High performance liquid chromatographic determination of alcohols with reference to body distribution of methanol

A method has been developed on reverse phase high performance liquid chromatography for simultaneous determination of methyl, ethyl and isopropyl alcohols under refractive index detection using pure water as the mobile phase. A good separation has been achieved between these alcohols. Detector response was linear with a detection limit of 5 mg/100 ml. Recovery studies were performed by adding known amounts of methyl and ethyl alcohols to blood, lung and liver within the range 80–90%. The reproducibility of the results was always >90%. The quantitative distribution of methyl alcohol in postmortem body tissues and fluids has been reported in three cases of poisoning.     

Unified gas chromatography method for the detection of volatile toxicants in biological samples

A method was designed to identify and quantify the volatile toxicants in cadaveric samples; it is based on analyzing the equilibrium of the gas-vapor phase. A system comprising 3 gas chromatography columns with different polarities and without preliminary isolation of an analyzed substance is used in toxicants' identification. 0.2% n-propanol solution was used in quantification of fresh biological samples, while methanol solution was used in cases of purulence-affected materials. The method sensitivity provides for detecting some of the toxicants, like acetaldehydes, acetone as well as ethyl and higher alcohols at the level of their natural content. The method has been tested for as long as 15 years at expertise objects.     

Rapid Separation of Organophosphate Pesticides using Micellar Electrokinetic Chromatography and Short‐end Injection,

Organophosphate (OP) pesticides are highly toxic substances and are frequently represented as poisons. In order to qualify and quantify the selected OP pesticides (methyl paraoxon, ethyl paraoxon, methyl parathion, fenitrothion, and ethyl parathion), micellar electrokinetic chromatography and short‐end injection were investigated. This is the first time that this combination has been used to separate OP pesticides. A capillary with 8.5 cm effective length was used, and the analytes were separated within 2.1 min. Separation conditions including buffer (type, pH, and concentration), sodium dodecyl sulfate concentration, and separation voltage were optimized. The limit of detection (LOD) was estimated in the range of 10–20 μM. The OP pesticides spiked in artificial saliva and drinking water gave superior peak profiles, and good average recoveries 95.6% and 62.3%, respectively. Overall, a rapid method with excellent resolution and efficiency was developed and successfully applied in the analysis of potential sample matrixes.     

肝中对硫磷的固相萃取—电子捕获检测气相色谱分析法

目的建立肝中对硫磷的快速、灵敏、可靠的GC／ECD分析方法。方法肝匀浆加内标甲基对硫磷,用乙腈浸提,浸提液加6％高氯酸稀释,稀释的上清液用GDX403树脂进行固相提取,提取物用HP-5色谱柱和电子捕获检测器进行气相色谱分析。结果提取率92.3％,检测限7.8ng／g,线性范围0.04～4.0μg／g,回收率99.6％±6.2％(Mean±CV,n=5)。结论方法简便、灵敏适合于实际案件检验。     

Desorption electrospray tandem MS (DESI-MSMS) analysis of methyl centralite and ethyl centralite as gunshot residues on skin and other surfaces

Abstract:  A direct and sensitive method for the detection of methyl centralite (MC) and ethyl centralite (EC) as gunshot residues (GSRs) has been developed. This method uses desorption electrospray ionization (DESI)-tandem mass spectrometry and directly desorbs and detects analytes from surfaces without any sampling process. Typical transitions for MC and EC, m/z 241 to m/z 134 and m/z 269 to m/z 148, respectively, were used to improve the assay sensitivity. It has been shown that MC and EC can be detected on various surfaces, with detection limits of 5–70 pg/cm². Interferences, detection time after shooting and the number of times hands were washed after shooting were also evaluated. None of the materials interfered with the results and the detection window for organic GSRs was up to 12 h and hands could be washed at least six times. Further samples were analyzed to confirm the reliability of this method, and showed that it could discriminate shooters from nonshooters. This method should be of significance in forensic science, especially in analyzing GSRs, because of its simplicity, high throughput, and the direct detection of MC and EC on suspects' hands, clothes, and hair.     

Improved method for the detection of TATP after explosion

TATP in post explosion exhibits was reported earlier to be best recovered from vapor phase. A typical procedure includes its adsorption on Amberlite XAD-7, elution with acetonitrile and analysis by GC/MS. In this work, improved recovery of TATP from the vapor phase was achieved by SPME using PDMS/DVB fiber and immediate sampling to GC/MS. The recovery of TATP by SPME was compared with headspace and with adsorption on Amberlite XAD-7 by spiking onto filter paper put in a 100 mL beaker. The limit of detection of TATP was 6.4 ng in these conditions, few orders magnitude more than in the other tested methods. Recovery of TATP in the presence of various solvents was also studied. Acetone, water, and mixtures of water:alcohols (1:1) were found to reduce the recovery of TATP. Using SPME, TATP has been identified in dozens of post-explosion cases.     

Tropane ethyl esters in illicit cocaine: isolation, detection, and determination of new manufacturing by-products from the clandestine purification of crude cocaine base with ethanol

Seven ethyl homologues of known tropane esters have recently been detected as impurities in the gas chromatographic signature profiles of authentic Peruvian illicit cocaine base and hydrochloride exhibits. Peruvian cocaine base processors are now known to use ethanol for the purification of crude cocaine base. This process is referred to as the "base lavada" or "washed base" process and is a recent substitute method for the potassium permanganate oxidation purification methodology. Seven ethyl ester homologues were formed in illicit cocaine from the transesterification of known tropane methyl esters or possibly ethyl esterification of their respective tropane C-2 carboxylic acids in the presence of ethanol. Exhibits containing these compounds were subjected to gas chromatographic-mass spectrometric analyses to determine their identity and were subsequently synthesized to verify their structures. Quantitative determinations were obtained from ion-pair chromatography isolation followed by gas chromatography with flame ionization detection. Specifically, hexanoylecgonine ethyl ester, cocaethylene, cis-cinnamoylecgonine ethyl ester, trans-cinnamoylecgonine ethyl ester, 3',4',5'-trimethoxybenzoylecgonine ethyl ester, cis-3',4',5'-trimethoxycinnamoylecgonine ethyl ester, and trans-3',4',5'-trimethoxycinnamoylecgonine ethyl ester were detected and characterized. When present, these compounds were detected at levels ranging from 8.6 x 10(-4) to 9.3 x 10(-1)% relative to cocaine.     

The forensic analysis of thermal transfer printing

Thermal transfer printing refers to printing processes that utilize heat to produce an image by either physical or chemical means or by a combination of both. As the technology has improved and the supplies have become less expensive, the use of thermal printing in the personal and business markets has increased significantly. Specifically, dye diffusion thermal transfer and thermal mass transfer have become predominant in the production of counterfeit credit cards, drivers' licenses, and other types of documents produced on plastic media. Chemical analysis by means of thin layer chromatography (TLC) has proven to be useful in characterizing various types of inks (e.g., writing and inkjet inks). In this study, the authors examined 81 different samples that included a total of 54 printer samples (43 photographic prints on paper and eleven plastic card samples) and 27 printer ribbons. A new TLC method was developed and tested utilizing a solvent system (80% n-hexane, 3% methyl ethyl ketone, and 17% ethyl acetate) that is capable of producing excellent resolution.     

A routine screening method for the major metabolite of methyl phenidate in the urine of greyhounds

A qualitative urine screening procedure for the determination of the major urinary metabolite of methyl phenidate, α-phenyl-2-piperidine acetic acid (ritalinic acid), has been devised.The method involves a salting-out extraction, conversion of the metabolite to the parent drug using methanol-hydrogen chloride, and simultaneous two-column gaschromatographic detection. Final confirmation of the presence of the drug is by two-system thin-layer chromatography. The method is suitable for the detection of illicitly administered methyl phenidate in greyhounds.     

Analysis of fatty acid ethyl esters in hair as possible markers of chronically elevated alcohol consumption by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS)

Fatty acid ethyl esters (FAEE) are products of the nonoxidative ethanol metabolism, which are known to be detectable in blood only about 24h after the last alcohol intake. After deposition in hair they should be suitable long-term markers of chronically elevated alcohol consumption. Therefore, a method for the analysis of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate from hair was developed based on the extraction of the hair sample by a dimethylsulphoxide (DMSO)/n-hexane mixture, separation and evaporation of the n-hexane phase and application of headspace solid-phase microextraction (HS-SPME) in combination with gas chromatography-mass spectrometry (GC-MS) to the extract. For use as internal standards, the corresponding D(5)-ethyl esters were prepared. The HS-SPME/GC-MS measurements were automatically performed using a multi-purpose sampler. The detection limits of the FAEE were between 0.01 and 0.04ng/mg and the reproducibility was between 3.5 and 16%. By application of the method to hair samples of 21 fatalities with known heavy alcohol abuse 0.045-2.4ng/mg ethyl myristate, 0.35-13.5ng/mg ethyl palmitate, 0.25-7.7ng/mg ethyl oleate and 0.05-3.85ng/mg ethyl stearate were measured. For social drinkers (30-60g ethanol per week), the concentrations were about one order of magnitude smaller. For 10 teetotalers negative results or traces of ethyl palmitate were found. It was shown by supplementary investigations in single cases that FAEE are also present in sebum, that there is no strong difference in their concentrations between pubic, chest and scalp hair, and that they are detectable in hair segments after a 2 months period of abstinence. From the results follows that the measurement of FAEE concentrations in hair is a useful way for a retrospective detection of alcohol abuse.     

Detection of cocaine and its polar transformation products and metabolites in human urine

This paper describes a method for the analysis of thermal degradation compounds generated from cocaine during the smoking process, together with chemical and enzymatic biotransformation products which, by virtue of their polarity, are not recovered by existing analytical procedures. The method employs cation exchange solid phase extraction coupled with gas chromatography/mass spectrometry. Compounds identified in urine from subjects of cocaine-related death included cocaine, benzoylecgonine, ecgonine methyl ester and ecgonine, which were measured quantitatively, and ecgonidine, ecgonidine methyl ester, ecgonine ethyl ester, ethyl benzoylecgonine, norcocaine, benzoylnorecgonine, cinnamoylcocaine, and cinnamoylecgonine. The concentrations of ecgonine (0–104 μg/ml) and ecgonine methyl ester (0–177 μg/ml) were substantial and averaged about one tenth the concentrations of benzoylecgonine (0–1074 μg/ml) and cocaine (0–1221 μg/ml). These and several of the other compounds identified will be valuable markers for cocaine use, in degraded samples and for indicating the route of administration.     

全血中西地那非的HPLC分析

目的建立血中西地那非的HPLC-DAD检测方法。方法用硅胶小柱分离提取血中的西地那非,HPLC-DAD分析。分析柱：Nova-pak C18（150×3.9mm）,5.0μm;保护柱：Phenom enex C18（ODS,4.0×3.0mm,Octade-cyl）;流动相A：0.06%三氟乙酸＋0.06%三乙胺＋0.25%乙腈,B：乙腈,梯度程序分离;DAD：230nm。结果血中西地那非线性检测范围为1.5-80.0μg/mL,最小检出限量为5ng,平均回收率：82.45%。结论本检验方法简单、准确、快速,适合于临床检测及刑事案件的快速分析。     

Research of the extraction method of morphine from biological fluids

A solid-phase extraction method of morphine from urine and blood has introduced. The effect of 5 SPE columns, 3 eluents and pH on morphine recovery has been investigated systematically. Derivative GC was used as a method of detection. The result showed that the column and the eluent of such as GDX-301, GDX-403 and C18 chloroform:isopropanol (9:1) had good behaviors to extraction of morphine. When GDX-301 was used as a sorbent, the recovery of morphine from urine was above 90% at pH 9, then went down with the increase of pH. While the recovery from blood was growing with the increase of pH, which reached above 90% in strong alkaline. The extraction method is simple, inexpensive, efficient and reproducible, which provides an effective and practical method to extract morphine and similar illicit drugs from biological fluids.     

Extraction and analysis of flunitrazepam/7-aminoflunitrazepam in blood and urine by LC-PDA and GC-MS using butyl SPE columns

The forensic toxicology community has recognized flunitrazepam and its metabolite (7-aminoflunitrazepam) as compounds of concern for several years. In this procedure, the analytes were extracted from whole blood and urine onto single mode solid phase cartridges (butyl) using nitrazepam as an internal standard. The columns were washed with distilled water and hexane. All three compounds were eluted from the sorbent using an ethyl acetate-methanol solvent mixture. After collection and evaporation of the solvent, the residue was dissolved in A, 0.1% (v/v) aqueous trifluoroacetic acid for HPLC-PDA analysis or B, ethyl acetate for derivatization with pentafluoropropionic anhydride (PFPA) for analysis by gas chromatography-mass spectrometry (selected ion monitoring, SIM). A limit of quantitation for this method using HPLC-PDA was found to be 5 and 1.0 ng mL(-1) by SIM.     

Solid phase extraction method for rapid isolation and clean-up of some synthetic pyrethroid insecticides from human urine and plasma.

A simple and rapid method for the isolation of seven synthetic pyrethroid insecticides (methothrin, fenpropathrin, cyhalothrin, permethrin, cypermethrin, fenvalerate, deltamethrin) with a solid phase extraction (SPE), utilizing Sep-Pak C18 cartridges, from human urine and plasma is presented. The detection of the insecticides was performed using a wide bore capillary gas chromatograph (GC) with flame ionization detection (FID). The insecticide-containing samples mixed with 70% methanol were directly applied to the cartridges and eluted with 2 ml chloroform. The recoveries using the cartridges were between 90-102% for urine and 81-93% for plasma. Mixing samples with 70% methanol prior to extraction, seems very useful for the screening of synthetic pyrethroid insecticides.     

液相色谱-质谱联用法测定人全血中灭多威

目的建立一种简便的测定人全血中灭多威的液相色谱-质谱联用法。方法样品处理采用液-液乙酸乙酯萃取方法。色谱柱为Zorbax SB-C18(2.1mm×50mm,5μm),流动相为乙腈-0.1%甲酸,梯度洗脱,流速为0.5mL/min,柱温40℃。采用ESI离子源,MRM离子方式监测。结果灭多威在0.05~2.0μg/mL浓度范围内线性良好(r0.995)。灭多威的方法回收率均在90%~108%的范围内,日内、日间RSD均小于15%。结论本方法可简单、高效地检测全血中灭多威浓度。     

High performance liquid chromatographic method for the analysis of organophosphorus and carbamate pesticides

A method has been developed for the rapid quantitative analysis of organophosphorous and carbamate pesticides using HPLC. Good separation was obtained among the four major groups of organophosphorus pesticides [i.e. aryl phosphorothionate (methyl parathion), alkyl phosphorothionate (malathion), enolphosphate (phosphomidon, monocrotophos, dichlorvos), heterocyclic phosphorothionates (quinalphos)] and carbamates [viz. Carbaryl (Sevin) and Baygon (Dalf)] with a detection limit of 100 ng for all the pesticides. Separation was measured in terms of capacity factor (k') resolution (R) and selectivity factor (alpha ii). The method described can be used for the analysis of biological samples for the presence of organophosphorus and carbamate pesticides in the cases of poisoning. Recovery studies were made in the blood, lung and liver and found to be 85-97% with reproducibility at greater than 95%.     

Identification of anhydroecgonine ethyl ester in the urine of a drug overdose victim

Toxicological evaluation of postmortem urine collected from a 41-year-old deceased white male detected anhydroecgonine ethyl ester (ethylecgonidine, AEEE), a transesterification product of smoked cocaine co-abused with ethanol. A solid phase extraction (SPE) method was used to extract cocaine, AEEE, and related metabolites from urine. SPE on a 1 mL urine sample from the decedent followed by GC-MS detected AEEE. Other metabolites identified by GC-MS included cocaine, cocaethylene, and anhydroecgonine methyl ester (AEME). To determine whether some or all of the AEEE was artifactually produced in the heated GC injector port, an alternative LC-MS method was developed. LC/MS following SPE found at least 50 ng/mL of AEEE in the extract. The mass fragmentation (MS/MS and MS3) of AEEE detected in the urine was compared to spectra of authentic, synthesized compound. AEEE is a potential additional forensic marker for the co-abuse of smoked cocaine and ethanol.     

体液中常见滥用药物的系统筛选分析

本文建立了体液中常见滥用药物的筛选分析体系.尿液或血液经固相萃取(SPE)或液提取(LLE)后,直接用GC/NPD分析或经TFA、BSTFA衍生化后用GC/MS分析.方法适用于同时分析甲基苯丙胺、MDMA、度冷丁、去甲度冷丁、曲马多、美沙酮、EDDP、可卡因、苯甲酰芽子碱、可待因、安定、氯丙嗪、吗啡、单乙酰吗啡等十四种常见滥用药物及代谢物.SPE法和LLE法回收率分别为66～102%和50～86%,最低检出限为2-5ng/ml尿.涉毒案件的鉴定应用表明该分析方法简便、快速、可靠.     

用固相萃取法提取净化生物检材中拟除虫菊酯类杀虫剂的实验研究

固相萃取法（Sep－PakC18小柱）同时萃取净化生物检材（血浆、尿）中的甲醚菊酯、灭扫利、功夫、二氯苯醚菊酯、安绿宝、速灭杀丁和敌杀死。通过气相色谱氢焰检测器、非极性熔融石英大口径毛细管柱及程序升温色谱条件，得到较好的系统分离，并测定萃取回收率在81％～93％（血浆）和90％～102％之间（尿）。实验证明，用70％甲醇稀释检材并用氯仿洗脱可得到较完全的吸附和最佳回收率。