利用毛细管电泳和判别分析判断海洛因地理来源

对在中国境内缴获的海洛因样本进行地理来源判断.采用动态涂层毛细管电泳技术(CE)对海洛因样本进行生物碱检测,并利用判别分析法对检测数据进行统计学分析,达到了对中国境内缴获的海洛因样本进行地理来源推断的目的.     

气相色谱/氢火焰检测器快速检测海洛因毒品及其来源推测

建立一种海洛因样本的快速检测和来源推测的方法。采用气相色谱/氢火焰检测器(GC/FID)和主成分分析(PCA)的方法对675份云南、新疆两地海洛因样本进行了检测,实现了云南、新疆两地缴获海洛因毒品的特征性划分,阳性率达到83.5%以上。采用GC/FID技术和主成分分析的方法可以实现海洛因样本地理来源区分。     

使用模拟技术建立海洛因样本的HPLC快速分析方法

采用TRYLAB模拟技术和高效液相色谱技术(HPLC)对实际海洛因样本进行优化,建立一种海洛因样本的HPLC快速分析方法,实现了海洛因样本中7类生物碱的分离,其中海洛因和单乙酰吗啡之间的分离度达到2. 16,海洛因定量曲线的线性相关系数为0. 99993,定量限为0. 001～1. 000 mg/mL;使用该数学模拟技术可以迅速有效地帮助各级实验室建立优化的海洛因HPLC分析方法.     

近红外光谱法非破坏性同时测定海洛因、O6单乙酰吗啡、乙酰可待因

提出了近红外漫反射光谱快速无损测定缴获白粉中海洛因、O6单乙酰吗啡、乙酰可待因含量新方法。采用GC-MS分析了缴获88份白粉中这3组分的质量百分含量范围分别为12.15%~79.54%,0.4%~18.56%,0.23%~9.11%。以交叉验证误差均方根(RMSECV)为指标,确定各组分用于建模的最优近红外波段和光谱预处理方法,采用偏最小二乘算法建立近红外光谱与这三组分GC-MS分析值之间的校正模型,并以此预测了35个白粉样本。δ代表预测样本NIR值/GC-MS值,海洛因、O6单乙酰吗啡、乙酰可待因δ值的均值为100.63%,100.35%和98.71%,RSD分别为3.96%,7.02%,8.54%。该方法快速无损,结果可靠。     

偏最小二乘变量筛选法在毒品来源分析中的应用

提出了一种新的偏最小二乘变量筛选方法,该方法利用PLS回归建模过程中的一些信息,删除一部分冗余的或对建模影响不大的变量来简化、优化预报模型。用此方法结合变量扩维方法处理云南昆明、思茅、西双版纳3个来源地缴获的244个海洛因样本的ICP-MS数据时,与传统的算法比较,模型的判别准确率得到大大提高,达到95%以上。且所得到的模型含变量少,很容易分析或解释各变量对模型的影响。因此该方法可用于对毒品来源有效的识别或鉴定。     

UPLC-MS/MS和主成分分析法判别海洛因原产地

建立了超高效液相色谱-串联四极杆质谱仪(UPLC-MS-MS)在电喷雾离子源正离子(ESI+)和多反应监测(MRM)模式下定量测定海洛因中9种生物碱的方法,并采用主成分分析法建立数学模型,实现了快速区分"东南亚"和"西南亚"地区海洛因样品的目的。样品使用甲醇超声提取,ACQUITY UPLC BEH C18(100 mm×2.1 mm i.d.,1.7μm)色谱柱,流动相为pH 9.66的10 mmol/L的碳酸氢铵和乙腈,在梯度条件下分析。结果表明,在5～500μg/kg添加水平下回收率范围为88%～118%,相对标准偏差为1.7%～10%。9种生物碱的检出限(LOD,以信噪比(S/N)>3计)和定量限(LOQ,以S/N>10计)分别为0.03～1.67 mg/kg和0.10～5.51 mg/kg。本方法在11 min内即可对缴获海洛因样品中的9种生物碱进行定量分析,可用于海洛因原产地的快速判别。     

PyGC法对海洛因样品定量分析方法的改进

本文采用PyGC法对不同来源的海洛因进行了分类研究,由于实验精确度的要求,对裂解气相色谱的进样方法进行了改进,提高了实验数据的重复性。     

基于光谱融合-特征提取的海洛因及其添加剂无损分类研究

在近年来的多数治安案件中,有不少是由形形色色的毒品所引起的。为了提高检验的效率,降低检验成本,实现对海洛因样本主成分及添加剂的无损分类,提出了一种基于光谱融合,主成分分析和判别分析的鉴别方法。采集并获取了不同质量分数和添加剂共计45个海洛因样本的红外光谱,选择一阶求导、多元散射校正、Savitzky-Golay平滑和峰面积归一化开展预处理工作,并利用主成分分析进行特征变量提取和采用Fisher判别分析构建判别分类模型。实验对单独的原始光谱数据,一阶导数光谱数据和融合后的光谱数据进行比较。无论是对海洛因主成分的质量分数进行分类,还是对海洛因的添加剂分类,单一的分类模型都仅能实现66.7%～88.9%的准确区分。结果表明,基于融合的光谱数据构建的判别模型分类准确率更高,对主成分质量分数和海洛因添加剂的分类,均能达到100.0%。利用红外光谱数据融合技术结合主成分分析和判别分析达到了降低检验成本且无损的目的,能够最大程度的限制毒品的流动,对今后的毒品检测和维护社会治安稳定具有一定的贡献。     

化学计量学在海洛因来源判别中的应用

介绍化学计量学在非法海洛因来源判别中的意义和需求,并结合国际上关于非法海洛因来源判别的应用现状和技术特点讲述了化学计量方法的应用种类和特点。虽然各国所采用的化学计量学方法各异,但基本上可以划分为表观判别法和数理统计法两大类。     

质量平衡法测定盐酸海洛因纯度

研究了盐酸海洛因纯度的定值技术.对经筛选的盐酸海洛因原料进行液相色谱-质谱、红外光谱、核磁及离子色谱定性分析,采用质量平衡法对盐酸海洛因原料进行纯度测定.在基于色谱的质量平衡法的基础上优化了检测条件,确定了主成分的含量,用卡尔费休法测定样品水分含量,最终得到盐酸海洛因纯度定值为95.1％.该分析结果的标准不确定度为0....     

Bulk and compound-specific isotopic characterisation of illicit heroin and cling film

Comparative analysis involves various but complementary methods and can be used for forensic intelligence purposes to group seizures of heroin into batches. Much forensic analysis now combines expertise in the traditional area of drugs investigation with a detailed understanding of supply, packaging, distribution, and drugs intelligence. It was the intention of this research to determine whether illicit heroin seizures and packaging material can be grouped according to isotopic compositions, and to explore factors that affect the isotopic compositions. In order to achieve these aims, 14 samples of seized heroin, thirteen provided by Avon and Somerset Constabulary (UK), were analysed by elemental analysis/isotope ratio mass spectrometry (EA/IRMS) and gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) for carbon and hydrogen isotopes. These tests elucidated that a combination of the delta13C, delta15N, delta18O and delta2H results from EA/IRMS is able to distinguish between most samples of bulk heroin. We speculate that the delta13C values of the alkaloids, obtained by GC/C/IRMS, give indications of different geographical or temporal origins of some of the heroin samples. GC/C/IRMS of the cutting agent, caffeine, provides a means to link dilution events. Fifteen retail cling film samples and seven cling film samples from heroin seizures were analysed by EA/IRMS. A multivariate comparison of the carbon, hydrogen and oxygen isotope ratios was able to distinguish between most of the samples. This technique enabled the cling films from the heroin to be grouped according to seizure. Three solvents were tested on two samples of cling film of known composition. Methanol and chloroform were both found to extract material from PVC and from non-PVC cling films. Water-treated PVC was indistinguishable from the untreated PVC and thus water was found to be the most suitable solvent when washing cling film prior to IRMS analysis.     

Rapid and cost‐effective method for the simultaneous quantification of seven alkaloids in Corydalis decumbens by microwave‐assisted extraction and capillary electrophoresis

A rapid and cost‐effective method based on microwave‐assisted extraction followed by capillary electrophoresis was developed for simultaneous quantification of seven alkaloids in Corydalis decumbens for the first time. The main parameters affecting microwave‐assisted extraction and capillary electrophoresis separation were investigated and optimized. The optimal microwave‐assisted extraction was performed at 40°C for 5 min using methanol/water (90:10, v/v) as the extracting solvent. Electrophoretic separation was achieved within 15 min using an uncoated fused‐silica capillary (50 μm internal diameter and 27.7 cm effective length) and a 500 mM Tris buffer containing 45% v/v methanol (titrated to pH^* 2.86 with H₃PO₄). The developed method was successfully applied to the quantification of seven alkaloids in Corydalis decumbens obtained from different regions of China. The combination of microwave‐assisted extraction with capillary electrophoresis was an effective method for the rapid analysis of the alkaloids in Corydalis decumbens .     

Capillary electrophoresis separation and permanganate chemiluminescence on-line detection of some alkaloids with beta-cyclodextrin as an additive.

Capillary electrophoresis has been used in combination with on-line permanganate chemiluminescence detection for the simultaneous determination of morphine, 6-monoacetylmorphine and heroin. It was found that beta-cyclodextrins could improve the separation efficiency and enhance the chemiluminescence signal. Improved sensitivity over capillary electrophoresis with UV detection was obtained. The procedure has detection limits of 23, 66 and 115 fmol for morphine, 6-monoacetylmorphine and heroin, respectively.     

CE‐MS analysis of heroin and its basic impurities using a charged polymer‐protected gold nanoparticle‐coated capillary

The first application of charged polymer‐protected gold nanoparticles (Au NPs) as semi‐permanent capillary coating in CE‐MS was presented. Poly(diallyldimethylammonium chloride) (PDDA) was the only reducing and stabilizing agent for Au NPs preparation. Stable and repeatable coating with good tolerance to 0.1 M HCl, methanol, and ACN was obtained via a simple rinsing procedure. Au NPs enhanced the coating stability toward flushing by methanol, improved the run‐to‐run and capillary‐to‐capillary repeatabilities, and improved the separation efficiency of heroin and its basic impurities for tracing geographical origins of illicit samples. Baseline resolution of eight heroin‐related alkaloids was achieved on the PDDA‐protected Au NPs‐coated capillary under the optimum conditions: 120 mM ammonium acetate (pH 5.2) with addition of 13% methanol, separation temperature 20°C, applied voltage ?20 kV, and capillary effective length 60.0 cm. CE‐MS analysis with run‐to‐run RSDs (n=5) of migration time in the range of 0.43–0.62% and RSDs (n=5) of peak area in the range of 1.49–4.68% was obtained. The established CE‐MS method would offer sensitive detection and confident identification of heroin and related compounds and provide an alternative to LC‐MS and GC‐MS for illicit drug control.     

Fragmentation pathways of heroin-related alkaloids revealed by ion trap and quadrupole time-of-flight tandem mass spectrometry

The electrospray ionization (ESI) ion trap and quadrupole time-of-flight (QqToF) mass spectra of heroin and seven related alkaloids, i.e., morphine, codeine, O-6-monoacetylmorphine (6-MAM), thebaine, acetylcodeine, papaverine and narcotine, have been extensively investigated in this work. The ESI mass spectrometric fragmentation pathways of protonated 6-MAM, heroin, acetylcodeine, and thebaine were comprehensively elucidated for the first time with the aid of high-resolution mass spectrometry. It was found that cleavage of the piperidine ring was the featured fragmentation route of six of the compounds, although not of papaverine and narcotine. In addition, a simple high-performance liquid chromatography (HPLC)-based separation method gave baseline resolution of all eight components. This study could play an important role in the screening for these alkaloids in different matrices by HPLC coupled to tandem mass spectrometry (MS/MS).     

Possibilities and limitations of different modes of capillary electrophoresis for the quantitative determination of catechols and caffeine in black and green tea

Methods of capillary electrophoresis (capillary zone electrophoresis, micellar electrokinetic chromatography, and microemulsion electrokinetic chromatography) were compared in determining polyphenolic antioxidants and alkaloids in black and green tea. It was shown that reverse-flow micellar electrokinetic chromatography (RF-MEKC, pH < 2.5) using reversed pola rity is most preferable for the rapid simultaneous determination of catechols and caffeine. The detection limit was 1 mg/L.     

Principal opium alkaloids as possible biochemical markers for the source identification of Indian opium

A total of 124 opium samples originating from different licit opium growing divisions of India were analyzed for their principal alkaloid (thebaine, codeine, morphine, papaverine, and narcotine) content by capillary zone electrophoresis (CZE) without derivatization or purification. Absence of papaverine in Bareilly, Tilhar, and most of the samples originating from Kota is a significant observation in relation to the source of Indian opium. Multiple discriminant analysis was applied to the quantitative principal alkaloid data to determine an optimal classifier in order to evaluate the source of Indian opium. The predictive value based on the discriminant analysis was found to be 85% in relation to the source of opium and the study also revealed that all the principal alkaloids have to be analyzed for source identification of Indian opium. Chemometrics performed with principal alkaloids analytical data was used successfully in discriminating the licit opium growing divisions of India into three major groups, viz., group I, II, and III. The methodology developed may find wide forensic application in identifying the source of licit or illicit opium originating from India, and to differentiate it from opium originating from other opium producing countries.     

Determination of Dissociation Constants of Strychnos Alkaloids from Strychnos nux-vomica L. by Capillary Electrophoresis

An accurate capillary electrophoresis method was developed for the determination of dissociation constants of five Strychnos alkaloids from Strychnos nux-vomica L. The method relies on measuring the effective mobility of the solute as a function of the buffer pH. The mathematical relationship was strictly derived from the fundamental electrophoresis theory and the dissociation equilibrium of a weak base without any simplifications. Careful optimization of the running buffer permitted base-line resolution of the five structurally similar alkaloids.