Analysis of methylbenactyzium bromide in human urine by thin-layer chromatography and pyrolysis gas chromatography.

A rapid and simple method of utilizing thin-layer chromatography (TLC) and pyrolysis gas chromatography (PyGC) for the identification and determination of methylbenactyzium bromide in human urine was studied in this report. Methylbenactyzium bromide was extracted from urine with ODS-cartridge (Sep-Pak C18), then spotted onto a silica gel 60 F254 TLC plate. After development, the separated spot of methylbenactyzium bromide was scraped and wrapped with a ferromagnetic foil without extraction by any organic solvents. The sample was applied into PyGC analysis. The optimum temperature for pyrolysis was 590 degrees C. The main degradation product of methylbenactyzium bromide was identified as diphenylmethane in this procedure by gas chromatography/mass spectrometry (GC/MS). A calibration graph prepared by absolute calibration method showed a good linearity over the concentration range of 1-75 micrograms/spot for methylbenactyzium bromide. The coefficient of variation obtained for eleven replicate analyses of the 3 micrograms/spot of standard methylbenactyzium bromide was 3.8%. The detection limit of this compound by this procedure was 0.1 micrograms/spot.     

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.     

GC/MS、GC/NPD法检测毛发中的氯胺酮

目的采用液-液萃取、衍生化和GC/MS、GC/NPD方法,进行毛发中氯胺酮定性定量分析。方法选择4-苯基丁胺为内标,毛发样本用NaOH、HCl及芳基硫酸酯酶/β-葡萄糖醛酸酶等3种方式进行水解,再进行衍生化后,采用GC/MS和GC/NPD方法定性定量分析。对不同水解和衍生化条件以及提取溶剂进行比较优化,并考察方法精密度、稳定性和检出限。结果方法的提取回收率大于95%,精密度和样品稳定性良好,日内和日间标准偏差小于6%;采用GC/NPD和GC/MS直接分析毛发中的氯胺酮,检出限为0.2ng/mg和2.0ng/mg,线性范围为10.0～250.0ng/mg,相关系数均大于0.99;采用酰化衍生化后分析,GC/NPD和GC/MS检出限分别提高至0.1ng/mg和0.2ng/mg。结论该方法回收率高、检测限低,可以用于毛发中氯胺酮的定性定量分析检验。     

Analysis of amphetamines by supercritical fluid chromatography,high-performance liquid chromatography,gas chromatography and capillary zone electrophoresis; a preliminary comparison

A supercritical fluid chromatographic method with UV detection (SFC–UV) for the quantitative separation of phenylisothiocyanate (PITC)-derivatised amphetamines is described and compared to high-performance liquid chromatography–diode array detection (HPLC–DAD), gas chromatography–flame ionisation detection (GC–FID) and capillary zone electrophoresis–diode array detection (CZE–DAD) analyses of amphetamine and related compounds. Difficulties in the analysis of common amphetamines by SFC are discussed. Of the methods described in this paper, the SFC method offered the greatest sensitivity at 0.01–0.02 μg of drug on column. Suggestions are made for the use of combinations of these techniques for the identification of amphetamines when gas chromatography–mass spectrometry is not available.     

Packed column chromatography, high-resolution gas-chromatography and high pressure liquid chromatography in comparison for the analysis of cannabis constituents

The identification and the quantitative estimation of cannabis constituents is important for forensic purposes. High resolution gas-chromatography gives better results than gas-liquid chromatography with packed columns, as it shows a better resolution and higher number of constituents. Different quantitative values were found with the two chromatographic procedures. High-pressure liquid chromatography revealed the presence of cannabinoid acids in fresh cut influorescences of cannabis plants. The ratio acid/neutral cannabinoid may be useful in supplying information about the age of the cannabis preparations.     

Detection of acetic acid in cadavers by gas chromatography

A simple technique of sample preparation for gas chromatographic test for acetic acid in cadaveric material has been developed. The background concentration of natural content of acetates in the stomach, liver and kidneys are determined. The error of the method is no more than 10% with standard deviation +/- 0.04-0.13.     

人血浆中尼莫地平气相色谱分析方法

建立人血液中尼莫地平的气相色谱分析方法 ,扩大药物检测范围及检测手段 ,以适应法医学鉴定的需要。以NaNO2 为氧化剂 ,将尼莫地平完全氧化成其吡啶衍生物 (PA)后用GC ECD进行分析。以标准尼莫地平对方法的线性范围、精密度进行了测试 ;以人血浆标准添加尼莫地平对样品处理方法、回收率进行考察。所建方法的线性范围是 1 2 1～ 2 4 2ng·ml 1(γ =0 9993) ;最低检出限为 1 0mg·ml 1(S/N =3) ;日内与日间的变异系数分别为 (5 77± 2 31) %与 (5 5 3± 0 70 ) % (n =4) ;平均回收率为 91 0 %～ 99 9%。该方法可用于尼莫地平血药浓度监测及法医学鉴定。     

HS-GC／FID分析血中的乙醚

目的建立顶空GC/FID分析血中乙醚的方法。方法用顶空GC/FID分析血中乙醚,并对萃取条件和色谱条件进行优化。结果方法的检出限为0.3ug/ml,回收率为81%,相对标准偏差为4.4%。结论该法简便、快速、灵敏,适合毒物分析检验的要求。     

Supercritical fluid chromatography in forensic science: a critical appraisal

The application of supercritical fluid chromatography (SFC) in forensic science is reviewed. The applications centre on the analysis of explosives and of drugs of abuse. The systems employed are discussed in the context of comparison with gas chromatography and high-performance liquid chromatography methods which are traditionally used for such analyses. The advantages and disadvantages of SFC over these methods are discussed. Recommendations are made for the developments which are required in SFC technology if it is to find greater application in forensic science.     

二维气相色谱检测爆炸残留物中TNT

目的建立二维气相色谱结合ECD检测爆炸残留物中TNT的方法。方法利用Dean-Switch系统进行二维无死体积切换，通过切换时间的准确选择，使粉尘样品提取液无需净化进样，即可达到分离彻底、高灵敏度。结果在案件检测应用中，效果良好。