海洛因毒品水解机理的探讨

利用海洛因在氯仿和乙醚中溶解性的差异,在pH 4.4~11.9范围内,对收缴海洛因毒品分别采用氯仿和乙醚进行提取和检测,以研究海洛因毒品可能存在的变化规律。实验表明,当pH值小于9.22时,水溶液中海洛因变化是以酸碱中和反应为主,水解反应为辅;当pH值大于9.22时,海洛因完全转化为海洛因碱,随着pH值的增加,海洛因碱进入快速水解状态,分解产物为单乙酰吗啡和吗啡。该研究可为海洛因收缴毒品的提取、检测以及制备海洛因碱等方面提供参考。     

海洛因滥用者毛发中毒品代谢物的固相萃取-GC/MS分析

考察了采用固相萃取技术时毛发中海洛因毒品及其代谢物的原形释放方法。通过对海洛因吸食者毛发和空白添加标准品毛发的碱消解、酸消解、甲醇超声提取、甲醇-5 mol/L HCI超声提取、甲醇-TFA超声提取5种毛发中毒品及其代谢物的释放方法考察,确立了甲醇超声提取-固相萃取-气相色谱/质谱-选择离子检测的方法为稳定、有效的海洛因滥用者毛发中毒品及其代谢物的释放与检测方法。利用该方法对添加6-单乙酰吗啡的毛发进行萃取和测试,6-单乙酰吗啡的回收率为78.7%,相对标准偏差RSD为2.4%,该方法可有效地检出海洛因滥用者毛发中的6-单乙酰吗啡。     

Capillary Electrophoretic Analysis of Common Illicit Drugs

系统地研究了毛细管电泳分析中各种因素对常见毒品混合物分析的影响,用均匀设计确定了适用几类毒品分离分析的最佳电泳条件。 并采用固相提取技术、毛细管区带电泳检测方法对血和尿生物检材中的冰毒、 吗啡、 单乙酰吗啡、 可待因、 海洛因等毒品进行了测定。 通过对各种提取剂回收率的测定, 认为GDX301和反相C18提取效果较好; 并考察了几种毒品的线性关系、 最小检测量等, 为体内毒品分析提供了一些可借鉴的数据。     

常见毒品的毛细管电泳分析

系统地研究了毛细管电泳分析中各种因素对常见毒品混合物分析的影响，用均匀设计确定了适用几类毒品分离分析的最佳电泳条件。并采用固相提取技术、毛细管区带电泳检测方法对血和尿生物检材中的冰毒、吗啡、单乙酰吗啡、可待因、海洛因等毒品进行了测定。通过对各种提取剂回收率的测定，认为ＧＤＸ３０１和反相Ｃ１８提取效果较好；并考察了几种毒品的线性关系、最小检测量等，为体内毒品分析提供了一些可借鉴的数据     

亲水模式下流动相pH值对磷酸化肽在Click OEG-CD材料上富集选择性的影响

以标准蛋白质α-酪蛋白的酶解液作为研究对象,考察流动相pH值对磷酸化肽在Click OEG-CD材料上富集选择性的影响。首先以磷酸苯二钠作为模型化合物考察流动相pH值对其在Click OEG-CD材料上的保留影响,结果表明当pH值低于磷酸根的pK_a值时,磷酸苯二钠难以电离,与材料的离子交换作用较弱,因而保留也较弱。然后在亲水模式下流动相pH值分别为2, 4, 6时考察Click OEG-CD材料对α-酪蛋白的酶解液中磷酸化肽的富集选择性影响。结果表明,当流动相pH为2时,磷酸化肽不能被材料富集;当pH为4时,磷酸化肽能够被富集,而且洗脱窗口较窄;当pH为6时,磷酸化肽也能够被富集,但是洗脱窗口较宽。因此适合亲水模式下富集磷酸化肽的流动相pH值为4。本研究结果能够为今后将Click OEG-CD材料更好的应用于磷酸化肽富集提供有意义的借鉴。     

毛发中海洛因代谢物的释放与分析方法研究

通过对海洛因吸食者毛发和空白添加标准品毛发的碱消解、酸消解、甲醇超声提取、甲醇-5 mol/L HCl超声提取、甲醇-三氟乙酸超声提取5种毛发中毒品及其代谢物的释放方法考察,确立了甲醇超声提取-液液萃取-气相色谱/质谱-选择离子检测的方法.本方法可最大程度地抑制海洛因的中间代谢物6-单乙酰吗啡的水解,其水解率仅为2.63%,极大地提高了海洛因滥用的毛发证据作用.利用本方法对添加6-单乙酰吗啡的毛发进行萃取和检测,6-单乙酰吗啡的回收率为52.6%,相对标准偏差RSD为4.6% ;对添加不同浓度的吗啡、可待因、6-单乙酰吗啡3种毒品的毛发进行萃取和检测,其线性良好(r＞0.99),相对标准偏差均小于15%.此外,考察了甲醇消解的影响因素,吸毒者毛发中的毒品释放效果随毛发的细碎程度和超声时间延长而提高.     

整体柱电渗泵的流量控制研究

通过制备丙烯酸酯类整体柱电渗泵,在nL/s～μL/s级流量范围内,考察了操作电压、有机调节剂浓度、盐浓度、pH值等对流量的影响.实验结果表明,在3～17 kV范围内,操作电压与流量呈线性关系,线性相关系数达到0.9991;当选择乙腈(0.55～0.8 mmol/L浓度范围)与MES缓冲溶液混合作为输运溶液时,电渗泵流量随有机调节剂浓度增加而呈减小趋势,且当盐浓度在0.5～2.0 mmol/L范围内逐渐增加时,电渗泵流量逐渐减小;pH值在3～9时,电渗泵流量基本不变.结果表明, 丙烯酸酯类整体柱电渗泵较ODS柱电渗泵具有一定优势.     

表阿霉素及其相关物质在反相离子对色谱中的色谱行为

以表阿霉素及其6种相关物质为研究对象,系统评价了其在反相离子对色谱模式下的色谱行为.分别考察了流动相中有机相种类、有机相比例、水相中离子对试剂浓度、pH值对表阿霉素及其相关物质的影响.结果表明,使用乙腈作为有机相洗脱能力及分离效果优于甲醇,保留时间随乙腈比例增大而减小;随着离子对试剂十二烷基硫酸钠浓度增加,杂质阿霉素酮及柔红霉酮几乎无影响,其他5种物质保留时间增加.同时,表阿霉素及其杂质的保留行为受流动相pH值影响较大,当pH不高于4时可获得较好的分离效果.通过对表阿霉素及其相关物质反相离子对模式下的保留行为进行了系统的评价和定量描述,研究结果将有助于该类化合物液相色谱分离方法的发展.     

A3钢在缓蚀颜料提取液中的EIS研究

应用EIS研究了A3钢在不同 pH值的磷酸锌或三聚磷酸铝 3.5 %NaCl提取液中的腐蚀行为 .结果显示 ,相同条件下 ,A3钢的电阻值随溶液 pH值增加而增加 ,电容值则相反 .在磷酸锌3.5 %NaCl提取液中 ,因磷酸锌的溶解度太小 ,没有足够的量对金属基底A3钢进行有效的保护 .在 pH值为 6的三聚磷酸铝 3.5 %NaCl提取液中 ,A3钢表现出较明显的缓蚀现象 ,可能是因为三聚磷酸根离子与腐蚀产物Fe2 + 、Fe3+ 络合并在钢表面形成了一层致密的保护膜 ,从而有效地阻止了腐蚀介质的进一步入侵 .防蚀颜料的溶解度大小是决定它的缓蚀性能优劣的重要因素之一     

合成条件对硅胶整体柱中孔结构的影响

硅胶整体柱是目前备受关注的液相色谱固定相。本文考察了合成条件对硅胶整体柱中孔结构的影响,包括反应体系的pH值、聚乙二醇(PEG)含量及分子量。实验表明,反应体系的pH值能有效地调控硅胶整体柱的中孔孔径及孔结构,当pH值为2或5时,整体柱中孔孔径较小;而当pH值为3或9时,孔径较大,孔结构趋于圆筒状。整体柱的中孔平均孔径随着PEG含量和分子量的增加而增加,其孔径分布也逐渐变宽。     

Poly(vinyl chloride) matrix membrane electrode for the selective determination of heroin (diamorphine) in illicit powders

The potentiometric response characteristics of a poly(vinyl chloride) membrane electrode for heroin based on its ion-pair complex with tetraphenylborate were examined. The influence of pH, temperature and time on the performance of the electrode system was investigated. The electrode shows a near-Nernstian response over the heroin concentration range 10(-2)-10(-4) M with good precision. The mean relative standard deviation for the determination of heroin in 40 micrograms ml-1(-1) mg ml-1 aqueous heroin hydrochloride solutions is 1.2%. The electrode exhibits good selectivity for heroin in the presence of a number of adulterants and basic organic compounds commonly present in illicit heroin powders. The method was applied to the direct potentiometric determination of heroin in illicit powders (10-36% heroin) and the results agreed fairly well with those obtained by gas - liquid chromatography.     

2-Nitro-6-monoacetylmorphine: potential marker for monitoring the presence of 6-monoacetylmorphine in urine adulterated with potassium nitrite

6-Monoacetylmorphine (6-MAM), being a unique metabolite of heroin, is routinely tested in urine samples to monitor heroin use. However, detection of 6-MAM-related opiates such as morphine is known to be affected by in vitro urine adulteration using oxidizing adulterants such as potassium nitrite. This study aimed to investigate the fate of 6-MAM after exposure to nitrite and to identify any formed oxidation products that may potentially be used for monitoring heroin abuse despite nitrite adulteration. Potassium nitrite (0.05 M and 0.6 M) was reacted with 6-MAM (5–10,000 ng/mL) in both water and blank urine with pH adjusted to range from 3 to 8. Following reaction at room temperature for varying periods, the reaction mixtures were monitored by both the CEDIA® Heroin Metabolite (6-AM) immunoassay and liquid chromatography-mass spectrometry (LC-MS) methods. Structural elucidation of the isolated oxidation products was based on mass spectrometry and nuclear magnetic resonance spectroscopic evidence. Nitrite, under acidic environment (pH?相似文献   

Use of beta-cyclodextrin in the capillary zone electrophoretic separation of the components of clandestine heroin preparations

The present paper describes the methodological optimization and validation of a capillary zone electrophoresis method for the rapid determination of heroin, secondary products and additives present in clandestine heroin samples, by using 20 mM beta-cyclodextrins in phosphate buffer, pH 3.23. Applied potential was 15 kV and separation temperature was 24 degrees C; detection was by UV absorption at 200 nm wavelength. Heroin samples were first dissolved in CHCl3-MeOH (96:4, v/v) and injected by pressure (0.5 p.s.i., 3 s; 1 p.s.i.=6894.76 Pa) after evaporation of the organic mixture and reconstitution in aqueous buffer. Under the described conditions, phenylethylamine (internal standard), morphine, monoacetylmorphine, heroin, acetylcodeine, papaverine, codeine and narcotine were baseline resolved in less than 10 min. The limit of detection was better than 1 microg/ml for each analyte. The study of the intra-day and day-to-day precision showed, in terms of migration times, RSDs < or = 0.71% and, in terms of peak areas, RSDs < or = 3.2%. Also, the evaluation of linearity and analytical accuracy of the method provided good results for all the analytes investigated, thus allowing its application to real cases of seized controlled drug preparations.     

The Quantitation of Heroin and Selected Basic Impurities Via Reversed Phase HPLC. I. The Analysis of Unadulterated Heroin Samples

Abstract

Methodology was developed employing reversed phase liquid chromatography for the simultaneous determination of heroin, O³-monoacetylmorphine, o⁶-monoacetylmorphine, acetylcodeine, noscapine and papaverine in unadulterated illicit powders. An HS-5 C18 column was used with a gradient system using methanol and a hexylamine phosphate buffer at pH 2.2. This method, suitable for automated analysis, used a multi-mode detection scheme via the use of a photodiode array detector. In order to arrive at the optimum chromatographic conditions in terms of selectivity and stability, a study was performed on the effect of various mobile phase parameters on log k′ for heroin, various impurities, and common adulterants. The mobile phase parameters included amine concentration, organic modifier type, and eluent pH.     

Development of a simple hollow fibre supported liquid membrane extraction method to extract and preconcentrate dinitrophenols in environmental samples at ng L(-1) level by liquid chromatography

An easy and rapid hollow-fibre supported liquid membrane method (HFSLM) has been developed to extract and determinate the total concentration of four dinitrophenols in environmental water at ng L(-1) level. This extraction method provides a high selectivity, short extraction time and very low cost for real samples. It is a three-phase system, aqueous-organic-aqueous, where the organic solvent is held into the fibre pores, being in contact with the two other phases. The organic phase is formed by two different organic solvents, with two different polarities, n-undecane and toluene (1:1). The optimization step was performed using a three-variable Doehler design, involving three factors, stirring speed, fibre length and sample volume. The organic phase composition, as well as the pH of the acceptor and donor phases was also optimized. The extraction equilibrium was reached after 30 min, after which essentially the total amount (90-80%) of the four dinitrophenolic compounds were extracted from the sample. Better repeatability and reproducibility at the expense of lower enrichment factors was obtained compared with other methods, employing incomplete extraction during a fixed time. The matrix effect was tested by performing extractions from leachate water and river water. This method is linear in the range 0.1-100 microgL(-1) in different matrices, with detection limit around 100 ng L(-1), after extraction of 6 mL of sample and using high performance liquid chromatography for final analysis.     

Extraction of molybdenum by a supported liquid membrane method

This is a report on the extraction of molybdenum(VI) ions using a supported liquid membrane, prepared by dissolving in kerosene, the extractant Alamine 336 (a long-chain tertiary amine) employed as mobile carrier. A flat hydrophobic microporous membrane was utilised as solid support. Appropriate conditions for Mo(VI) extraction through the liquid membrane were obtained from the results of liquid-liquid extraction and stripping partition experiments. The influence of feed solution acidity, the carrier extractant concentration in the organic liquid film and the content of strip agent on the metal flux through membrane were investigated. It was established that maximal extraction of metal is achieved at a pH 2.0 if sulphuric acid is used in the feed solution and at a pH value over 11.0 if Na₂CO₃ is used as strip agent. Moreover, the molybdenum extraction through membrane is enhanced when a 0.02 mol l⁻¹ content of the amine carrier in the organic phase is used. The present paper deals with an equilibrium investigation of the extraction of Mo(VI) by Alamine 336 and its permeation conditions through the liquid membrane, and examines a possible mechanism of extraction.     

Applicability of ultra-performance liquid chromatography-tandem mass spectrometry for heroin profiling

The applicability of ultra- performance liquid chromatography tandem-mass spectrometry (UPLC-MS/MS) for heroin profiling is described. The coupling of the high separation power of UPLC with the highly selective and sensitive detection of MS/MS is well suited for heroin profiling. An Acquity UPLC BEH C18 1.7 microm particle column (100 mm x 2.1mm) with binary gradients containing 1% formic acid (pH 2.0) or 10 mM ammonium bicarbonate (pH 10.0)/acetonitrile mixtures was investigated for the profiling. For MS/MS detection, an atmospheric pressure positive electrospray source was employed with multiple reaction monitoring (MRM). MRMs for individual basic impurities were generated for heroin profiling using low and high pH mobile phases, while MRMs for neutral impurities were generated using a high pH mobile phase. Compared to a pH 2.2 mobile phase, the use of a pH 10 mobile phase allowed for significantly greater sample loading, major selectivity differences, and lower MRM sensitivity. UPLC-MS/MS allowed for the highly selective and sensitive detection of many of the targeted solutes in seized heroin exhibits. Basic impurities detected included morphine, codeine, noscapine, papaverine and the previously unreported solutes reticuline, reticuline monoacetate (2 products), reticuline diacetate, narceine, codamine, laudanidine, cryptopine, laudanosine, and norlaudanosine. Neutral impurities found included N,3,6-triacetylnormorphine, N-acetylnorcodeine, N-acetylnornarcotine, 3,6-dimethoxy-4-acetyloxy-5-[2-(N-methylacetamido)]-ethylphenanthrene, and cis-n-acetylanhydronornarceine. The detection of these impurities, at levels as low as 10(-6)% w/w should allow for greatly enhanced heroin profiles.     

三相中空纤维式液相微萃取用于快速富集血浆中的尼古丁

建立了一种以三相中空纤维式液相微萃取(TP-HF-LPME)进行样品前处理,采用高效液相色谱快速、准确测定血浆中尼古丁含量的方法。研究表明该方法集萃取、富集、净化为一步,极大地简化了传统血浆成分测定的前处理过程,是一种快速、有效、绿色的前处理方法。方法的线性范围为0.1～50 mg/L,相关系数(r2)为0.9996,检测限为0.05 mg/L (信噪比为3),相对标准偏差小于5%。     

Liquid-liquid extraction of lysozyme using a dye-modified ionic liquid

An affinity-dye, Cibacron Blue 3GA (CB), derivatized organic salt [BMIM]3[CB] was synthesized for lysozyme extraction. This compound was formed by mixing an ionic liquid (IL) [BMIM][Cl] and the silver salt of CB. Liquid-liquid extractions of lysozyme from the aqueous and [BMIM]3[CB] in [BMIM][PF6] solutions were examined in this study. The transfer of lysozyme from the aqueous phase to the IL phase decreased while the pH of the aqueous phase increased. An extraction higher than 90% was observed at pH 4. Under a high ionic strength, the lysozyme would transform back from the IL phase into the aqueous phase. Lysozyme molecules were almost quantitatively recovered from the IL phase to the aqueous solutions of 1M KCl under pH 9-11. It appeared that the extraction was specific for lysozyme in contrast to cytochrome c, ovalbumin, and bovine serum albumin. The extraction efficiency of the IL phase remained essentially the same after eight cycles of extraction.