen, and skeletal muscle. As a result, stomach fluid, thoracic cavity fluid, and vitreous humor showed SPME efficiencies higher than that of whole blood; however, this method was not suitable for solid tissue matrices under the present conditions.     

指纹图谱技术评价不同干燥方式对地龙氨基酸组分提取物的影响

目的 对不同干燥方式所得地龙氨基酸组分提取物进行指纹图谱测定方法的研究, 比较不同干燥方式对地龙氨基酸组分提取物品质的影响。方法 采用异硫氰酸苯酯柱前衍生化反相高效液相色谱法, 测定并比较真空冷冻干燥、真空减压干燥和微波干燥3种方式所得地龙干燥样品以及未经干燥样品的指纹图谱, 以中药色谱指纹图谱相似度评价系统计算相似度, 并进行图谱比较和指认分析。结果 建立了不同干燥技术处理的地龙氨基酸组分提取物高效液相指纹图谱, 确定了17个共有峰, 同一干燥方法不同批次干燥产品的镜像度较高, 具有良好的相似性(>0.9), 不同干燥方法所得提取物之间有较大的质量差异。结论 HPLC指纹图谱分析法可较全面的反映不同干燥技术处理的地龙氨基酸组分提取物间的差异, 可用于同类提取物干燥工艺的质量控制和工艺评价。冷冻干燥法是地龙氨基酸组分提取物最适宜的干燥方法。