A New Procedure for the Extraction of Unconjugated Steroids from Plasma and Urine

Abstract

A procedure is described for the extraction of nanogram quantities of steroids from plasma and urine. The method involves saturation of a diluted plasma or urine sample with ammonium carbonate and extraction with an organic solvent. The application of this method to the analysis of cortisol and unconjugated estriol in plasma and to the analysis of unconjugated steroids in the urine of the newborn infant is described.     

Improved Apparatus for Celite Chromatography of Steroids

Abstract

A valve arrangement is described which can be incorporated into an apparatus previously designed for the simultaneous operation of large numbers of celite micro columns during the chromatographic separation of steroids. Compared to previous designs this modification reduces the total elution time of solvents from the column, renders the whole procedure less laborious and has the additional advantage of enabling the introduction of solvents into the chromatography column without disturbing the connection to the pressure supply.     

A Novel Liquid-Gel Chromatographic Method for Extraction of Unconjugated Steroids from Aqueous Solutions

Abstract

Unconjugated steroids of low and medium polarity can be essentially quantitatively extracted from aqueous solutions by rapid filtration through a small column of Lipidex 1000. Forty ml of urine can be extracted by a 4 ml column bed at a flow rate of 5 ml/ min. Less polar steroids (progesterone, testosterone) can be extracted directly, whereas 5% pentylamine has to be added to the aqueous solution to give a quantitative extraction of cortisol. The same method can be used for extraction of steroids in plasma. It is suggested that this method may be generally applicable to the extraction from biological fluids of compounds with a polarity similar to or lower than that of steroids.     

疏水条件下甾体化合物的分离及环糊精的作用

分别应用胶束电动毛细管色谱法（ＭＥＣＣ）、反相色谱法和串联柱ＨＰＬＣ法分离 左旋十八甲基炔诺酮（ＬＮＧ）、睾酮（Ｔ）、孕酮（Ｐ－雌二醇（Ｅ２）等甾体化合物ＭＥＣＣ分离在未涂层毛细管柱上进行。当电泳缓冲溶液为含２０ｍｍｏｌ／Ｌ的２,６－二甲基－β环糊精（（ＤＭ－β－ＣＤ）添加剂和５０ｍｍｏｌ／Ｌ的十二烷基硫酸钠（ＳＤＳ）的１０ｍｍｏ／Ｌ四硼酸钠（ＰＨ９．２）时,可实现快速分离。通过与反相色谱法和串联     

Chromatographic Purification of Tritiated Steroids Prior to Use in Radioimmunoassay

Abstract

The purity of tritiated steroids used as reagents in radio immunoassay plays an important role in the reliability of the assay. These radioactive reagents should be assessed for purity upon receipt and the purity should be checked periodically afterward. For such purposes, we have used chromatographic purification on Celite microcolumns. By charging the polarity of the stationary and mobile phases, 20 different tritiated steroids with a wide range of polarity could be purified on these microcolumns. This approach is easy, rapid, economical, and reliable.     

间乙炔基苯偶氮线性酚醛泡沫的结构与性能研究

采用高温化学发泡法制备了一种间乙炔基苯偶氮酚醛树脂泡沫(EPANF).采用傅里叶红外光谱(FTIR)、凝胶渗透色谱(GPC)、光学显微镜、扫描电子显微镜(SEM)、导热系数分析仪、临界氧指数分析仪和热重分析(TG)等表征了间乙炔基苯偶氮酚醛树脂(EPAN)结构和EPANF的泡孔结构、压缩强度、隔热性能、阻燃性能和热性能.研究结果表明,当所用发泡剂含量为18%,泡沫体的表观密度为0.179 g/cm~3时,EPANF泡孔均匀微细,闭孔率高,泡孔平均粒径为350μm左右.随着表观密度增加,泡沫体压缩强度增大,热导率系数增大,隔热性能略有下降,但其临界氧指数变大,阻燃性能提高.当表观密度为0.363 g/cm~3时,EPANF的压缩强度达到最大为5.63 MPa.EPANF的5%和10%热失重温度分别为333、381℃,其700℃的残炭率和1000℃的残炭率分别为65.8%和58.2%,耐热性和耐烧蚀性较普通线性酚醛树脂有明显提高.EPANF作为热结构材料和烧蚀材料有望在航天航空等领域应用.     

Determination of Steroids in Human Urine by Micellar Liquid Chromatography

Abstract

A simple and sensitive method for the determination of steroids using micellar liquid chromatography is described. The steroids, including hydroxycorticosterone. corticosterone, northisterone, testosterone, mexdroprogesterone acetate and progesterone, were separated by reversed-phase using a micelles mobile phase following UV detection at 245 nm. The parameters affecting retention of the test solutes such as the concentration of sodium dodecyl sulfate (SDS) and n-butanol-1 in the mobile phase were investigated. It was found that the retention of the solutes was dependent on the composition of mobile phase. The linear calibration plots range from 0.1 to 10 μg ml^?1 in mobile phase containing 5.0 × 10^?2 mol l^?1 SDS/9 % n-butanol-1 at pH 6.0, and the detection limit in order of 0.1 μg ml^?1 was obtained. The proposed method was used for the determination of steroids in urine using direct injection of samples without previous treatment.     

液相色谱-串联质谱法测定头发中10种蛋白同化激素

建立了同时测定头发中10种蛋白同化激素液相色谱-串联质谱(LC/MS/MS)分析方法。头发样品经NaOH消解、戊烷液液提取后,用反相液相色谱分离,电喷雾正离子源进行离子化,用多反应监测方式(MRM)对这10种蛋白同化激素的母离子及子离子进行监测,三重四极杆质谱测定。10种蛋白同化激素的检出限为1~20ng/g;相对标准偏差(RSD)为1.72%~13.77%;回收率为38.20%~110.38%;线性回归系数(R2)为0.9958~0.9999。本方法简便快速、灵敏度高、专属性强,可满足在兴奋剂检测或毒物分析中对毛发中蛋白同化激素测定的要求。     

尿中二氯苯异构体的气相色谱/质谱法分析

应用顶空固相微萃取法提取尿中邻、间、对位二本。０．５ｍＬ检尿密封在１２ｍＬ玻璃瓶中,３０℃下用１００μｍ聚二甲基硅氧烷萃取头萃取１５ｍｉｎ。用重氢对二甲苯作内标。选择离子监测ｍｌｚ１４６（二氯苯异构体）和ｍｌｚ１１６（内标）两分子离子峰。以得取的上述两峰面积之比为纵坐标,以二氯苯异构体的浓度为横坐标做校正曲线。尿中检测浓度可达０．０１ｍｇ／Ｌ。用此方法快速准确地测定了二氯苯中毒患者尿中浓度的经时变     

A Simplified Neutron Activation Analysis Method for Copper and Manganese

Abstract

An activation analysis procedure has been developed to determine manganese and copper serum values in one milliliter of serum or less rapidly and with good precision. The sample is irradiated in a neutron flux of 10¹²cm^?2 sec^?1 for two hours followed by nitric acid digestion. The activity plus carrier is absorbed from saturated lithium chloride solution on Dowexl-8 contained in a syringe. After washing the resin with more lithium chloride, the syringe is counted in a five inch well crystal multichannel spectrometer. The carrier is washed off the syringe by dilute acid and analyzed. The sample concentration is determined by comparison to irradiated standards correcting the unknown for decay and chemical yield.     

A Simplified Method for the Separation of Steroid Hormones and Its Application to Radioligand Assays

Abstract

A simplified method for separating the major progestogens, estrogens and androgens in plasma was developed for use in both competitive protein binding assays (CPBA) and radioimmunoassays (RIA). The method, based on liquid-liquid partition chromatography, utilizes microcolumns consisting of plastic disposable syringes packed with celite:ethylene glycol. The method was applied to the plasma measurement of progesterone by CPBA and estradiol and testosterone by RIA.     

Uses of Chloromethyldimethylsilyl Ethers as Derivatives for Combined Gas Chromatography-Mass Spectrometry of Steroids

Abstract

Chloromethyldimethylsilyl (CMDMS) ethers are useful derivatives for combined gas chromatography-mass spectrometry. They have characteristically longer retention times than the corresponding trimethylsilyl (TMS) derivatives, and this permits effective fractionation of mono-, di-, and trihydroxy steroids. CMDMS ethers provide mass spectra comparable with those of TMS ethers, but ions containing the CMDMS group are readily recognisable in the former by virtue of the two abundant natural isotopes of chlorine. This facilitates interpretation of spectra and may be expected to aid the location of drug metabolites by selective ion monitoring.     

Optimization of the Extraction and Analysis of Natural Androgen Steroids and Their Metabolites in Urine by GC/MS and GC/FID

A multiresidue method was developed for screening, quantification, and confirmation of nine natural androgen steroids and their metabolites in urine. Steroids were first extracted from urine by solid phase extraction, enzymatically deglucuronated, re-extracted using a liquid/liquid extraction for purification, and finally acetylated for GC/MS and GC/FID analysis. Each step of sample preparation, as well as analysis, was optimized: solid phase extraction, liquid/ liquid extraction, and derivatization reaction … Therefore, a rugged sample preparation procedure was developed leading to extracts of sufficient purity (recoveries >66% and few matrix compounds). The whole methodology allowed reliable detection and quantification of the nine steroids at low concentration levels. Linearity and repeatability were established and were found to be satisfactory (R² > 0.996, RSD < 11%). Finally, the method was applied to quantify compounds of interest in real samples collected from healthy volunteers and patients treated with 4-androstenedione or dehydroepiandrosterone.     

动物尿液中15种甾类同化激素的液相色谱-串联质谱同时测定

采用液相色谱-电喷雾串联质谱仪（LC-ESIMS/MS）,在多反应监测（MRM）模式下建立了动物尿液中15种甾类同化激素（睾酮、孕酮、诺龙、甲基睾酮、丙酸睾酮、丙酸诺龙、苯丙酸诺龙、大力补、勃地龙、群勃龙、康力龙、醋酸群勃龙、甲炔诺酮、甲羟孕酮、醋酸甲羟孕酮）的快速确证测定方法。试样经酶解处理后,过C18固相萃取柱净化,氮吹至干,残余物用0.50 mL乙腈-水（体积比1∶1）溶解后测定。采用正离子扫描方式进行仪器方法学研究,确定监测离子对,进行MRM模式定性定量分析。该方法的检出限（LOD）为0.2～0.5μg/L,定量下限（LOQ）为0.5～1.0μg/L;在2.0～200.0μg/L范围内线性关系良好,相关系数均大于0.998。在1.0、5.0μg/L的添加水平上,上述15种激素的平均回收率为59%～118%,相对标准偏差为1.0%～11.2%。该法操作简单,灵敏度高,可用于动物尿液中15种甾类同化激素的测定。     

A Simple Liquid Chromatography Method for the Determination of Captopril in Urine

A simple and specific method for the determination of total captopril in human urine was developed. 2-Chloro-1-methylquinolinium tetrafluoroborate was used as a thiol precolumn derivatizing reagent after conversion of a disulfide forms to free captopril with tris(2-carboxyethyl)phosphine hydrochloride. The 2-S-quinolinium derivative of captopril was separated on a Zorbax SB C-18 column using reversed-phase ion-paring chromatography and monitored by spectrophotometric detector at 355 nm. The calibration curve for the derivatized captopril showed linearity in the range 0.1–200 μmol L⁻¹ of urine with a regression coefficient corresponding to 0.9999. The detection and quantitation limits were 0.05 and 0.1 μmol L⁻¹, respectively. The intra-day imprecision was from 0.01 to 10.58%. This method can be used for routine clinical monitoring of the thiol-drug. Omission of the reduction step gives result for concentration of the reduced form of captopril.     

蛋白同化激素类兴奋剂质谱法检测的现状和发展

对蛋白同化激素类兴奋剂检测的发展和现状进行了评述，除目前常规的色谱／色谱联用选择离子检测方法外，强调指出了高分辨质谱和串联质谱的应用前景。     

Serial Hydrolysis for the Simultaneous Analysis of Catecholamines and Steroids in the Urine of Patients with Alopecia Areata

Catecholamines and steroids are well-known neurotransmitters and hormones that rapidly change the excitability of neurons. Alopecia areata is a disease for which the exact cause is unknown, but it is considered to be associated with stress, and so the simultaneous analysis of catecholamines and steroids is required for the diagnosis of alopecia areata. Thus, we herein report the simultaneous analysis of catecholamines and steroids bearing different functional groups for the first time, during which it was necessary to carry out a serial hydrolysis procedure. Following hydrolysis of the urine samples to produce the free forms from the urinary conjugates, ethyl acetate extractions were carried out, and chemical derivatization was performed using dansyl chloride to increase the sensitivity of the liquid chromatography–tandem mass spectrometry method. The matrix effects and recoveries of this analytical method were validated, giving values of 85.4–122.9% and 88.8–123.0%, respectively. In addition, the method accuracy and precision were assessed, giving values of 0.4–21.5% and 2.0–21.6% for the intra-day and inter-day precisions, respectively. This validated method was then applied to identify differences between patients with and without alopecia areata, wherein the metanephrine content was found to be significantly higher in the alopecia areata patient group. This quantitative profiling method can also be applied to steroid-dependent diseases, as well as catecholamine-related diseases.     

Determination of Aromatic Amines in Urine using Extraction and Chromatographic Analysis: A Minireview

Abstract

Aromatic amines found in tobacco smoke are carcinogenic to humans. There are no doubts that they cause of cancers in the lungs, bladder, kidneys, pancreas, esophagus, larynx, pharynx, and oral cavities associated with public health. Therefore, monitoring, control, and awareness toward the smoking effects are important subjects to be conveyed. Thus, rapid, sensitive, simple and accurate analytical methods for the identification of aromatic amines and their metabolites are required to provide a clear and complete visualization for the occurrence of aromatic amines by investigating the urine of smokers and nonsmokers. This comprehensive review serves to give an overview of the previous and recent studies about the analytical trends for the determination of urinary aromatic amines. This review covers the sampling methodologies and sample preparation techniques such as solvent extraction, solid phase extraction, magnetic solid phase extraction, and solid phase microextraction couple with different separation methods including gas chromatography and liquid chromatography. To add more value to this review paper, the advantages, disadvantages, challenges, and the future prospects of these methods are discussed as well. This review is hopefully beneficial for researchers to access and monitor the level of potentially carcinogenic aromatic amines in human urine.     

On the Reaction between Alkyl Isocyanides and Ethynyl Phenyl Ketone in the Presence of N,N′-Dimethylbarbituric Acid

Summary.  The reactive 1:1 intermediate produced in the reaction between alkyl isocyanides and ethynyl phenyl ketone was trapped with N,N ′-dimethylbarbituric acid to produce alkyl 1,3-dimethyl-2,4-dioxo-7-phenyl-1,3,4,5-tetrahydro-2H-pyrano[2,3-d]pyrimidine-5-carboxamides in good yields. Corresponding author. E-mail: isayavar@yahoo.com Received January 8, 2002. Accepted January 14, 2002