变性高效液相色谱及其在法医DNA分析中的应用

变性高效液相色谱(DHPLC)是目前检测基因突变的最佳技术平台之一。本文简要介绍了DHPLC的工作原理及主要技术特点,并对其在法医DNA分析中的应用进行综述。     

Achiral and chiral quantification of methamphetamine and amphetamine in human urine by semi-micro column high-performance liquid chromatography and fluorescence detection

In this paper, miniaturized achiral and chiral high-performance liquid chromatographic procedures for the determination of methamphetamine and amphetamine in human urine are described. After a simple pretreatment of human urine (i.e., 10 microL of urine or diluted urine were acidified and dried-up under N2 at room temperature) and fluorescence derivatization with 4-(4,5-diphenyl-1H-imidazol-2-yl)-benzoyl chloride under mild conditions (pH 9.0, 10 min at room temperature), the derivatives were isocratically separated on a semi-micro ODS column with Tris-HCl buffer (0.1 M, pH 7.0): acetonitrile (45 + 55 v/v) at a flow rate of 0.2 mL/min or their enantiomers were separated on a semi-micro OD-RH column with sodium hexafluorophosphate (0.3 M aq.): acetonitrile (44 + 56 v/v) at a flow rate of 0.1 mL/min as the mobile phase. Wide-ranged calibration curves were obtained with detection limits for the achiral and chiral analyses in the atto and femtomol levels, respectively, per injected volume. Satisfactory within- and between-day reproducibility data were obtained with both the methods with the highest relative standard deviation being 9.6%. The methods were applied to the determination of methamphetamine and amphetamine in human urine samples and the concentrations determined by the two methods were well correlated (r = 0.994).     

Resolution of some enantiomeric amines of forensic interest by high-performance liquid chromatography

The high-performance liquid chromatographic resolution of the enantiomers of amphetamine, methamphetamine, ephedrine, and pseudoephedrine is described. The sugar isothiocyanate, 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate (GITC), is used as a chiral derivatizing agent, with chromatographic separations of the diastereomers formed with each amine made using a standard achiral C18 stationary phase.     

Analysis of forensic soil samples via high-performance liquid chromatography and ion chromatography

Traditional forensic soil comparisons are performed via physical and/or chemical examinations of color, texture, and mineral content, leaving any organic- or water-soluble fractions unexamined. This study uses high-performance liquid chromatography (HPLC) and ion chromatography (IC) to assess the qualitative and quantitative variation in these fractions of soil. Soil samples (n=120) were collected over the course of 3 weeks from urban, suburban, and rural locations in and around Lansing, MI. Additional samples from six of these locations (two urban, two suburban, and two rural) were collected once a week for 10 weeks for temporal analysis. Nine additional samples, equally spaced over a 1 m(2) grid, from these same six locations were collected for spatial analyses. Qualitative and quantitative analysis of the resultant chromatograms separated the 120 samples into 10 groups by HPLC and 23 groups by IC. This study shows that using HPLC and IC to analyze the organic- and water-soluble fractions of soil can successfully discriminate samples. Quantitative analysis of the results eliminates some false inclusions by providing further differentiation of samples. The results of this study indicate that adding HPLC and IC analyses to traditional forensic soil analysis schemes can improve overall sample differentiation. The methods used in this study were also able to detect both qualitative and quantitative variations in soil over a relatively small geographic area. This demonstration of soil heterogeneity underscores the importance of the collection of a representative known sample population when assessing a forensic soil comparison. Significant temporal variation was also demonstrated over the course of 10 weeks of sampling; however, samples were found to be consistent over shorter periods of time. Baseline levels of inorganic anions were determined via IC; these levels may be useful in assessing the significance of anions detected in soil from cases involving low explosives.     

高效液相色谱法快速分离测定血浆中的乌头碱

目的建立血液中乌头碱的高效液相色谱快速分析方法。方法以空白人血浆添加乌头碱标准品对血液样品的前处理方法、仪器测试条件、线性范围、精密度、回收率进行全面考查,建立乌头碱定量分析方法。对血液中所含乌头碱的浓度进行测定。结果该方法在血液中的线性范围是0.1~5.0μg/m l;最低检测浓度为0.1μg/m l;日内、日间精密度分别小于3.7%和4.5%;回收率在(97.0±4.1)%以上。结论所建方法实用、便捷,可对血液中乌头碱的含量进行快速测定。     

Forensic toxicologic analysis of methamphetamine and amphetamine optical isomers by high performance liquid chromatography

Optical isomers (d and l) and racemic compounds (dl) of methamphetamine (MAMP) and amphetamine (AMP), and biologic materials including those substances, could be analyzed by high performance liquid chromatography. Examining the temperature for the analysis, 40 degrees C was the optimal condition in the reproducibility of separated MAMP-isomers. The reproducibility at the temperature did not vary significantly. The measured values of optical isomers were 0.116 +/- 0.012, 1.082 +/- 0.070 and 8.984 +/- 0.136 for the mixing ratios (l/d) of 0.111, 1.000, and 9.000, respectively. The detection limit for both d- and l-isomers was 25 ng. The analytic result of hair specimens from two stimulant abusers by the present method indicates that they contained only d-MAMP and d-AMP, which is believed to have the strongest pharmacologic effect among the optical isomers of MAMP. The coefficient of variation in the analysis of five replicate standards, prepared by adding 1,000 ng each of racemate MAMP and AMP to hair, was less than 4%. The measured value against l/d = 1.000 was 1.040 +/- 0.040 in MAMP and 0.980 +/- 0.030 in AMP. The detection limit for both racemate MAMP and AMP accumulated in hair was 250 ng. The analysis of the optical isomers by our method would contribute to identifying the smuggling routes or the illicit method.     

Rapid screening of selected organic explosives by high performance liquid chromatography using reversed-phase monolithic columns

This study presents the rapid screening of various high grade explosives by high performance liquid chromatography (HPLC) with monolithic stationary phases. Two gradient methods were developed, the first for quantitative analysis of eleven explosives: HMX; RDX; Tetryl; TNT; 2,3-DNT; 2,6-DNT; 3,4-DNT; 2-NT; 3-NT; 4-NT; and PETN in under 14 min. The second method separated seven explosives in under two min and is suitable for rapid screening to determine the presence of specific and/or class of explosive. The rapid screening methods were successfully applied to soils spiked with known amounts of target explosives. This technology showed excellent potential for forensic explosives detection and analysis.     

Forensic application of chiral separation of amphetamine-type stimulants to impurity analysis of seized methamphetamine by capillary electrophoresis

The applicability of capillary electrophoresis (CE) with a UV detector using highly sulfated gamma-cyclodextrin as a chiral selector was examined for analysis of impurities in seized methamphetamine. Samples of methamphetamine-hydrochloride dissolved in water at a high concentration (20 mg/mL) were analyzed. Electrokinetic injection has an advantage over hydrodynamic injection for improving the detection of trace impurities. Small peaks of the precursor impurities, such as (1R,2S)-(-)-ephedrine and (1S,2S)-(+)-pseudoephedrine, were detected and quantified without extraction. The seized drugs could be classified into three groups based on the contents of the two impurities.     

Evaluation of principal components analysis with high-performance liquid chromatography and photodiode array detection for the forensic differentiation of ballpoint pen inks.

Inks from seven black and eight blue ballpoint pens were separated by a high-performance liquid chromatography (HPLC) method utilizing a photodiode array detection (PDA). A classifier flowchart was designed for the chromatographic data based on the presence or absence of certain peaks at different wavelengths to qualitatively discriminate between the inks. The same data were quantitatively classified by principal components analysis (PCA) to estimate the separation between a pair of classes of ink samples. It was found that the black ballpoint pen inks were discriminated satisfactorily utilizing two-dimensional data of the peak areas and retention times at the optimum wavelengths. The blue pens were discriminated by analyzing the chromatographic data at four different wavelengths simultaneously with a cross-validated PCA. The results of this study indicated that HPLC-PDA coupled with chemometrics could make a powerful discriminating tool for the forensic chemist, especially when analyzing extensive and/or complex data.     

人血浆中更昔洛韦的高效液相色谱快速分析

目的建立人血浆中抗病毒药物更昔洛韦的高效液相色谱快速分析方法。方法在一定pH值下用甲醇和二氯甲烷处理血浆,高速离心后外标法直接对上清液进行更昔洛韦定性、定量分析。以正常人血浆为空白样本添加标准更昔洛韦,优化色谱分析条件并确定检材的前处理方法、工作曲线、线性范围、方法的精密度和回收率。以所建方法对12位受试者血浆中更昔洛韦代谢浓度进行12h监测。结果该方法分析血浆中的更昔洛韦,其线性范围为0.05μg/mL～1.60μg/mL;最低检测限为0.01μg/mL(S/N≥3),日内、日间RSD≤5.1%,加样回收率在90.0%～95.4%之间。结论该分析方法操作便捷、实用、准确度高。适用于更昔洛韦的临床血药浓度监测和法医学药(毒)物快速鉴定。     

高效液相色谱法分析红色、绿色摇头丸中的染料

目的根据摇头丸不同的色素成分建立区分摇头丸的方法。方法运用高效液相色谱法分别分析68种红色摇头丸和28种绿色摇头丸。结果 68种红色摇头丸分为7类,28种绿色摇头丸分为4类。结论该方法操作简单、结果准确,可以为侦查提供线索。     

Analysis of penicillins in whole blood by reversed high-performance liquid chromatography

A reversed-HPLC method was established to determinate penicillins in whole blood. Thiamphenicol as internal standard was added to 0.5 ml blood. Proteins in blood were precipitated with acetonitrile, then the separate supernatant was directly injected onto the chromatography column. The range of five penicillins' linearities was 0.9918 to 0.9996, their range of relative recovery was 91.75% to 107.33%, their CV was 3.56% to 9.85%. Effects of different storage temperatures on the stability of analytes and interference of other antibiotics were also studied.     

高效液相色谱法检测人脊髓中的利多卡因

建立高效液相色谱法对人脊髓中利多卡因进行分析的方法 ,以扩大药 (毒 )物检测范围及检测手段 ,适应法医学鉴定及对特殊检材检验的需要。用利多卡因标准品及空白脊髓标准添加实验 ,对色谱条件、样品处理方法、回收率及方法的线性和精密度进行了系统考察。所建方法线性范围是2 0～20 0μg/ml(r=0 9999) ,最低检测限为0 2μg/ml(S/N≥3),加样回收率为82 4 %～92 7% ,该法选择性好、不受干扰。所建方法灵敏、准确、简捷 ,可用于法医学鉴定。     

人脑脊液中利多卡因的高效液相色谱分析

目的 建立人脑脊液中利多卡因的高效液相色谱(HPLC)分析方法。方法 以空白人脑脊液添加标准利多卡因进行HPLC分析,并系统考察实验中的色谱条件、样品处理方法、线性关系、精密度及回收率。结果 所建方法的线性范围是1.0～20.0μg·ml-1(r=0.9993),最低检测浓度为1.0μg·ml-1(S/N≥3),日内、日间检测的相对标准偏差≤3.0％,回收率为98.3％～102.7％。结论 所建方法定量检测人脑脊液中的利多卡,灵敏、准确、快速。     

The analysis of forensic samples using laser micro-pyrolysis gas chromatography mass spectrometry

Laser micropyrolysis gas chromatography-mass spectrometry is used for the analysis of paint, photocopier toner, and synthetic fiber materials to test the forensic potential of this emerging technology. It uses a laser microprobe to selectively target very small parts of the materials for GC-MS analysis. Whereas the paint and the toner samples were amenable to direct laser pyrolysis, the synthetic fibers proved transparent to the 1064 nm laser radiation. The difficulty with the fibers demonstrates that a specific laser wavelength may not be appropriate for all types of materials. Nevertheless, the fibers were able to be indirectly pyrolyzed by impregnation in a strongly absorbing graphite matrix. A vast array of hydrocarbon pyrolysates was detected from the different materials studied. Unique product distributions were detected from each sample and in sufficient detail to facilitate individual molecular characterization (i.e., molecular fingerprinting). The integrity of the laser data were confirmed by comparison to data obtained from the same samples by the more conventional pyroprobe pyrolysis GC-MS method. The high spatial resolution and selectivity of the laser method may be advantageous for specific forensic applications, however, further work may be required to improve the reproducibility of the data.     

Chemico-toxicological analysis of haloperidol in blood with high-performance liquid chromatography in combined poisoning

Haloperidol is widely used in psychiatric practice both in monotherapy and in combination with neuroleptics, phenothiazine derivatives (chlorpromasin, levomepromasin) and antidepressants (amitriptilin, imipramin). We have developed techniques of haloperidol isolation from blood in combined poisonings with phenothiazine derivatives (chlorpromazine, levomepromasine) and antidepressants (amitriptilin, imipramin), their identification and quantitation with high-performance liquid chromatography. The highest output of the substances studied was achieved in alkaline hydrolysis. The techniques are expressive, sensitive and well reproducible. This makes them convenient for practice of forensic-chemical and chemico-toxicological laboratories.     

The methodological aspects and prospects of using dynamically modified sorbents for the analysis of biological specimens by means of high-performance liquid chromatography]

Published reports and authors' experience gained in high-performance liquid chromatographic analysis of dynamically modified adsorbents are reviewed. The advantages of this variant of liquid chromatography are shown: the method is economic and more effective for analysis of mixtures of a complex composition, including biological objects. Examples of mycotoxin, morphine, and other toxicologically significant agents are offered. The method is recommended for wide use in forensic medical expert evaluations.     

高效液相色谱法分离测定药酒中乌头碱的含量

目的建立药酒中乌头碱的高效液相色谱快速分析方法。方法以白酒添加乌头碱对照品对药酒样品的前处理方法、仪器测试条件、线性范围、精密度、回收率进行全面考察,建立定量分析方法。对药酒中所含乌头碱的浓度进行测定。结果该方法乌头碱在药酒中的线性范围是0.45～9.0μg·mL-1;日内、日间精密度分别小于3.1%和4.7%;回收率在(97.3±2.8)%以上。结论所建方法实用、便捷,可对药酒中乌头碱的含量进行快速检测。     

液相电喷雾离子质谱技术在法医DNA中的应用

生物质谱技术是近年来发展较为迅速的生物分析技术之一,在对大分子生物质量测定中,其以快速、准确、灵敏等优点受到研究者的青睐。其中,液相电喷雾离子电离质谱(LC-ESI-MS)在法医DNA分析中对STR以及SNP遗传标记的检测具有独特的应用价值和广阔的应用前景。本文对ESI-MS的现状和在法医DNA分析中的应用等方面进行了综述,分析了LC-ESI-MS技术在法医学DNA分析中的优缺点,以促进其在国内法医DNA分析中的应用与发展。     

Determination of benzodiazepines in human hair by on-line high-performance liquid chromatography using a restricted access extraction column.

A method is described for the identification of five frequently prescribed benzodiazepines (BZD) (clonazepam, diazepam, flunitrazepam, midazolam and oxazepam) in human hair samples by reversed phase HPLC, following on-line simple enrichment and clean-up on a restricted access extraction column. 50mg of powdered hair were incubated (2h at 45 degrees C) after sonication (1h) in 1 ml of the following solution (methanol:ammonia, 97.5/2.5, v/v). The aliquot was centrifuged and the methanolic phase transferred to a conical tube and evaporated under a gentle stream of nitrogen. The residue was reconstituted by adding 100 microl of a mixture of phosphate buffer (20mM, pH=2.2) and acetonitrile (94/6, v/v). A total of 80 microl were injected into the system with the column switching technique. The pre-column or clean-up column was washed with phosphate buffer pH=7.2. The drugs retained on the pre-column were then eluted in the back-flush mode and separated on a C(8) semi micro column, Lichrospher select B, 125 mm x 3 mm. The BZD were determined by a photodiode-array detector at 254 nm, using reference data (retention time and UV spectra) stored in a personal library. The method showed excellent linearity between 0.5 and 20 ng/mg of hair for clonazepam, flunitrazepam and midazolam and between 0.5 and 100 ng/mg of hair for diazepam and oxazepam. Finally, the present method has been applied to a number of forensic cases in our laboratory.