The screening of inborn errors of metabolism in sick Chinese infants by tandem mass spectrometry and gas chromatography/mass spectrometry

BackgroundAnalyses of amino acid/acylcarnitines in dried blood spots (DBS) and organic acids in urine are the primary tests for inborn errors of metabolism (IEMs). Automated tandem mass spectrometry (MS/MS) and gas chromatography/mass spectrometry (GC/MS) can rapidly and simultaneously detect numerous metabolic compounds with high precision and sensitivity.MethodsThree thousand four hundred and twenty-nine DBSs and 2781 urine samples were collected from our hospital patients with suspected IEMs, and analyzed for amino acid/acylcarnitines and organic acids by MS/MS and GC/MS, respectively. The results were used in a coincidental survey to determine the efficacy of these methods for the diagnosis of IEMs.ResultsNineteen different types of IEMs were detected in 121 affected cases (1.95% of 6210 samples). There were 66.12% amino acid disorders, 29.75% organic acid disorders and 4.13% with fatty acid oxidation disorders. Conclusions: the sick infants tested in this study had high prevalence rates of neonatal intrahepatic cholestasis, methylmalonic acidemia, hyperphenylalaninemia, tyrosinemia type I, and urea cycle disorders.ConclusionThe combined use of MS/MS and GC/MS is an appropriate tool for screening of IEMs in sick infants.     

Electrospray tandem mass spectrometry for analysis of acylcarnitines in dried postmortem blood specimens collected at autopsy from infants with unexplained cause of death.

BACKGROUND: Deaths from inherited metabolic disorders may remain undiagnosed after postmortem examination and may be classified as sudden infant death syndrome. Tandem mass spectrometry (MS/MS) may reveal disorders of fatty acid oxidation in deaths of previously unknown cause. METHODS: We obtained filter-paper blood from 7058 infants from United States and Canadian Medical Examiners. Acylcarnitine and amino acid profiles were obtained by MS/MS. Specialized interpretation was used to evaluate profiles for disorders of fatty acid, organic acid, and amino acid metabolism. The analyses of postmortem blood specimens were compared with the analyses of bile specimens, newborn blood specimens, and specimens obtained from older infants at risk for metabolic disorders. RESULTS: Results on 66 specimens suggested diagnoses of metabolic disorders. The most frequently detected disorders were medium-chain and very-long-chain acyl-CoA dehydrogenase deficiencies (23 and 9 cases, respectively), glutaric acidemia type I and II deficiencies (3 and 8 cases, respectively), carnitine palmitoyl transferase type II/translocase deficiencies (6 cases), severe carnitine deficiency (4 cases), isovaleric acidemia/2-methylbutyryl-CoA dehydrogenase deficiencies (4 cases), and long-chain hydroxyacyl-CoA dehydrogenase/trifunctional protein deficiencies (4 cases). CONCLUSIONS: Postmortem metabolic screening can explain deaths in infants and children and provide estimates of the number of infant deaths attributable to inborn errors of metabolism. MS/MS is cost-effective for analysis of postmortem specimens and should be considered for routine use by Medical Examiners and pathologists in unexpected/unknown infant and child death.     

气-质联用技术测定尿有机酸方法的建立及在遗传代谢病诊断中的应用

目的 利用气-质联用技术测定尿液中有机酸种类及含量的变化,为先天性遗传代谢病,特别是有机酸代谢紊乱提供新的诊断依据.方法 收集临床高度怀疑为有机酸代谢紊乱的195例患儿的尿液标本,根据肌酐含量取相应体积的尿样和内标,加盐酸羟胺对带羟基的有机酸进行圬化反应生成酮体后,用乙酸乙酯和乙醚萃取有机酸,三甲基硅烷衍生;测定采用Agilent GC/MS 6890/5973i气相质谱仪,选择扫描模式检测,测定质荷比(m/z)范围在50～550 m/z的所有有机酸,数据处理采用Agilent GCMSD ChemStationGl701DA软件.用健康对照样本中加人的内标和阳性对照样本中加入的阳性有机酸进行分析方法的线性范围、精密度、准确性、样本回收率和残留分析.结果 该方法可测定尿液中100余种有机酸,以健康对照者尿样中加入的二甲基丙二酸(MMA)和2-苯基丁酸(2-PA)内标为参考,最低检测极限为2.5～2.8μmol/L;批内和批间变异系数均<10%,样本前处理批间变异系数为11.4%;样品回收率为95%～105%,残留分析<1%,所有参数均符合临床检测的要求.用该方法检测的临床患儿尿样中,发现诊断阳性病例12例,包括6例甲基丙二酸血症、1例丙酸血症、3例酪氨酸血症Ⅰ型、1例枫糖尿病和1例Ketosis病(酮症病).结论本研究建立了气-质联用技术分析测定尿液中有机酸的方法,可用于先天性遗传代谢性疾病的筛查诊断.     

福建省泉州地区新生儿有机酸血症的发病率与疾病谱筛查结果分析

目的 了解福建省泉州地区新生儿有机酸血症(organic academia,OA)筛查的发病率及疾病谱特征。方法 采用串联质谱技术对泉州地区364 545例新生儿干血斑样本进行遗传代谢病筛查,应用高通量测序技术结合Sanger测序法对可疑阳性患儿进行致病基因检测,统计分析泉州及其他地区OA的新生儿筛查数据。结果 364 545例筛查的新生儿中,明确诊断OA患儿39例,OA总发病率为1:9 347。共确诊OA 7种,其中最常见的为2-甲基丁酰辅酶A脱氢酶缺乏症12例(30.8%),其次为戊二酸血症I型7例(17.9%),其余的分别为异丁酰辅酶A脱氢酶缺乏症6例(15.4%)、3-甲基巴豆酰辅酶A脱氢酶缺乏症5例(12.8%)、异戊酸血症4例(10.3%)、甲基丙二酸血症3例(7.7%)和丙酸血症2例(5.1%)。此外,该研究检出4例母源性OA,分别为戊二酸血症I型和3-甲基巴豆酰辅酶A脱氢酶缺乏症各2例。结论 该研究系统回顾分析了泉州地区新生儿OA的筛查概况,泉州地区OA的总发病率较高,OA疾病谱与其他地区不同,最常见的三种OA为2-甲基丁酰辅酶A 脱氢酶缺乏症、戊二酸血症I型和异丁酰辅酶A脱氢酶缺乏症。OA临床异质性大,发病率及疾病谱的阐明将为该地区的新生儿筛查提供科学依据与指导。     

Improvement of sample throughput using fast gas chromatography mass-spectrometry for biochemical diagnosis of organic acid disorders

BACKGROUND: Gas chromatograph mass-spectrometric (GC/MS) method of analysis for urinary organic acids is used for the diagnosis of a variety of metabolic disorders. The method is time-consuming and does not allow for improvements in sample throughput. Although the sample preparation and the data processing have been improved, the long GC/MS analysis time still remains to be problematic. METHODS: The fast-GC/MS method, which utilizes a short microbore capillary GC column and fast temperature programming, was applied to the analysis for urinary organic acids. Urine samples obtained from 15 patients with 9 different disorders and 16 healthy controls were analyzed using conventional GC/MS and fast-GC/MS. RESULTS: Analysis cycle time was shortened from 1 h to 15 min. The automated data system uses retention indices determined by conventional-GC/MS for the identification of 134 organic acids. These retention indices can also be used in data obtained by fast-GC/MS. New fast-GC/MS method with the automated data system gave the same diagnostic results as conventional-GC/MS except for 1 healthy control. CONCLUSIONS: The combined system of fast-GC/MS and the automated data system will be powerful tools in clinical laboratories due to increased sample throughput and reduced analysis costs.     

高危新生儿遗传代谢病临床病因学分析

目的 初步研究新生儿重症监护室(NICU)先天性遗传代谢病(IEM)高危新生儿的临床病因学.方法 应用气相色谱-质谱联用分析法(GC/MS)对100 例临床IEM 高危新生儿进行新鲜晨尿有机酸分析,并查血常规、肝肾功能、乳酸、丙酮酸、β-羟丁酸、血氨和同型半胱氨酸,其中24 例患儿尿有机酸分析结果阳性,临床拟诊为IEM,对临床拟诊为IEM 的24 例患儿进行1 ～2 个疗程的治疗,之后复查GC/MS 尿有机酸分析.结果 24 例临床拟诊为IEM 的患儿12 例确诊为IEM,其中丙酮酸血症、酪氨酸血症和同型半胱氨酸血症各2 例,甲基丙二酸尿症、戊二酸血症Ⅱ型、乳糖不耐症、高甲硫氨酸血症、β-酮硫解酶缺乏症和鸟氨酸氨甲酰转移酶缺乏症各1 例,均呈常染色体隐性遗传.12 例IEM 患儿的临床表现各不相同,其中血管病变3 例(微血栓形成1 例和脑实质内出血2 例),新生儿惊厥和复发性代谢性酸中毒各2 例,新生儿猝死、难治性低血糖、顽固性腹泻、遗传相关性高胆红素血症和重症肺炎各1 例.12 例IEM 患儿的疾病极期,100%出现高氨血症,83%出现丙酮酸血症,67%出现肾损害和代谢性酸中毒,50%出现肝损害,42%出现血液系统损害.结论 高危新生儿IEM 临床病因复杂,随着新技术的发展,新生儿IEM 疾病谱不断扩大,进一步揭示了高危新生儿病因,为临床诊治提供依据.     

串联质谱和高效液相色谱-串联质谱二次筛查联合应用于新生儿MMA筛查

目的探讨串联质谱和高效液相色谱-串联质谱二次筛查联合应用在甲基丙二酸血症(MMA)中的筛查价值。方法收集新生儿串联质谱初筛结果中C3、C3/C2、C3/C0单一或多个指标异常的新生儿干血滤纸片标本,用高效液相色谱-串联质谱的方法定量检测原始血片中甲基丙二酸、甲基枸橼酸和高半胱氨酸,对二次筛查后疑似阳性的新生儿进行召回复查,并进行尿气相色谱/质谱检测。临床诊断患儿进一步予以基因检测进行确诊。结果共收集423例C3、C3/C2、C3/C0单一或多个指标异常的新生儿筛查标本,初筛阳性率约为1%,行联合筛查检测结果发现8例标本中甲基丙二酸和同型半胱氨酸表达水平明显升高,召回复查尿气相色谱质谱提示甲基丙二酸轻度升高。结论串联质谱和高效液相色谱-串联质谱联合应用可以提高新生儿MMA筛查的阳性预测值、降低假阳性率,在新生儿遗传代谢病筛查中具有重要价值。     

Quantification of glutaric acid by isotope dilution mass spectrometry for patients with glutaric acidemia type I: selected ion monitoring vs. selected ion storage.

An isotope dilution mass spectrometric assay for the quantification of glutaric acid in urine and serum samples was developed. The performance of a quadrupole mass filter (QMF) gas chromatography-mass spectrometry (GC-MS) instrument, operated in the selected ion monitoring mode, and a quadrupole ion trap (QIT) GC/MS instrument, operated in the selected ion storage mode, was compared. Both instruments gave linear standard curves with glutaric acid concentrations between 0.19 and 3.8 microM. The average coefficients of correlation were 0.9998 and 0.9993 for the QMF and the QIT system, respectively. There was good agreement between the glutaric acid concentrations measured with the two instruments. The run-to-run precision was between 1.2 and 3.7% and between 6.2 and 8.6%, the average recovery of glutaric acid in urine and serum samples was 96 and 103% with the QMF and QIT instrument, respectively. We conclude that although the QMF has a slightly better performance, both instruments can be used to reliably measure glutaric acid concentrations from urine and serum patient samples.     

Studies of urinary organic acid profiles of a patient with dihydrolipoyl dehydrogenase deficiency

Using gas chromatography-mass spectrometry (GC/MS), urinary organic acid profile studies were carried out on a patient with dihydrolipoyl dehydrogenase (E3) deficiency. Elevated levels of 2-hydroxyglutaric acid, 2-hydroxyisocaproic acid and 2-oxoisocaproic acid were observed in addition to lactic acid, 2-oxoglutaric acid, 2-hydroxyisovaleric acid and 2-hydroxybutyric acid previously described in patients with E3 deficiency. The 2-oxoglutaric acid levels were significantly lowered after branched-chain amino acid restriction. In an acute period, the patient was slightly ketoacidotic and excreted larger amounts of 2-oxoglutaric acid and lactic acid than in a static period. It was shown that, prior to confirmatory enzyme studies, patients with E3 deficiency who were suspected to have atypical maple syrup urine disease or chronic lactic acidosis can be rapidly identified by GC/MS analysis of urinary acids.     

Use of proton nuclear magnetic resonance spectroscopy in detection and study of organic acidurias

We used high-resolution proton nuclear magnetic resonance spectroscopy to detect, identify, and study the major normal and abnormal organic acid metabolites in urine from patients with propionic acidemia, methylmalonic aciduria, branched-chain ketoaciduria, isovaleric acidemia, and glutaric aciduria type I. Characteristic and diagnostic spectra were obtained at 400 MHz for each disorder in all the patients studied and neutral and basic compounds, including amino acids and acylcarnitines, were also detected. The technique is rapid (10 min) and requires small samples (0.5 mL) and no preliminary extraction or derivative preparation. We believe that it is particularly suitable for the rapid and acute diagnosis of inborn errors of metabolism, especially the organic acidurias, and for acute pediatric clinical care, when rapid monitoring of major metabolic alterations is required in a time scale suitable to influence directly and immediately the therapy of the patients concerned.     

Diagnostic challenges of aminoacidopathies and organic acidemias in a developing country: A twelve-year experience

Background

Diagnosis of aminoacidopathies and organic acidemias constitutes a real challenge in a developing country with high consanguinity rate and no systematic newborn screening. We report a twelve-year experience with the identification of these disorders in Lebanon, based on their clinical and biochemical profiles.

Methods

In this retrospective study, we reviewed clinical presentation and biochemical investigations of 294 patients. Traditional chromatographic methods were used for analyses. Findings were linked to the identified disorders.

Results

Out of 2921 patients, presenting to our metabolic program with neurological, digestive, family history and/or other symptoms suggestive of aminoacidopathy or organic acidemia, 294 patients were included with confirmed amino or organic acid disorder. The overall analytical yield was 10%. Aminoacidopathies were three-fold higher than organic acidemias. Phenylketonuria and methylmalonic acidemia were the most frequent. The majority of patients (79%) were symptomatic (median age: 14 months, range: 1 day–44 years), mainly with neurological manifestations (87%). Intellectual disability was mostly due to phenylketonuria (73%). Chronic liver failure was frequent in maple syrup urine disease (53%). Plasma amino and urine organic acid chromatography were diagnostic in 8.8% and 3.9% of analyzed cases, respectively. Change in chromatographic technique from reversed-phase to ion-exchange enhanced the detection of many aminoacidopathies.

Conclusions

In the absence of newborn screening, the majority of aminoacidopathy and organic acidemia cases are still diagnosed clinically. This study emphasizes the importance of clinical awareness and accurate biochemical analyses as key tools for diagnosis in countries like ours, and the necessity for a comprehensive national newborn screening program.     

Tandem mass spectrometric analysis for amino, organic, and fatty acid disorders in newborn dried blood spots: a two-year summary from the New England Newborn Screening Program.

BACKGROUND: Tandem mass spectrometry (MS/MS) is rapidly being adopted by newborn screening programs to screen dried blood spots for >20 markers of disease in a single assay. Limited information is available for setting the marker cutoffs and for the resulting positive predictive values. METHODS: We screened >160 000 newborns by MS/MS. The markers were extracted from blood spots into a methanol solution with deuterium-labeled internal standards and then were derivatized before analysis by MS/MS. Multiple reaction monitoring of each sample for the markers of interest was accomplished in approximately 1.9 min. Cutoffs for each marker were set at 6-13 SD above the population mean. RESULTS: We identified 22 babies with amino acid disorders (7 phenylketonuria, 11 hyperphenylalaninemia, 1 maple syrup urine disease, 1 hypermethioninemia, 1 arginosuccinate lyase deficiency, and 1 argininemia) and 20 infants with fatty and organic acid disorders (10 medium-chain acyl-CoA dehydrogenase deficiencies, 5 presumptive short-chain acyl-CoA dehydrogenase deficiencies, 2 propionic acidemias, 1 carnitine palmitoyltransferase II deficiency, 1 methylcrotonyl-CoA carboxylase deficiency, and 1 presumptive very-long chain acyl-CoA dehydrogenase deficiency). Approximately 0.3% of all newborns screened were flagged for either amino acid or acylcarnitine markers; approximately one-half of all the flagged infants were from the 5% of newborns who required neonatal intensive care or had birth weights <1500 g. CONCLUSIONS: In screening for 23 metabolic disorders by MS/MS, an mean positive predictive value of 8% can be achieved when using cutoffs for individual markers determined empirically on newborns.     

Glutaric acidemia type II patient with thalassemia minor and novel electron transfer flavoprotein-A gene mutations: A case report and review of literature

Glutaric acidemia type II (GAII), also known as multiple acyl-CoA dehydrogenase deficiency, is an autosomal recessive inborn error of amino acid and fatty acid metabolism. We report a case of GAII with novel electron transfer flavoprotein (ETF)-A mutations in a 2-year-old female with thalassemia minor. The patient developed an episode of hypoglycemia and hypotonicity on the postnatal first day. Laboratory investigations revealed elevations of multiple acyl carnitines indicating glutaric acidemia type II in newborn screening analysis. Urinary organic acids were evaluated for the confirmation and revealed a high glutaric acid excretion. Genetic analysis revealed two novel mutations in the ETF-A gene, which are considered to be compound heterozygote. At the 8 mo of life ketone therapy was added, which significantly increased the neuromotor development. The patient had been closely followed for two years with carnitine, riboflavin, coenzyme Q10, and ketone supplementation in addition to a high carbohydrate diet. Although the patient had comorbidity like thalassemia minor, her neuromotor development was normal for her age and had no major health problems. This specific case expands the previously reported spectrum of this disease.     

Urine 4-heptanone: a beta-oxidation product of 2-ethylhexanoic acid from plasticisers

4-Heptanone is a common volatile constituent of human urine and is of unknown origin. We hypothesised that it arises from in vivo beta-oxidation of 2-ethylhexanoic acid (EHA) from plasticisers, similar to formation of 3-heptanone from valproic acid. We investigated urine from individuals with normal and increased plasticiser exposure. Using GC/MS, solvent-extracted organic acids were analysed as trimethylsilyl (TMS) derivatives and heptanone with headspace solid-phase microextraction. We identified 3-oxo-2-ethylhexanoic acid, the beta-oxidation product of EHA, as an enol in all samples. This is the first report of its TMS mass spectrum. We also found 2-ethyl-1,6-hexanedioic acid and 5-hydroxyEHA, omega- and omega-1-oxidation products of EHA, respectively, and 2-ethylhexanoylglucuronide, but only in trace amounts in some plasticiser samples. These compounds have not been reported in human urine, nor has the TMS mass spectrum of 5-hydroxyEHA. The median concentrations of 3-oxoethylhexanoic acid and total 4-heptanone of seven plasticiser samples were around 30--175-fold higher than normal samples. 4-Heptanone was barely detectable and 3-oxoethylhexanoic acid was not increased in an eighth plasticiser sample, from a baby with deficiency of 2-methylbranched-chain acyl-CoA dehydrogenase. beta-Oxidation is a major catabolic pathway of EHA in man, and might be involved in the metabolism of other branched-chain drugs and environmental pollutants.     

Screening of newborns and high-risk group of children for inborn metabolic disorders using tandem mass spectrometry in South Korea: a three-year report

BACKGROUND: Mass screening using tandem mass spectrometry(MS/MS) was initiated to determine if the incidence of metabolic disorder is sufficiently high to meet the criteria for newborn screening, and whether or not early medical intervention might be beneficial to the patients. METHODS: Newborns and children in a high-risk group were screened using MS/MS from April 2001 to March 2004. Blood spots of newborns were collected between 48 and 72 h after birth. The dried blood spots was extracted with 150 microl of methanol, and analyzed by MS/MS. RESULTS: From April 2001 to March 2004, 79,179 newborns were screened for organic, amino and fatty acid metabolism disorders, which account for approximately 5.4% of annual births in South Korea. Twenty-eight newborns were diagnosed with one of the metabolic disorders and the collective estimated prevalence amounted to 1 in 2800 with a sensitivity of 97.67%, a specificity of 99.28%, a recall rate of 0.05%, and a positive predictive value of 6.38%. 6795 infants/children at high risk were screened and 20 were confirmed to have metabolic disorders. CONCLUSION: The collective total prevalence of 1:2800 in newborns indicates an underestimation of the incidence of metabolic disorders prior to implementing MS/MS screening in South Korea.     

Validation of an ESI-MS/MS screening method for acylcarnitine profiling in urine specimens of neonates,children, adolescents and adults

BACKGROUND: Acylcarnitine (AC) profiling in dried blood spots by means of electrospray ionisation tandem mass spectrometry (ESI-MS/MS) has proven to be a useful method in neonatal screening, able to detect inborn errors of fatty acid oxidation, amino acid, organic acid and carnitine metabolism. Furthermore, this method is becoming increasingly applied in selective screening and in prenatal and postmortal diagnostics of inborn metabolic disorders, where urine is commonly used as specimen of interest. We therefore developed and validated a butylation method of acylcarnitine profiling in urine by ESI-MS/MS without previous chromatographic separation. METHODS: Random urine specimens were used for investigation of the analytical imprecision of the method. Recovery, precision and linearity were determined using methanolic standard solutions of free carnitine, octanoylcarnitine and palmitoylcarnitine at various concentrations. RESULTS: The mean coefficients of variation of within-run and run-to-run analysis of these analytes were found between 10% and 20% and demonstrated that the method fulfills the analytical requirements within the relevant ranges of concentration. Creatinine-related and age-related reference values of free carnitine and the ACs (C2-C18) were established. The definite discrimination was possible between patients with fatty acid oxidation disorders, organic acidurias, and healthy controls. The AC profiles from patients with various specific disorders were diagnostically helpful during acute deterioration and even during conditions of well-compensated metabolic state. CONCLUSION: The method used in this study is suitable both for selective screening and for confirmation of diagnosis with the advantage of high-throughput quantitative measurement.     

Automated metabolic profiling and interpretation of GC/MS data for organic acidemia screening: a personal computer-based system

We have developed a personal computer-based system designed for automated metabolic profiling of urinary organic acids by gas chromatography-mass spectrometry (GC/MS) and data interpretation for organic acidemia screening. For the automated profiling, we compiled retention indices, two target ions and their intensity ratio for 126 urinary metabolites. Metabolites above the cut-off values were flagged as abnormal compounds. The data interpretation was based on combination of the flagged metabolites. Diagnostic or index metabolites were categorized into three groups, "AND," "OR" and "NO," and compiled for each disorder to improve the specificity of the diagnosis. Groups "AND" and "OR" comprised essential and optional compounds, respectively, which and both to reach a specific diagnosis. Group "NO" comprised metabolites that must be absent to make a definite diagnosis. We tested this system by analyzing urine specimens from 48 patients previously diagnosed as having organic acidemias. In all cases, the diagnostic metabolites were identified and each correct diagnosis could be found among the possible diseases suggested by the system. Hence, with this simplified automated system, more people will be able to participate extensively in any screening programs using GC/MS.     

Tandem mass spectrometry in discovery of disorders of the metabolome

Genetic disorders of amino acid and fatty acid metabolism can be detected with tandem mass spectrometry (MS/MS). MS/MS screening of mice subjected to chemical mutagenesis (see the related article beginning on page 434) defined a new disorder of branched-chain amino acid metabolism resembling human maple syrup urine disease. This approach has general application to the discovery of gene function in developmental and metabolic disorders.     

Identification of glutarylcarnitine in glutaric aciduria type 1 by carboxylic acid analyzer with an ODS reverse-phase column

A technique for the identification of glutarylcarnitine in urine from a patient with glutaric aciduria type 1 is described. The patient's urine sample was partially purified using an anion exchange column and analyzed by a carboxylic acid analyzer fitted with an ODS reverse-phase column. The chromatogram of the patient's urine sample revealed 3 different peaks, which corresponded respectively to those of carnitine with amino acids, acetylcarnitine and glutarylcarnitine. Following hydrolysis of the sample, the chromatogram had no peaks of acetylcarnitine and glutarylcarnitine but had remarkably amplified peaks of carnitine, acetic acid and glutaric acid. The eluent fraction of glutarylcarnitine from the non-hydrolyzed sample was hydrolyzed and analyzed again. It no longer had the glutarylcarnitine peak on the chromatogram, but had only two separate peaks of carnitine and glutaric acid. This technique simplifies the identification of glutarylcarnitine, in that it requires only removal of organic acids for preparation of samples, and does not require radioisotope or mass spectrometry.     

Rapid drug screening using Toxi-Lab extraction followed by capillary gas chromatography/mass spectroscopy

We report here a method of analyzing drugs in body fluids by gas chromatography/mass spectroscopy (GC/MS) without the necessity for derivatization. Specimens (urine and serum) were extracted one time using Toxi-Lab extraction tubes. The organic extract was evaporated to dryness, taken up in methanol, and injected directly onto a Hewlett-Packard 5995B GC/MS equipped with a 20-m, 5% phenylmethylsilicone capillary column. Most drugs of clinical interest eluted in 1-10 min and were identified by their mass spectra. Amphetamines were readily distinguished from other sympathomimetic amines; cocaine and its principal metabolite ecgonine methyl ester were readily detected without derivatization. We conclude that the combination of Toxi-Lab extraction and capillary GC/MS analysis provided a rapid, versatile, and efficient method for screening and/or confirming the presence of drugs in biological specimens.