CYP2D6 and CYP2C19 genotypes and amitriptyline metabolite ratios in a series of medicolegal autopsies

In a series of 202 postmortem toxicology cases, the CYP2D6 and CYP2C19 genes were genotyped, and the concentrations of amitriptyline (AT) and six metabolites were analyzed. The polymorphic CYP2D6 and CYP2C19 genes encode enzymes participating in the metabolism of several potentially toxic drugs, and mutations in these genes may lead to adverse drug reactions, possibly even intoxications. AT was chosen as the substrate of interest because it is mainly metabolized by these enzymes, is considered relatively toxic, and ranks among the major causes of fatal drug poisoning in Finland. Our objective was to evaluate genetically determined interindividual variation in conjunction with metabolite ratios of drugs found in toxicological analysis in a series of medicolegal autopsies. Positive correlations were found between the proportion of trans-hydroxylated metabolites and the number of functional copies of CYP2D6 and between the proportion of demethylated metabolites and the number of functional copies of CYP2C19. None of the accidental or undetermined AT poisonings coincided with the CYP2D6 or CYP2C19 genotype which predicts a poor metabolizer phenotype. However, an unusually high femoral blood concentration of AT, 60mg/l, was found in one suicide case with no functional CYP2D6 genes. Our study shows a concordance of AT metabolite patterns with CYP2D6 and CYP2C19 genotypes in the presence of confounding factors typical for postmortem material. This result demonstrates the feasibility of postmortem pharmacogenetic analysis and supports the dominant role of genes in drug metabolism.     

Postmortem tissue concentrations of venlafaxine

Venlafaxine is a phenethylamine antidepressant which inhibits both serotonin and norepinephrine reuptake and is structurally unrelated to the serotonin reuptake inhibitors (SSRIs). Its major metabolite, O-desmethylvenlafaxine (ODV), also inhibits serotonin reuptake. Although metabolized by the cytochrome P-450 (CYP) system, venlafaxine inhibits CYP 2D6 and 3A4 to a far lesser extent than do the SSRIs. Mechanisms of drug action are reviewed and evaluated in the investigation of 12 fatalities occurring over a 6-month-period where venlafaxine was detected.Venlafaxine and ODV were identified by liquid chromatography-mass spectrometry (LC-MS) using atmospheric pressure ionization (API) electrospray in positive mode following an n-butyl chloride extraction. Postmortem tissue concentrations studied in each of 12 postmortem cases for venlafaxine and ODV, were 0.1-36 and <0.05-3.5mg/l (peripheral blood), <0.05-22 and <0.05-9.9mg/kg (liver), <0.05-10 and <0.05-1.5mg/l (vitreous), <0.05-53 and <0.05-6.8mg/l (bile), <0.05-55 and <0.05-21mg/l (urine), respectively, and 0.1-200mg of venlafaxine in the gastric contents. Venlafaxine was typically present with other drugs, including other antidepressants, alcohol, and benzodiazepines. The potential for interaction with each drug is discussed. Over the 6-month-period of this study, there were no deaths ascribed solely to venlafaxine intoxication.     

Distribution of Venlafaxine,O‐desmethylvenlafaxine,and O‐desmethylvenlafaxine to Venlafaxine Ratio in Postmortem Human Brain Tissue

Venlafaxine (VEN) and its metabolite O‐desmethylvenlafaxine (ODV) inhibit reuptake of serotonin and norepinephrine. This study examines whether VEN is differentially distributed in postmortem brain and examines relationships between brain and femoral blood concentrations from donors prescribed VEN for treatment of depression. Using high‐pressure liquid chromatography‐ultraviolet detection, VEN and ODV concentrations were measured in temporal, occipital, and cerebellar cortex of six postmortem brains. The ODV/VEN ratio was calculated as a relative measure of drug metabolism within each region where higher ratios indicated a greater conversion of VEN to ODV. Compared to the other regions examined, the cerebellum showed decreased VEN (p = 0.056), ODV (p = 0.006), and ODV/VEN (p = 0.027) ratios. In parts per million, VEN was higher in temporal and occipital cortex, but not cerebellum, as compared to femoral blood concentration. These observations suggest that VEN and ODV are differentially distributed in the brain, and metabolism of VEN to ODV may vary across brain regions.     

Pharmacogenomics as an aspect of molecular autopsy for forensic pathology/toxicology: does genotyping CYP 2D6 serve as an adjunct for certifying methadone toxicity?

Pharmacogenomics, applied as an aspect of molecular autopsy, may be used as an adjunct for certifying methadone fatalities. Methadone is metabolized by cytochrome P-450 (CYP) 1A2, 3A4, and 2D6. We hypothesized that methadone toxicity may be partially due to CYP 2D6 *3, *4, and *5 variant alleles, resulting in poor drug metabolism. A retrospective analysis was performed on covariables and risk factors of 21 methadone cases from the Milwaukee County Medical Examiner's Office (1998-2000). PCR genotyping showed: one heterozygous for 2D6*3, two homozygous for 2D6*4, five heterozygous for 2D6*4, and one heterozygous for both 2D6*3 and *4. This limited number of cases showed that the prevalence of poor metabolizer was higher but not significantly different from that of a control group (n = 23) (P > 0.05, Fisher Exact Test). Thus, CYP 2D6 mutations may not yet be directly associated with methadone toxicity. However, pharmacogenomics, complementing other case findings, served as an adjunct in interpreting methadone toxicity of poor and intermediate metabolizers.     

Death of a 10‐Month‐Old Boy After Exposure to Ethylmorphine

Abstract: Ethylmorphine, an opiate that is partially metabolized to morphine, is a common ingredient in antitussive preparations. We present a case where a 10‐month‐old boy was administered ethylmorphine in the evening and found dead in bed the following morning. Postmortem toxicological analyses of heart blood by gas chromatography‐mass spectrometry and liquid chromatography‐mass spectrometry revealed the presence of ethylmorphine and morphine at concentrations of 0.17 μM (0.054 mg/L) and 0.090 μM (0.026 mg/L), respectively. CYP2D6 genotyping showed that the deceased had an extensive metabolizer genotype, signifying a “normal” capacity for metabolizing ethylmorphine to morphine. The autopsy report concluded that death was caused by a combination of opiate‐induced sedation and weakening of respiratory drive, a respiratory infection, and a sleeping position that could have impeded breathing. This is the first case report where the death of an infant has been linked to ethylmorphine ingestion.     

A fatal doxepin poisoning associated with a defective CYP2D6 genotype

It has been suggested that the polymorphism of the CYP2D6 gene can contribute to occurrence of fatal adverse effects. We therefore investigated postmortem toxicology cases of fatal drug poisonings related to CYP2D6 substrates, with the manner of death denoted as accidental or undetermined. CYP2D6 genotypes were determined in 11 consecutive cases with samples available for DNA analysis. A case of fatal doxepin poisoning with an undetermined manner of death was found to coincide with a completely nonfunctional CYP2D6 genotype (*3/*4), indicating a total absence of CYP2D6 enzyme and suggesting a poor metabolizer phenotype. The doxepin concentration was 2.4 mg/L, the concentration of nordoxepin 2.9 mg/L, and the doxepin/nordoxepin ratio 0.83, the lowest found among the 35 nordoxepin-positive postmortem cases analyzed during the same year. No alcohols or other drugs were detected in the case. The CYP2C19 genotype was determined as that of an extensive metabolizer. The high N-desmethylmetabolite concentration is not consistent with acute intoxication. It is therefore probable that the defective genotype has contributed to the death, possibly involving repeated high dosage of doxepin. Our case strongly emphasizes that a pharmacogenetic analysis in postmortem forensic setting may reveal new insight to the cause or manner of death.     

The frequencies of mutated alleles of CYP2D6 gene in a Turkish population

Allele and genotype frequency distribution of CYP2D6*3, *4, *5, *6 and *10 variants were analyzed in blood samples of 100 unrelated healthy individuals by Real-Time PCR. The allele frequencies of CYP2D6*3(A2549del), *4(G1846A), *6(T1707del) and *10(C100T) were 1%, 10%, 2.5% and 14.5% respectively, while allele frequency of CYP2D6*5 was 3% of the subjects tested. Extensive, poor and intermediate metabolizer (EM, PM, IM) genotype frequencies were 63%, 4% and 12%, respectively. CYP2D6 gene duplication was 4%. Our results show that the frequencies of the mutated alleles of CYP2D6 in Turkish populations are similar to some European populations. 4% of Turkish people who have two nonfunctional defective allele are a high risk group and 12.5% of Turkish people who have two decreased functional defective allele or one normal and one non functional defective allele were also in the risk group. Findings of this study demonstrate the importance of genetic variation in drug intoxicants.     

Discrepancy between CYP2D6 phenotype and genotype derived from post-mortem dextromethorphan blood level

OBJECTIVE: To describe the death of a toddler after a therapeutic dose of dextromethorphan and its investigation. STUDY DESIGN: Case report, cytochrome P450 phenotype and genotype determination in the victim and post-mortem drug redistribution study performed in rats. RESULTS: A 20-month Asian male who received 3 mg of dextromethorphan once at 09:00 h and again at 22:00 h was found dead at 04:35 h. Post-mortem examination showed signs of early bronchopneumonia (bacterial cultures were negative); dextromethorphan and dextrorphan blood concentrations taken from the heart cavity were 500 ng/ml (1. 84 micromol/l) and 200 ng/ml (0.78 micromol/l), respectively. Despite the dextromethorphan level being almost 100-fold higher than expected after therapeutic doses, intentional or unintentional overdose was extremely unlikely; other potential causes were investigated. Post-mortem drug redistribution study performed in rats showed that dextromethorphan does not undergo extensive redistribution after death (6+/-5-fold increase) and could not explain the observed dextromethorphan level. The dextromethorphan/dextrorphan concentration ratio of 2.5 found in this toddler was compatible with a slow CYP2D6 metabolizer phenotype. However, the toddler exhibited a fast metabolizer genotype. Potential reasons for this discrepancy are discussed. CONCLUSION: CYP450 phenotypes derived from post-mortem blood levels should be interpreted with caution and preferably confirmed by a genotype analysis.     

Investigation of morphine and morphine glucuronide levels and cytochrome P450 isoenzyme 2D6 genotype in codeine-related deaths

Compared to morphine and morphine-6-glucuronide (M6G), codeine and its other major metabolites codeine-6-glucuronide and norcodeine have weak affinity to opioid μ-receptors. Analgesic effects of codeine are thus largely dependent on metabolic conversion to morphine by the polymorphic cytochrome P450 isoenzyme 2D6 (CYP2D6). How this relates to toxicity and post-mortem whole blood levels is not known. This paper presents a case series of codeine-related deaths where concentrations of morphine, M6G and morphine-3-glucuronide (M3G), as well as CYP2D6 genotype, are taken into account. Post-mortem toxicological specimens from a total of 1444 consecutive forensic autopsy cases in Central Norway were analyzed. Among these, 111 cases with detectable amounts of codeine in femoral blood were identified, of which 34 had femoral blood concentrations exceeding the TIAFT toxicity threshold of 0.3mg/L. Autopsy records of these 34 cases were retrieved and reviewed. In the 34 reviewed cases, there was a large variability in individual morphine to codeine concentration ratios (M/C ratios), and morphine levels could not be predicted from codeine concentrations, even when CYP2D6 genotype was known. 13 cases had codeine concentrations exceeding the TIAFT threshold for possibly lethal serum concentrations (1.6 mg/L). Among these, 8 individuals had morphine concentrations below the toxic threshold according to TIAFT (0.15 mg/L). In one case, morphine as well as M6G and M3G concentrations were below the limit of detection. A comprehensive investigation of codeine-related fatalities should, in addition to a detailed case history, include quantification of morphine and morphine metabolites. CYP2D6 genotyping may be of interest in cases with unexpectedly high or low M/C ratios.     

Interaction of 3,4-methylenedioxymethamphetamine and methamphetamine during metabolism by in vitro human metabolic enzymes and in rats

Illicit amphetamine-type stimulant (ATS) tablets commonly contain one or more active ingredients, which have hallucinogenic and/or stimulant effects. Because components such as 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine (MA) in ATS tablets have similar chemical structures, they could be metabolized by common metabolic enzymes. To investigate potential metabolic interactions of ATS tablet components, we studied the in vitro metabolism of MDMA and MA using human metabolic enzymes. MDMA and MA were mainly metabolized by cytochrome P450 2D6 (CYP2D6) and mutually inhibited the production of their main metabolites. In vivo experiments were also performed using intravenous administration of MDMA, MA, or their mixture to rats. The plasma concentrations of MDMA and MA after co-administration were higher than those after administration of MDMA or MA alone. The results in this study imply that multiple components in ATS tablets can interact to mutually inhibit their metabolism and potentially enhance the toxicity of each component.     

Post-mortem SNP analysis of CYP2D6 gene reveals correlation between genotype and opioid drug (tramadol) metabolite ratios in blood

Tramadol is an opioid drug metabolised in phase I by cytochrome P450 (CYP) enzymes, of which CYP2D6 is mainly responsible for the O-demethylation of tramadol, but is not involved in N-demethylation. Defects in the genes encoding drug metabolising enzymes (DMEs) may lead to adverse drug effects, even to death. To aid interpretation of the forensic toxicology results, we studied how the genetic variation of the CYP2D6 gene is reflected in tramadol metabolite ratios found in post-mortem samples. In 33 Finnish autopsy cases where tramadol was found, we analysed both the CYP2D6 genotype and the concentrations of tramadol and its metabolites O- and N-demethyltramadol. As expected, we found a correlation between the number of functional CYP2D6 alleles and the ratio of tramadol to O-demethyltramadol. We also found a correlation between the number of functional alleles and the ratio of tramadol to N-demethyltramadol. This can be explained by the complementary nature of the two main tramadol demethylation pathways. No known CYP2D6 inhibitors were associated with exceptional metabolic ratios. Furthermore, no accidental tramadol poisonings were associated with a defective CYP2D6 gene. Our results on the tramadol are among the first to demonstrate that genetic variation in drug metabolising enzymes can be analysed in post-mortem blood, and that it correlates well with the parent drug to metabolite ratios. The results also suggest that genetic factors play, in general, a dominant role over other factors in the metabolism of individual drugs.     

Cytochrome P450 2D6 (CYP2D6) genotyping on postmortem blood as a supplementary tool for interpretation of forensic toxicological results

Debrisoquine hydroxylase (CYP2D6) is involved in the metabolism of many toxicologically important drugs. The gene encoding for this enzyme displays a polymorphic distribution in all populations examined. We report a study on 46 cases, where analyses of the CYP2D6 gene were conducted on postmortem femoral blood in order to investigate the occurrence of poor metabolizers (PM). A polymerase chain reaction (PCR) method, designed and routinely used for therapeutic drug monitoring, was employed, only slightly modified. Samples from 22 cases, where the parent drug to metabolite ratio was unexpectedly high were analyzed as well as samples from 24 control cases. Genotyping could be carried out in all but one case. Previous freezing or addition of potassium fluoride as preservative did not prevent analysis. Only one PM (from the control group) was discovered, implying an occurrence of only 2.2% as compared to the reported frequency of approx. 7% in Sweden. Among the extensive metabolizers (EM), however, a number of individuals with mutated genes were identified. Although it seems reasonable to suspect a PM genotype in cases with a high concentration of a drug metabolized by CYP2D6, but without suspicion of acute overdose, our study does not support the opinion that this interpretation pitfall is particularly common. This study rather indicates that drug interactions in EMs constitute a more frequent and important problem.     

Distribution of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) stereoisomers in a fatal poisoning

This communication presents the quantitation and differential distribution of the enantiomers of 3,4-methylenedioxymethamphetamine (MDMA) and its physiologically active metabolite 3,4-methylenedioxyamphetamine (MDA) in a fatal poisoning following insufflation of MDMA, cocaine and heroin. Animal studies have demonstrated the stereoselective pharmacokinetics and neurotoxicity of these compounds; however, enantiomeric distributions have not been reported in humans. Quantitation of MDMA and MDA enantiomer was by gas chromatography/mass spectrometry (GC/MS) following chiral derivatization with N-trifluoroacetyl-l-triproyl chloride (LTPC). The decedents' blood concentration of S(+)-MDMA was slightly less than that of R(−)-MDMA (1.3 vs. 1.6 mg/l, respectively), while the S(+)- and R(−)-MDA blood concentrations were identical (0.8 mg/l). Both primary routes of excretion, bile and urine, had greater concentrations of R(−)-MDMA than the S(+) isomer. These fluids also contained twice the concentration of S(+)-MDA than the R(−)-isomer. These data indicate that S(+)-MDMA is metabolized and eliminated faster than R(−)-MDMA. The results appear to support the findings in animals regarding stereoselective metabolism of MDMA.     

Time-resolved hair analysis of MDMA enantiomers by GC/MS-NCI

The aim of the study was to determine the enantioselective disposition of 3,4-methylenedioxymethamphetamine (MDMA) and other amphetamine-type stimulants (ATS) in segmented hair specimens of self-declared ecstasy abusers, who took part in a double-blind placebo-controlled six-way crossover study during approximately 7 weeks, during which they received a 75 and a 100 mg dose of racemic MDMA twice. Hair specimens were washed and cut into pieces of 2 cm length. After digestion and solid phase extraction, the enantiomers were derivatized with a chiral agent (2S,4R)-N-heptafluorobutyryl-4-heptafluorobutoyloxy-prolyl chloride, developed at the authors laboratory and quantified by gas chromatography coupled to mass spectrometry operating in the negative chemical ionization mode. Most of the hair specimens that were tested positive for MDMA showed a predominance of the (R)-enantiomer. The R/S ratios of MDMA varied between 1.02 and 2.75 and total concentrations ranged from 0.1 to 20.1 ng/mg. The enantiomers of its metabolite 3,4-methylenedioxyamphetamine (MDA) were also quantified in most hair segments. The R/S ratios of MDA varied between 0.60 and 1.60, while the concentrations of the enantiomers ranged from 10 to 160 pg/mg hair. When segmental analysis was performed on single hair specimens, no inversion of the R versus S ratios of MDMA and MDA was observed. The predominance of (R)-MDMA in hair was in accordance with those already published for other matrices. Furthermore, both enantiomers of amphetamine (AM) were also detected in hair segments of four volunteers and the R/S ratios ranged from 1.00 to 1.47.     

The Ratio of 6β‐Hydroxycortisol to Cortisol in Urine as a Measure of Cytochrome P450 3A Activity in Postmortem Cases

Poisoning can occur with chronic accumulation of a drug due to reduced metabolic capacity; conversely, under‐treatment may occur due to an increased metabolic rate. Over half of all drugs are metabolized by the cytochrome P450 3A complex (CYP3A). The activity of CYP3A can be assessed by the urinary ratio of 6β‐hydroxycortisol to cortisol. The aim of this study was to determine the usefulness of this ratio as a postmortem marker for determining whether altered CYP3A enzyme activity occurred prior to death. In a series of 244 postmortem cases, this ratio ranged from 0.014 to 78.6 (median 3.50). The median was significantly higher (5.14) in a subgroup of 28 cases that exhibited the presence of CYP3A‐inducing drugs. In cirrhosis, the median ratio was 1.69. This pointed to a reduced metabolic capacity of CYP3A. Thus, the ratio may constitute a rough indicator of the CYP3A metabolic capacity, which could be of value in special cases.     

Determination of dopamine and dopamine-derived (R)-/(S)-salsolinol and norsalsolinol in various human brain areas using solid-phase extraction and gas chromatography/mass spectrometry

Using a solid-phase extraction procedure and a gas chromatographic-mass spectrometric (GC/MS) method the levels of dopamine and the levels of dopamine-derived salsolinol (SAL) and norsalsolinol (NorSAL) were determined in human brain areas involved in the etiology of alcoholism, parkinsonism and other diseases. The possibility that biosynthesis of salsolinol occurs through a stereospecific enzymatic reaction was considered. Using a two-step derivatization with N-methyl-N-trimethylsilyltrifluoracetamide (MSTFA) and the chiral reagent (R)-(-)-2-phenylbutyryl chloride, baseline separated peaks of (R)- and (S)-SAL were obtained. Both enantiomers were found in human brain samples with no correlations between levels of salsolinol and dopamine. These findings do not support the hypothesis that only an enantio-selective synthesis of (R)-SAL by a putative salsolinol synthase is responsible for the in vivo formation. In our opinion, non-enzymatic formation of salsolinol via the Pictet-Spengler reaction reveals both salsolinol enantiomers and an additional enzymatic synthesis of only (R)-SAL explains the enantiomer ratio (R)-/(S)-SAL of approximately 2.     

Determination of a newly encountered designer drug "p-methoxyethylamphetamine" and its metabolites in human urine and blood

A newly synthesized designer drug, para-methoxyethylamphetamine (PMEA) was unexpectedly detected in the postmortem specimens of fatality involving drug intoxication in 2005, Japan. For unequivocal identification, the isomeric discrimination of PMEA and its positional-isomers was performed by GC/MS with the trifluoroacetylation. In order to prove the intake of PMEA, the characteristic metabolites of PMEA were also identified by GC/MS analysis of the urine specimen with trifluoroacetylation. As a result, para-methoxyamphetamine, para-hydroxyethylamphetamine (POHEA) and para-hydroxyamphetamine were identified as the major metabolites of PMEA. For the quantitative analyses of PMEA and its three metabolites in body fluids, an automated column-switching LC/MS procedure was developed, and applied to the postmortem blood and urine specimens. In this fatal case, blood concentration of PMEA was estimated to be 12.2 microg/mL and this level seemed extremely high in comparison with lethal blood-levels of its analogues, representing acute-intoxication of the victim. Based on the quantitative results, PMEA was found to be extensively metabolized to POHEA via O-demethylation, partly followed by its conjugation.     

基于重组质粒制备STR分型阳性参照物

目的基于重组质粒制备可用于校准法医STR分型的阳性参照物。方法以常用阳性参照物9948人类基因组DNA STR分型为依据,基于重组质粒构建包含CSF1PO、D7S820、TH01等40个常染色体位点,DYS391、DYS522、DYS385a/b等22个Y染色体位点以及性别判定基因座Amelogenin的STR分型阳性参照物。将重组质粒定量、稀释后等比例混合,分别应用于DNATyper~?19、DNATyper~?24、DNATyper~?Y、Amp F?STR~?Identifiler~?Plus以及Power Plex~?18D System五种扩增试剂盒。结果阳性参照物中各重组质粒浓度为0.01pg/μL~0.001pg/μL;应用于Amp F?STR~?Identifiler~?Plus PCR扩增试剂盒,基于重组质粒制备的阳性参照物与人类基因组DNA扩增检测结果差异较小;将此阳性参照物分别应用于不同公司、不同STR基因座的四种STR扩增试剂盒,电泳检测图谱显示各基因座基因型完整,分型正确,峰高相当,基因座间均衡性良好。结论基于重组质粒制备STR分型阳性参照物,是一种可以替代细胞系制备阳性参照物的方法,具有一定的参考价值。基于此方法制备的阳性参照物可适用于市面上常用的STR检验试剂盒,普适性较强,对法医DNA分型检测有一定的实用价值。     

D16S539 microvariant or D2S1338 off-ladder allele? A case report about a range overlapping between two loci

All forensic laboratories routinely use commercial kits and softwares for automated typing; in rare cases genotyping misinterpretations or mislabellings occur. This study refers to the investigation on a D2S1338 off-ladder allele mislabelling observed in DNA profile of murdered woman.The Identifiler^® revealed heterozygosity in the range of D16S539, with a presumptive microvariant allele “14.2”, based on assigned size, while PowerPlex^®16 resulted in a homozygosity of allele “11”. Singleplex amplification of D16S539 locus confirmed homozigosity. D2S1338 locus, the closest to D16S1338 in Identifiler^®, genotyped as homozigote “19”, was singleplex amplified. The off-ladder peak was gel-isolated, sequenced and designed as a rare “11” allele variant [(TGCC)6(TTCC)5]. Genotype was finally designed as D16S539 “11,11” and D2S1338 “11,19”.To avoid genotyping misinterpretations or mislabelling, ambiguous genotypes should be established by two commercial kits at least. Furthermore, off ladder alleles as well as allele microvariants should be assigned by direct sequencing. This issue should be considered in Criminal DNA database requirements, that is still under debate in Italy.     

生物检材中海洛因代谢物分析现状

海洛因在体内极易代谢,其主要的代谢产物为单乙酰吗啡、吗啡等。目前,检测海洛因代谢物的常用生物检材有尿液、血液、毛发等;常用分析方法有薄层色谱法、气相色谱法、高效液相色谱法、气相色谱-质谱联用法、液相色谱-质谱联用法、免疫分析法、毛细管电泳法等。本文参考近年来的文献对生物检材中海洛因代谢物的分析方法作一综述,为法医毒物分析等相关领域的研究提供参考。