Direct and rapid characterization of illicit drugs in adulterated samples using thermal desorption electrospray ionization mass spectrometry

Foods and drinks have been adulterated with illicit drugs to facilitate criminal activities. Unfortunately, conventional analytical methods are incapable of rapidly characterizing these drugs in samples, as serious interferences from sample matrices must be removed through tedious and time-consuming pretreatment. Ambient ionization mass spectrometry (AMS) generally does not require sample pretreatment and is thus a suitable tool for directly and rapidly detecting illicit drugs in samples in different physical states. In this study, thermal desorption electrospray ionization mass spectrometry (TD-ESI/MS), an AMS technique, was utilized to efficiently characterize illicit drugs spiked in samples including drinks, powders, and jelly candies. To perform sensitive analysis, the mass analyzer was operated in multiple reaction monitoring mode to monitor the molecular and fragment ions of the target analytes. The time required to complete a typical TD-ESI/MS analysis was less than 30 s. The limits of detection (LODs) for illicit drugs were found to be 100 ppb in drinks, 100–1000 ppb in instant powders, and 1.3–6.5 ng/mm² on stamp surfaces. FM2 and nitrazepam laced in the inner layer of a jelly candy were detected by TD-ESI/MS, showcasing the advantage of the technique for direct and rapid analysis as opposed to conventional methods.     

Application of electrospray ionization product ion spectra for identification with atmospheric pressure matrix‐assisted laser desorption/ionization mass spectrometry – a case study with seized drugs

Product ion spectra obtained with liquid chromatography‐electrospray ionization tandem mass spectrometry (LC‐ESI/MS/MS) were applied to the identification of seized drug samples from atmospheric pressure matrix‐assisted laser desorption/ionization product ion spectra (AP‐MALDI‐MS/MS spectra). Data acquisition was performed in the information‐dependent acquisition (IDA) mode, and the substance identification was based on a spectral library previously created with LC‐ESI/MS/MS using protonated molecules as precursor ions. A total of 39 seized drug samples were analyzed with both AP‐MALDI and LC‐ESI techniques using the same triple‐quadrupole instrument (AB Sciex 4000QTRAP). The study shows that ESI‐MS/MS spectra can be directly utilized in AP‐MALDI‐MS/MS measurements as the average fit and purity score percentages with AP‐MALDI were 90% and 85%, respectively, being similar to or even better than those obtained with the reference LC/ESI‐MS/MS method. This fact enables the possibility to use large ESI spectral libraries, not only to ESI analyses but also to analyses with other ionization techniques which produce protonated molecules as the base peak. The data obtained shows that spectral library search works also for analytical techniques which produce multi‐component mass spectra, such as AP‐MALDI, unless isobaric compounds are encountered. The spectral library search was successfully applied to rapid identification of confiscated drugs by AP‐MALDI‐IDA‐MS/MS. Copyright © 2012 John Wiley & Sons, Ltd.     

抗癌药与DNA相互作用的电喷雾质谱研究

为了进一步阐明抗癌药与DNA结合的序列选择性和结合本质，用电喷雾质谱方法研究了抗癌药与DNA的相互作用，这些药物包括小沟结合剂（偏端霉素A，DM和纺锤霉素，NP）和嵌入剂（米托蒽醌，MT）。DM与AT富有的DNA主要形成2∶1的特异性复合物，NP只形成1∶1的特异性复合物；MT倾向与GC富有的DNA特异性结合。另外，DM与带5个A/T碱基小沟长度的DNA几乎以2∶1结合，而与带3个A/T碱基的DNA未见结合，而NP与带4个A/T碱基的DNA结合能力最强。MT还与6-mer DNA形成了1∶1特异性复合物。竞争结合实验证明，DM和NP与AT富有的DNA的键合顺序为NP>DM。这些结果为深入研究抗癌药物的作用机制和改进目标药物结构提供了依据。     

Applicability of ultra‐high performance liquid chromatography‐quadrupole‐time of flight mass spectrometry for cocaine profiling

For the first time in China, the chemical profiling of cocaine specimens was performed at the National Narcotics Laboratory. An ultra‐high performance liquid chromatography‐quadrupole‐time of flight mass spectrometry (UHPLC‐QTOF‐MS) method was developed and validated for simultaneous analysis of 14 cocaine alkaloids and 5 main adulterants. Among them, ecgonine methyl ester, ecgonine, benzoylecgonine, and norcocaine were identified by comparing with the standard materials; tropacocaine, 3,4,5‐trimethoxycocaine, cis‐/trans‐cinnamoylcocaine were tentatively identified based on the exact masses of protonated molecules and product ions; six unidentified alkaloids of 182/1.47, 316/9.54, 659/9.85, 316/9.87, 420/10.34, and 420/10.85 were marked with ‘extracted mass/retention time’ for convenience. Minimum sample preparation and analysis time were required, which was suitable for routine analysis. Based on the semi‐quantitative data set of 14 alkaloid impurities in 131 linked/unlinked cocaine samples, 50 combinations of pretreatment methods and distance/correlation measurements were tested for their potential discrimination power for cocaine profiling, and Logarithm/Pearson exhibited the best result. After hierarchical cluster analysis (HCA), 183 cocaine samples collected from 2011 to 2015 were classified into 7 major groups. Moreover, 37 groups of linked samples were found within and between provinces, which provide intelligence for the case connection and revealing of the distribution networks. Our results highlighted the practical utilities of drug profiling, especially to support the investigation through operational intelligence and to improve the knowledge related to the drug trafficking through strategic intelligence. Copyright © 2016 John Wiley & Sons, Ltd.     

Analysis of ethyl glucuronide in hair samples by liquid chromatography‐electrospray ionization–tandem mass spectrometry (LC‐ESI‐MS/MS)

Many different biomarkers can be used to evaluate ethanol intake. Ethyl glucuronide (EtG) is a direct phase II and minor metabolite of ethanol formed through the UDP‐glucuronosyl transferase‐catalyzed conjugation of ethanol with glucuronic acid. Its investigation is of interest in both clinical and forensic contexts because of the wide window of detection. A sensitive LC‐MS/MS procedure has been developed and fully validated according to the guidelines of forensic toxicology for the analysis of EtG in hair. Sample preparation and chromatographic separation were thoroughly optimized. The analysis was performed in the multiple reaction monitoring mode using the transitions m/z 221 → 203 (for the quantification) and 221 → 85 or 75 (for the qualification) for EtG, and m/z 226 → 208 (for quantification) and 226 → 75 or 85 (for qualification) for EtG‐D5, used as the internal standard. Analyses were carried out using an Inertsil ODS‐3 column (100 × 3 mm i.d., 3 µm particle size) and a mobile phase composed of formic acid and acetonitrile. Various SPE cartridges and solvents were tested in order to obtain the highest recoveries and cleanest extracts. The assay linearity of EtG was confirmed over the range from 20 to 2500 pg mg^?1, with a coefficient of determination (R²) above 0.99. The lower limit of quantitation (LLOQ) was 20 pg mg^?1 and the limit of detection was 10 pg mg^?1. Intra‐ and inter‐day assays were less than 15% except at the LLOQ (20%). The analytical method was applied to 72 post‐mortem hair samples. EtG concentration in the hair ranged from 0 to 653 pg mg^?1 hair. Copyright © 2012 John Wiley & Sons, Ltd.     

Rapid identification of herbal toxins using electrospray laser desorption ionization mass spectrometry for emergency care

The unintentional ingestion of toxic compounds in herbs is not uncommon in many parts of the world. To provide timely and life-saving care in the emergency department, it is essential to develop a point-of-care analytical method that can rapidly identify these toxins in herbs. Since electrospray laser desorption ionization mass spectrometry (ELDI/MS) has been successfully used to characterize non-volatile chemical compounds without sample preparation, it was used to identify toxic herbal compounds in this study. The herbal toxins were collected either by sweeping a metallic probe across the surface of a freshly cut herb section or by directly sampling extracts of ground herbal powder. The analytes on the probe were then desorbed, ionized and detected using ELDI/MS, wherein analysis of the herbal toxins was completed within 30 s. This approach allows for the rapid morphological recognition of herbs and early point-of-care identification of herbal toxins for emergency management and is promising in providing important toxicological information to ensure appropriate medical treatment.     

Direct analysis of cannabis samples by desorption atmospheric pressure photoionization‐mass spectrometry

Fast analysis of cannabis samples without prior sample preparation or chromatography was performed using desorption atmospheric pressure photoionization‐mass spectrometry (DAPPI‐MS). The MS² spectra of the molecular ions of tetrahydrocannabinol (THC) and cannabidiol (CBD) formed in DAPPI‐MS showed distinct product ions, unlike the protonated molecules formed with other ambient mass spectrometry techniques, making possible the reliable identification of THC from cannabis samples. Copyright © 2012 John Wiley & Sons, Ltd.     

Profiling of synthesis‐related impurities of the synthetic cannabinoid Cumyl‐5F‐PINACA in seized samples of e‐liquids via multivariate analysis of UHPLC−MSn data

Vaping of synthetic cannabinoids via e‐cigarettes is growing in popularity. In the present study, we tentatively identified 12 by‐products found in a pure sample of the synthetic cannabinoid Cumyl‐5F‐PINACA (1‐(5‐fluoropentyl)‐N‐(2‐phenylpropan‐2‐yl)‐1H‐indazole‐3‐carboxamide), a prevalent new psychoactive substance (NPS) in e‐liquids, via high‐resolution mass spectrometry fragmentation experiments (HRMS/MS). Furthermore, we developed a procedure to reproducibly extract this synthetic cannabinoid and related by‐products from an e‐liquid matrix via chloroform and water. The extracts were submitted to flash chromatography (F‐LC) to isolate the by‐products from the main component. The chromatographic impurity signature was subsequently assessed by ultra‐high‐performance liquid chromatography coupled to mass spectrometry (UHPLC–MS) and evaluated by automated integration. The complete sample preparation sequence (F‐LC + UHPLC–MS) was validated by comparing the semi‐quantitative signal integrals of the chromatographic impurity signatures of five self‐made e‐liquids with varying concentrations of Cumyl‐5F‐PINACA [0.1, 0.2, 0.5, 0.7 and 1.0% (w/w)], giving an average relative standard deviation of 6.2% for triplicate measurements of preparations of the same concentration and 10.5% between the measurements of the five preparations with different concentrations. Lastly, the chromatographic signatures of 14 e‐liquid samples containing Cumyl‐5F‐PINACA from police seizures and Internet test purchases were evaluated via hierarchical cluster analysis for potential links. For the e‐liquid samples originating from test purchases, it was found that the date of purchase, the identity of the online shop, and the brand name are the critical factors for clustering of samples.     

Differentiation of South American crack and domestic (US) crack cocaine via headspace‐gas chromatography/mass spectrometry

South American ‘crack’ cocaine, produced directly from coca leaf, can be distinguished from US domestically produced crack on the basis of occluded solvent profiles. In addition, analysis of domestically produced crack indicates the solvents that were used for cocaine hydrochloride (HCl) processing in South America. Samples of cocaine base (N=3) from South America and cocaine from the USA (N=157 base, N=88 HCl) were analyzed by headspace‐gas chromatography‐mass spectrometry (HS‐GC‐MS) to determine their solvent profiles. Each cocaine HCl sample was then converted to crack cocaine using the traditional crack production method and re‐examined by HS‐GC‐MS. The resulting occluded solvent profiles were then compared to their original HCl solvent profiles. Analysis of the corresponding crack samples confirmed the same primary processing solvents found in the original HCl samples, but at reduced levels. Domestically seized crack samples also contained reduced levels of base‐to‐HCl conversion solvents. In contrast, analysis of South American crack samples confirmed the presence of low to high boiling hydrocarbons and no base‐to‐HCl conversion solvents. The presented study showed analysis of crack cocaine samples provides data on which processing solvents were originally utilized in the production of cocaine HCl in South America, prior to conversion to crack cocaine. Determination of processing solvents provides valuable information to the counter‐drug intelligence community and assists the law enforcement community in determining cocaine distribution and trafficking routes throughout the world. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.     

胸腺五肽一级结构的电喷雾质谱分析

目的测定胸腺五肽的相对分子质量及其一级结构。方法应用电喷雾质谱法(ESIMS)及源内碰撞诱导解离技术对胸腺五肽进行测定,根据其典型碎片离子确证其氨基酸序列及相对分子质量。结果测得胸腺五肽准分子离子峰(M+H)+m/z680.3及(M+Na)+m/z702.2,(M+2Na-H)+m/z724.3及(M+3Na-2H)+m/z746.2,表明胸腺五肽的相对分子质量为679.4,与理论值一致。结论胸腺五肽的相对分子质量及一级结构与理论值相符。     

Quantification of cocaine and cocaine metabolites in dried blood spots from a controlled administration study using liquid chromatography–tandem mass spectrometry

Cocaine is a common illicit stimulant and is mainly metabolized by hydrolysis to benzoylecgonine (BE) and ecgonine methyl ester (EME), but also to minor metabolites like norcocaine, or hydroxy‐BE. When ethanol is present, cocaethylene is formed. Dried blood spot (DBS) sampling is a minimally invasive microsampling technique with possible advantages for analyte stability and ease of storage, making it an attractive matrix in forensic and clinical settings. We developed a liquid chromatography–tandem mass spectrometry‐based (LC–MS/MS) method for quantifying cocaine, BE, EME, norcocaine, hydroxy‐BE, and cocaethylene in DBS. Six‐mm punches were extracted with aqueous buffer followed by protein precipitation, evaporation and reconstitution in mobile phase. Separation was achieved on a Polar‐RP column (Phenomenex) in a 6‐minute gradient including baseline‐separation of norcocaine and BE. For MS detection, a QTRAP 5500 (Sciex) was used in positive electrospray ionization (ESI) multiple reaction monitoring (MRM) mode. The method was validated for selectivity, sensitivity [lower limited of quantification (LLOQ) 1.0–5.0 ng/mL], imprecision (≤13.4%, ≤19.6% at LLOQ), accuracy (≤ ± 14.9%), matrix effects, extraction efficiency (≥20.9%), hematocrit effect, volume spotted, punch location, long‐term and autosampler stability. Concentrations in DBS from a controlled cocaine administration study in healthy volunteers were compared to whole blood and plasma. Although concentrations correlated moderately to strongly (Spearman's ρ 0.603–0.958), agreement between paired samples was poor, with overestimation of DBS concentrations and wide confidence intervals in Bland–Altman analysis. A possible cause are differences in capillary and venous blood concentrations, with the underlying mechanism requiring further research before DBS analysis for cocaine and its metabolites can be considered equivalent to whole blood or plasma analysis.     

Limitation standard of toxic aconitines in Aconitum proprietary Chinese medicines using on-line extraction electrospray ionization mass spectrometry

Development of rapid analytical methods and establishment of toxic component limitation standards are of great importance in quality control of traditional Chinese medicine. Herein, an on-line extraction electrospray ionization mass spectrometry (oEESI-MS) coupled with a novel whole process integral quantification strategy was developed and applied to direct determination of nine key aconitine-type alkaloids in 20 Aconitum proprietary Chinese medicines (APCMs). Multi-type dosage forms (e.g., tablets, capsules, pills, granules, and liquid preparation) of APCM could be determined directly with excellent versatility. The strategy has the characteristics of high throughput, good tolerance of matrix interference, small amount of sample (∼0.5 mg) and reagent (∼240 μL) consumption, and short analysis time for single sample (<15 min). The results were proved to be credible by high performance liquid chromatography−mass spectrometry (LC–MS) and electrospray ionization mass spectrometry, respectively. Moreover, the limitation standard for the toxic aconitines in 20 APCMs was established based on the holistic weight toxicity (HWT) evaluation and the Chinese Pharmacopoeia severally, and turned out that HWT-based toxicity evaluation results were closer to the real clinical applications. Hence, a more accurate and reliable APCM toxicity limitation was established and expected to play an important guiding role in clinics. The current study extended the power of ambient MS as a method for the direct quantification of molecules in complex samples, which is commonly required in pharmaceutical analysis, food safety control, public security, and many other disciplines.     

Real-time toxicity prediction of Aconitum stewing system using extractive electrospray ionization mass spectrometry

Due to numerous obstacles such as complex matrices, real-time monitoring of complex reaction systems (e.g., medicinal herb stewing system) has always been a challenge though great values for safe and rational use of drugs. Herein, facilitated by the potential ability on the tolerance of complex matrices of extractive electrospray ionization mass spectrometry, a device was established to realize continuous sampling and real-time quantitative analysis of herb stewing system for the first time. A complete analytical strategy, including data acquisition, data mining, and data evaluation was proposed and implemented with overcoming the usual difficulties in real-time mass spectrometry quantification. The complex Fuzi (the lateral root of Aconitum)–meat stewing systems were real-timely monitored in 150 min by qualitative and quantitative analysis of the nine key alkaloids accurately. The results showed that the strategy worked perfectly and the toxicity of the systems were evaluated and predicated accordingly. Stewing with trotters effectively accelerated the detoxification of Fuzi soup and reduced the overall toxicity to 68%, which was recommended to be used practically for treating rheumatic arthritis and enhancing immunity. The established strategy was versatile, simple, and accurate, which would have a wide application prospect in real-time analysis and evaluation of various complex reaction systems.     

Chemical profiling of the synthetic cannabinoid MDMB‐CHMICA: Identification,assessment, and stability study of synthesis‐related impurities in seized and synthesized samples

In this work, the most discriminating synthesis‐related impurities found in samples from seizures and controlled synthesis of the synthetic cannabinoid MDMB‐CHMICA (methyl (S)‐2‐(1‐(cyclohexylmethyl)‐1H‐indole‐3‐carboxamido)‐3,3‐dimethylbutanoate) were characterized. Based on 61 available powder samples of MDMB‐CHMICA, 15 key‐impurities were assessed, isolated in larger quantities via flash chromatography and structurally elucidated and characterized via high resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Apart from verifying the relation of the impurities to the major component, the interpretation of their chemical structures with distinct structural elements provided first insights into the manufacturing process and the precursor compounds used. Following liquid chromatography mass spectrometry analysis of the 15 key‐impurities, the 61 seized samples of MDMB‐CHMICA were evaluated and classified via multivariate data analysis based on the corresponding relative peak areas. In a second part of this work, stability tests and multiple controlled syntheses of MDMB‐CHMICA were carried out to better understand variations in impurity signatures and to assess the significance of variations in the impurity patterns of seized samples. The last coupling step of the amino acid with 1‐(cyclohexylmethyl)‐1H‐indole‐3‐carboxylic acid was performed using the coupling agents oxalyl chloride, thionyl chloride, and HATU. Furthermore, the impact of reaction time and temperature on the impurity profile were investigated. Overall, eight new impurities were found in the controlled syntheses and two degradation products of MDMB‐CHIMCA were found in the course of the stability tests. Replicates of a synthesis conducted on the same day showed similar impurity signatures; on different days they showed discriminable signatures. The use of different coupling reagents or conditions gave clearly distinguishable impurity signatures.     

Cocaine adulteration with the anthelminthic tetramisole (levamisole/dexamisole): Long‐term monitoring of its intake by chiral LC–MS/MS analysis of cocaine‐positive hair samples

Recent studies indicate that not only the anthelminthic levamisole but also the racemate tetramisole (R‐/S‐phenyltetraimidazothiazole, PTHIT) was found as an adulterant for cocaine. We herein report on the investigation of the prevalence of PTHIT among cocaine‐positive hair samples and the discrimination of the presence of its stereoisomers levamisole and dexamisole. Cocaine‐positive hair samples were collected in a forensic context in 2015 and mainly 2017 (n = 724). Cocaine and PTHIT concentrations have been determined by achiral liquid chromatography–tandem mass spectrometry (LC–MS/MS). For distinction of levamisole/dexamisole chiral LC–MS/MS was performed. Cocaine hair concentrations ranged from 500 (cut‐off) to approximately 800 000 pg/mg. The study demonstrates a strong prevalence of PTHIT in cocaine users' hair (87%, n = 627). PTHIT hair concentrations ranged from below LLOQ 3.5 to approximately 61 000 pg/mg (median: 260 pg/mg). Surprisingly, enantiomeric ratios of levamisole/dexamisole ranged from 0.17 to 1.34 (median: 0.63). Therefore, PTHIT‐adulterated street cocaine samples (n = 24) seized between 2013 and 2016 were tested. Samples mainly contained racemic tetramisole (87.5%), only one sample contained levamisole only and two samples contained non‐racemic PTHIT. Our experiments suggest that the presence of tetramisole in biological samples may have hitherto been underestimated. Most probably higher dexamisole than levamisole concentrations in hair specimens arise from stereoselective metabolism and/or elimination. This is particularly important in light of the different pharmacological activities of the two enantiomers and potentially different adverse effects. Toxicological interpretations in intoxication cases with adulterated cocaine should not only consider levamisole but also tetramisole and terminology in scientific contributions should be used accordingly.     

MALDI MSI and LC‐MS/MS: Towards preclinical determination of the neurotoxic potential of fluoroquinolones

Fluoroquinolones are broad‐spectrum antibiotics with efficacy against a wide range of pathogenic microbes associated with respiratory and meningeal infections. The potential toxicity of this class of chemical agents is a source of major concern and is becoming a global issue. The aim of this study was to develop a method for the brain distribution and the pharmacokinetic profile of gatifloxacin in healthy Sprague‐Dawley rats, via Multicenter matrix‐assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) and quantitative liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). We developed a sensitive LC‐MS/MS method to quantify gatifloxacin in plasma, lung, and brain homogenates. A pharmacokinetic profile was observed where there is a double peak pattern; a sharp initial increase in the concentration soon after dosing followed by a steady decline until another increase in concentration after a longer period post dosing in all three biological samples was observed. The imaging results showed the drug gradually entering the brain via the blood brain barrier and into the cortical regions from 15 to 240 min post dose. As time elapses, the drug leaves the brain following the same path as it followed on its entry and finally concentrates at the cortex. Copyright © 2015 John Wiley & Sons, Ltd.     

Searching for novel biomarkers of centrally and peripehrally-acting neurotoxicants, using surface-enhanced laser desorption/ionisation-time-of-flight mass spectrometry (SELDI-TOF MS).

The neurotoxicity of chemicals to humans is difficult to monitor as there are no suitable methods of detecting early neuronal dysfunction. Here, a proof of principle study was designed to assess the potential of identifying protein biomarkers in accessible biofluids for this purpose. Groups of rats were treated with a range of doses of the model neurotoxicants, acrylamide (0, 2, 10, 50mg/kg) and methylmercury (0, 0.2, 1, 5mg/kg) for up to 3 weeks and samples of serum, urine, and cerebral spinal fluid analysed by surface-enhanced laser desorption/ionisation-time-of-flight mass spectrometry. There was no neuropathology up to the highest dose tested. Protein profiles were obtained from all samples and changes in the levels of many proteins were detected in both serum and urine, although not cerebral spinal fluid. In serum, the combination of three protein ion levels with m/z values of 4968, 9402 and 12,948 was able to correctly classify the treatment groups thus: 88% control, 100% acrylamide, 92% methylmercury. In urine, three protein ions with m/z values of 4944, 12,966 and 21,992 classified correctly the groups: 67% control, 94% acrylamide, 97% methylmercury. Similar classifications using other serum and urinary protein ions were also possible. This indicates the potential of serum and urine protein biomarkers for the assessment of sub-clinical neurotoxicity.     

Optimization and validation of simultaneous analyses of ecgonine,cocaine, and seven metabolites in human urine by gas chromatography–mass spectrometry using a one‐step solid‐phase extraction

The presence of ecgonine in urine has been proposed as an appropriate marker of cocaine use. Only a few methods have been published for their determination along with cocaine and the rest of its metabolites. Due to their high polarity and consequent solubility in water, these have low recoveries, which is why it is necessary to increase the sensitivity, by the formation of hydrochloric salts or multiderivatization of the analytes or by performing two solid‐phase extractions (SPEs), considerably increasing the time and cost of the analysis. This work describes a fast and fully validated procedure for the simultaneous detection and quantification of ecgonine, ecgonine‐methyl‐ester, benzoylecgonine, nor‐benzoylecgonine, m‐hydroxybenzoylecgonine, cocaethylene, cocaine, norcocaine, and norcocaethylene in human urine (500 μL) using one SPE and simple derivatization. Separation and quantification were achieved by gas chromatography–electron ionization–mass spectrometry (GC–EI–MS) in selected‐ion monitoring mode. Quantification was performed by the addition of deuterated analogs as internal standards. Calibration curves were linear in the adopted ranges, with determination coefficients higher than 0.99. The lower limits of quantification ranged from 2.5 to 10 ng/mL. The intra‐ and inter‐day precision, calculated in terms of relative standard deviation, were 1.2%–14.9% and 1.8%–17.9%, respectively. The accuracy, in terms of relative error, was within a ± 16.4% interval. Extraction efficiency ranged from 84% to 103%. Compared with existing methods, the procedure described herein is fast, since only one SPE is required, and cost‐effective. In addition, this method provides a high recovery for ecgonine, resulting in a better alternative to the previously published methods.     

Metabolic urinary profiling of alcohol hepatotoxicity and intervention effects of Yin Chen Hao Tang in rats using ultra-performance liquid chromatography/electrospray ionization quadruple time-of-flight mass spectrometry

This paper was designed to study metabonomic characters of the hepatotoxicity induced by alcohol and the intervention effects of Yin Chen Hao Tang (YCHT), a classic traditional Chinese medicine formula for treatment of jaundice and liver disorders in China. Urinary samples from control, alcohol- and YCHT-treated rats were analyzed by ultra-performance liquid chromatography/electrospray ionization quadruple time-of-flight mass spectrometry (UPLC/ESI-QTOF-MS) in positive ionization mode. The total ion chromatograms obtained from the control, alcohol- and YCHT-treated rats were easily distinguishable using a multivariate statistical analysis method such as the principal components analysis (PCA). The greatest difference in metabolic profiling was observed from alcohol-treated rats compared with the control and YCHT-treated rats. The positive ions m/z 664.3126 (9.00 min) was elevated in urine of alcohol-treated rats, whereas, ions m/z 155.3547 (10.96 min) and 708.2932 (9.01 min) were at a lower concentration compared with that in urine of control rats, however, these ions did not indicate a statistical difference between control rats and YCHT-treated rats. The ion m/z 664.3126 was found to correspond to ceramide (d18:1/25:0), providing further support for an involvement of the sphingomyelin signaling pathway in alcohol hepatotoxicity and the intervention effects of YCHT.