Development and validation of a liquid chromatography–tandem mass spectrometry method for the determination of nicotine and its metabolites in placenta and umbilical cord

Tobacco exposure during pregnancy is associated with obstetric and fetal complications. We developed and validated a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method to determine nicotine, cotinine, and hydroxycotinine (OH‐cotinine) in placenta (PL) and umbilical cord (UC). Specimens were homogenized in water, followed by solid‐phase extraction. Chromatographic separation was performed using an Atlantis® HILIC Silica column. Detection was accomplished in electrospray in positive mode. Method validation included: linearity (5 to 1000 ng/g), accuracy (86.9 to 105.2% of target concentration in PL, and 89.1 to 105.0% in UC), imprecision (6.8 to 11.8% in PL, and 7.6 to 12.2% in UC), limits of detection (2 ng/g for cotinine and OH‐cotinine, and 5 ng/g for nicotine) and quantification (5 ng/g), selectivity (no endogenous or exogenous interferences), matrix effect (?34.1 to ?84.5% in PL, %CV = 9.1–24.0%; ?18.9 to ?84.7% in UC, %CV = 10.2–23.9%), extraction efficiency (60.7 to 131.5% in PL, and 64.1 to 134.2% in UC), and stability 72 h in the autosampler (<11.5% loss in PL, and < 13% loss in UC). The method was applied to 14 PL and UC specimens from tobacco users during pregnancy. Cotinine (6.8–312.2 ng/g in PL; 6.7–342.3 ng/g in UC) was the predominant analyte, followed by OH‐cotinine (相似文献   

Development and validation of a simple and sensitive liquid chromatography–tandem mass spectrometry method for quantifying trimetazidine in human plasma

1. A simple and sensitive liquid chromatography–tandem mass spectrometry (LC‐MS‐MS) method for quantifying trimetazidine in human plasma was developed and validated. Sample preparation was based on deproteinating with acetonitrile. 2. Chromatography was performed on a C18 analytical column (5 μm; 150 × 2.1 mm i.d.) and the retention times for trimetazidine and cetirizine (used as the internal standard) were 1.8 and 3.0 min, respectively. The ionization was optimized using an electrospray ionization source and enhanced selectivity was achieved using tandem mass spectrometry. The calibration curve ranged from 0.1 to 200 ng/mL. The inter‐day precision, accuracy and the relative standard deviation (RSD) were all < 15%. The analyte was shown to be stable over the time‐scale of the entire procedure. 3. The robustness of the method was demonstrated by the good reproducibility of the results obtained during the analysis of clinical samples.     

Sensitive quantification of the somatostatin analog AP102 in plasma by ultra‐high pressure liquid chromatography–tandem mass spectrometry and application to a pharmacokinetic study in rats

AP102 is a di‐iodinated octapeptide somatostatin agonist (SSA) designed to treat acromegaly and neuroendocrine tumors. A sensitive and selective method was validated for the quantification of AP102 in plasma following the European Medicines Agency (EMA) and Food and Drug Administration (FDA) guidelines. Sample preparation was performed using solid‐phase extraction microplates. Chromatographic separation was achieved on an ultra‐high pressure liquid chromatography (UHPLC) C18 column in 6.0 minutes. The compounds were quantified using multiple reaction monitoring on a tandem quadrupole mass spectrometer with ¹³C,¹⁵N‐labeled AP102 as internal standard. Calibration ranged from 50 to 10000 pg/mL. The lower limit of quantification (LLOQ) was measured at 20 pg/mL, and robust analytical performances were obtained with trueness at 99.2%–100.0%, intra‐assay imprecision at 2.5%–4.4%, and inter‐assay imprecision at 8.9%–9.7%. The accuracy profiles (total error) built on the 3 concentrations levels showed accuracy within the 70%–130% range. AP102 is remarkably stable since no proteolytic fragments were detected on plasma samples analyzed by Orbitrap‐MS. Pharmacokinetic studies were conducted in rats, after single dose (1, 3, and 10 μg/kg, sc) and continuous subcutaneous administration (osmotic minipumps for 28 days, 3.0 or 10.0 μg/kg/h). AP102 showed a rapid absorption by the subcutaneous route (T_max: 15–30 minutes) and a fast elimination (t_1/2: 33–86 minutes). The PK profile of AP102 exhibited a mean clearance of 1.67 L/h and a mean distribution volume at steady state of 7.16 L/kg, about 10‐fold higher than those observed with other SSA or non‐ and mono‐iodinated AP102. LogD_7.4 determination confirmed the lipophilic properties of AP102 that might influence its distribution in tissues.     

Analysis for higenamine in urine by means of ultra‐high‐performance liquid chromatography–tandem mass spectrometry: Interpretation of results

Higenamine (Norcoclaurine) is a very popular substance in Chinese medicine and is present in many plants. The substance may be also found in supplements or nutrients, consumption of which may result in violation of anti‐doping rules. Higenamine is prohibited in sport at all times and included in Class S3 (β‐2‐agonists) of the World Anti‐Doping Agency (WADA) 2017 Prohibited List. The presence of higenamine in urine samples at concentrations greater than or equal to 10 ng/mL constitutes an adverse analytical finding (AAF). This work presents a new metabolite of higenamine in urine sample which was identified by means of ultra performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS). Samples were prepared according to 2 protocols – a Dilute and Shoot (DaS) approach and a method involving acid hydrolysis and double liquid‐liquid extraction (LLE). To meet the requirements typical for a confirmatory analysis, the screening procedure was further developed. In samples prepared by the DaS method, 2 peaks were observed; the earlier one was specific for higenamine and the later one unknown. MS scan analysis showed mass about 80 Da higher than that of higenamine. In turn, in samples prepared in accordance with the protocol involving hydrolysis, an increase in the area under peak for higenamine was observed, while the second peak was absent. It seems that the described strategy of detection of higenamine in urine avoids false negative results.     

Quantification of artemisinin in human plasma using liquid chromatography coupled to tandem mass spectrometry

A liquid chromatographic tandem mass spectroscopy method for the quantification of artemisinin in human heparinised plasma has been developed and validated. The method uses Oasis HLB™ μ-elution solid phase extraction 96-well plates to facilitate a high throughput of 192 samples a day. Artesunate (internal standard) in a plasma–water solution was added to plasma (50 μL) before solid phase extraction. Artemisinin and its internal standard artesunate were analysed by liquid chromatography and MS/MS detection on a Hypersil Gold C18 (100 mm × 2.1 mm, 5 μm) column using a mobile phase containing acetonitrile–ammonium acetate 10 mM pH 3.5 (50:50, v/v) at a flow rate of 0.5 mL/min. The method has been validated according to published FDA guidelines and showed excellent performance. The within-day, between-day and total precisions expressed as R.S.D., were lower than 8% at all tested quality control levels including the upper and lower limit of quantification. The limit of detection was 0.257 ng/mL for artemisinin and the calibration range was 1.03–762 ng/mL using 50 μL plasma. The method was free from matrix effects as demonstrated both graphically and quantitatively.     

Solid‐phase extraction–liquid chromatography–tandem mass spectrometry method for the qualitative analysis of 61 synthetic cannabinoid metabolites in urine

This article comprises the development and validation of a protocol for the qualitative analysis of 61 phase I synthetic cannabinoid metabolites in urine originating from 29 synthetic cannabinoids, combining solid‐phase extraction (SPE) utilizing a reversed phase silica‐based sorbent (phenyl) with liquid chromatography–tandem mass spectrometry (LC?MS/MS). Validation was performed according to the guidelines of the German Society of Toxicological and Forensic Chemistry. Sufficient chromatographic separation was achieved within a total runtime of 12.3 minutes. Validation included specificity and selectivity, limit of detection (LOD), recovery and matrix effects, as well as auto‐sampler stability of processed urine samples. LOD ranged between 0.025 ng/mL and 0.5 ng/mL in urine. Recovery ranged between 43% and 97%, with only two analytes exhibiting recoveries below 50%. However, for those two analytes, the LODs were 0.05 ng/mL in urine. In addition, matrix effects between 81% and 185% were determined, whereby matrix effects over 125% were observed for 10 non‐first‐generation synthetic cannabinoid metabolites. The developed method enables the rapid and sensitive detection of synthetic cannabinoid metabolites in urine, complementing the spectrum of existing analytical tools in forensic case work. Finally, application to 61 urine samples from both routine and autopsy case work yielded one urine sample that tested positive for ADB‐PINACA N‐pentanoic acid.     

Doping control analysis of four JWH‐250 metabolites in equine urine by liquid chromatography–tandem mass spectrometry

JWH‐250 is a synthetic cannabinoid. Its use is prohibited in equine sport according to the Association of Racing Commissioners International (ARCI) and the Fédération Équestre Internationale (FEI). A doping control method to confirm the presence of four JWH‐250 metabolites (JWH‐250 4‐OH‐pentyl, JWH‐250 5‐OH‐pentyl, JWH‐250 5‐OH‐indole, and JWH‐250 N‐pentanoic acid) in equine urine was developed and validated. Urine samples were treated with acetonitrile and evaporated to concentrate the analytes prior to the analysis by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The chromatographic separation was carried out using a Phenomenex Lux^® 3 μm AMP column (150 x 3.0 mm). A triple quadrupole mass spectrometer was used for detection of the analytes in positive mode electrospray ionization using multiple reaction monitoring (MRM). The limits of detection, quantification, and confirmation for these metabolites were 25, 50, and 50 pg/mL, respectively. The linear dynamic range of quantification was 50–10000 pg/mL. Enzymatic hydrolysis indicated that JWH‐250 4‐OH‐pentyl, JWH‐250 5‐OH‐pentyl, and JWH‐250 5‐OH indole are highly conjugated whereas JWH‐250 N‐pentanoic acid is not conjugated. Relative retention time and product ion intensity ratios were employed as the criteria to confirm the presence of these metabolites in equine urine. The method was successfully applied to post‐race urine samples collected from horses suspected of being exposed to JWH‐250. All four JWH‐250 metabolites were confirmed in these samples, demonstrating the method applicability for equine doping control analysis.     

The development and validation of a method for quantifying olanzapine in human plasma by liquid chromatography tandem mass spectrometry and its application in a pharmacokinetic study

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Separation of positional isomers of nine 2‐phenethylamine‐derived designer drugs by liquid chromatography–tandem mass spectrometry

The synthesis of positional isomers of designer drugs is a common way of bypassing legal restrictions. For forensic case work, and especially for the legal assessment of cases, there is a need for screening methods capable of the unequivocal identification of positional isomers. The presented liquid chromatography–electrospray ionization–tandem mass spectrometry (LC–ESI–MS/MS) method facilitates separation of positional isomers of 9 2‐phenethylamine‐derived designer drugs in different matrices including seized materials, hair, serum, and urine specimens. Chromatographic separation was achieved on a biphenyl phase using gradient elution with a total runtime of 26 minutes. The limit of detection was 25 pg/mg for hair samples and ranged from 0.1 ng/mL to 0.5 ng/mL for serum and from 0.2 ng/mL to 1.2 ng/mL for urine samples. The method proved to be selective and sensitive and showed good chromatographic resolution (R ≥ 1.2). The method was successfully applied to routine case samples.     

Ultra-performance liquid chromatography-tandem mass spectrometry for the determination of lacidipine in human plasma and its application in a pharmacokinetic study

A selective, rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–ESI-MS/MS) method was developed and validated for the quantification of lacidipine in human plasma. With nifedipine as an internal standard, sample pretreatment involved a simple liquid–liquid extraction with tert-butyl methyl ether of 1 ml plasma. The analysis was carried out on an Acquity™ UPLC BEH C₁₈ column (50 mm × 2.1 mm, 1.7 μm) with flow rate of 0.28 ml/min. The mobile phase was 30 mM ammonium acetate buffer–acetonitrile (18:82, v/v, pH 5.5). The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI). Linear calibration curves were obtained in the concentration range of 0.025–10.000 ng/ml, with a lower limit of quantification of 0.025 ng/ml. The intra- and inter-day precision (R.S.D.) values were below 15% and accuracy (RE) was −12.7% to 11.9% at all QC levels. The method was successfully applied to a clinical pharmacokinetic study of lacidipine in healthy volunteers following oral administration.     

A rapid and sensitive liquid chromatography–tandem mass spectrometric method for the determination of timosaponin B-II in blood plasma and a study of the pharmacokinetics of saponin in the rat

A rapid, sensitive and selective liquid chromatography–tandem mass spectrometric (LC–MS/MS) method was developed and validated for the determination of Timosaponin B-II (TB-II), a pharmacologically active constituent isolated from Anemarrhena asphodeloides. This method was used to examine the pharmacokinetics and bioavailability of TB-II in rats using ginsenoside Re as an internal standard. After simple protein precipitation of the plasma samples with acetonitrile, the analytes were separated on an ODS column (150 mm × 2.1 mm i.d., 5 μm) with the mobile phase of acetonitrile–water (35:65, v/v) containing 0.05% formic acid and detected by electrospray ionization mass spectrometry in the negative multiple reaction monitoring (MRM) mode with a chromatographic run time of 3.0 min. The calibration curves were linear over the range of 5–15,000 ng/ml and the lower limit of quantification (LLOQ) was 5 ng/ml in rat plasma. In this range, relative standard deviations (R.S.D.) were <7.4% for intra-day precision and <9.0% for inter-day precision. The accuracy was within the range of 97.7–107.3%. The method was successfully applied to assess the pharmacokinetics and oral bioavailability of TB-II after intravenous and oral administration in rats, with the oral bioavailability being only 1.1%.     

Simultaneous determination of a hydrophobic drug candidate and its metabolite in human plasma with salting-out assisted liquid/liquid extraction using a mass spectrometry friendly salt

In previously reported applications of salting-out assisted liquid/liquid extraction (SALLE) with acetonitrile, only inorganic salts were evaluated and implemented as the salting-out reagents. A potential concern of the method for the subsequent LC-MS analysis of biological samples was that a portion of the added salt (typically of high concentration) might be extracted and affect the chromatography separation and ionization of chromatography effluents in a mass spectrometer. Here we report, for the first time, the use of a mass spectrometry friendly organic salt, ammonium acetate, as a salting-out reagent in SALLE with acetonitrile for the simultaneous quantitation of an Abbott investigational new drug ABT-869 and its hydrophilic metabolite in human plasma. The performance of SALLE with ammonium acetate was compared with that of a previously reported method with a conventional liquid/liquid extraction technique using a set of pooled incurred samples. The % differences of the measured concentrations for 24 samples from these two methods were found to be within acceptance criteria, demonstrating SALLE with ammonium acetate as a reliable sample preparation technique. The SALLE method is simple, fast (25 min/plate), easy for automation, free of drying down step, and environmentally friendly. SALLE with mass spectrometry friendly salts has been applied to regulated sample analysis of both hydrophilic and hydrophobic compounds. It is envisioned that SALLE with acetonitrile and ammonium acetate be a universal method for high throughput automated sample preparation for bioanalytical chemistry.     

Liquid chromatography-tandem mass spectrometry assay for the quantitation of plagiochin E and its main metabolite plagiochin E glucuronides in rat plasma

Plagiochin E, a macrocyclic bisbibenzyl isolated from liverwort Marchantia polymorpha, was found to have antifungal activity. To evaluate the pharmacokinetics of plagiochin E in rats, a sensitive and specific liquid chromatography/tandem mass spectrometric (LC-MS/MS) method was developed and validated for the quantitation of plagiochin E and its total conjugated metabolites in rat plasma. For detection, a Sciex API 4000 LC-MS/MS with a TurboIonSpray ionization (ESI) inlet in the negative ion-multiple reaction monitoring (MRM) mode was used. The plasma samples were pretreated by a simple liquid-liquid extraction with ethyl acetate. The concentration of plagiochin E parent form was determined directly and the concentration of plagiochin E conjugated metabolites was assayed in the form of plagiochin E after treatment with beta-glucuronidase/sulfatase. The statistical evaluation for this method reveals excellent linearity, accuracy and precision for the range of concentrations 0.5-1000.0 ng/mL. The method had a lower limit of quantification (LLOQ) of 0.5 ng/mL for plagiochin E in 50 microL of plasma. The method was successfully applied to the characterization of the pharmacokinetic profile of plagiochin E in rats after an oral and an intravenous administration.     

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.     

Quantification of CKD-501, lobeglitazone, in rat plasma using a liquid-chromatography/tandem mass spectrometry method and its applications to pharmacokinetic studies

CKD-501 (i.e., lobeglitazone), a potent agonist for both PPARα/γ, is a new drug that has potential clinical applications in the management of type-2 diabetes. The objective of this study was to develop a rapid and sensitive method for the determination of CKD-501 in rat plasma and to assess the applicability of the assay to pharmacokinetic studies. Rat plasma samples were processed using a fast flow protein precipitation (FF-PPT) method and then introduced onto an LC–MS/MS system for quantification. The analyte and rosiglitazone, an internal standard, were analyzed by multiple reactions monitoring (MRM) at m/z transitions of 482.0 → 258.0 for CKD-501 and 358.0 → 135.0 for the internal standard. The lower limit of quantification (LLOQ) was determined at 50 ng/mL, with an acceptable linearity in the range from 50 to 10,000 ng/mL (R > 0.999). Validation parameters such as accuracy, precision, dilution, recovery, matrix effect and stability were found to be within the acceptance criteria of the assay validation guidelines, indicating that the assay is applicable to estimating the concentration in the range studied. The concentration of CKD-501 was readily quantifiable in plasma samples up to 24 h post-dose in rats that had received an oral dose of 1 mg/kg. These observations suggest, therefore, that the validated assay can be used in pharmacokinetic studies of CKD-501 in small animals such as the rat.     

Oxytocin analysis from human serum,urine, and saliva by orbitrap liquid chromatography–mass spectrometry

Oxytocin (OT) is a neurohormone that has gained interest recently due to its emerging role in cognition and social/emotional behaviors, including possibly depression and autism. OT is commonly measured using enzyme‐ or radio‐based immunoassays (RIA, ELISA), which lack specificity or are complicated to perform and involve hazardous radioactive material. We have developed a high resolution accurate‐mass (HRAM) liquid chromatography–mass spectrometry (LC–MS) method that separates interferences and selectively and accurately quantitates native OT from human serum, urine, and saliva after solid phase extraction. The doubly protonated OT ion m/z 562.25503 was selected for quantitation due its high signal intensity. With our method lower limit of detection (LLOD) of 5–25 pg/mL, we measured native OT in serum from pregnant women (16–24 pg/mL) and rats (350 pg/mL), and in serum, urine, and saliva from a healthy male after intranasal (IN) OT application of 100 IU and 20 IU and from a healthy post‐menopausal female after IN OT application of 100 IU. Peak levels were detected in serum, urine, and saliva 15–30 minutes after each dose then decreased to below detection limits 1–2 hours thereafter. We were unable to detect native OT in serum from non‐pregnant/non‐lactating/non‐medicated women due to levels known to occur below 5 pg/mL. The fast elimination of OT we found is in excellent agreement with the pharmacokinetics of OT in other studies. The effects on the central nervous system occurring after IN OT administration remains to be determined .     

Liquid chromatograph/tandem mass spectrometry assay for the simultaneous determination of chlorogenic acid and cinnamic acid in plasma and its application to a pharmacokinetic study

A rapid and high sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for simultaneous determination of chlorogenic acid and cinnamic acid in human plasma was developed. The analytes and internal standard (IS), tinidazole, were extracted from human plasma via liquid/liquid extraction with ether–ethyl acetate (1:1, v/v) and separated on an Agilent Zorbax SB C18 column within 5 min. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique, operating in multiple reaction monitoring (MRM) and negative ion mode. The precursor to product ion transitions monitored for chlorogenic acid, cinnamic acid and IS were m/z 352.9 → 191.1, 146.8 → 103.1, 245.6 → 126.0, respectively. The assay was validated with linear range of 1.00–800.00 ng/mL for chlorogenic acid and 0.50–400.00 ng/mL for cinnamic acid. The intra- and inter-day precisions (RSD%) were within 9.05% for each analyte. The absolution recoveries were greater than 74.62% for chlorogenic acid and 76.21% for cinnamic acid. Each analyte was proved to be stable during all sample storage, preparation and analytic procedures. The method was successfully applied to a pharmacokinetic study of Mailuoning injection in 10 healthy volunteers.     

Therapeutic drug monitoring of everolimus using the dried blood spot method in combination with liquid chromatography–mass spectrometry

An assay of everolimus based on finger prick sampling and consecutive application as a blood spot on sampling paper has been developed. We explored several methods [K. Hoogtanders, J. van der Heijden, M. Christiaans, P. Edelbroek, J. van Hooff, L. Stolk, J. Pharm. Biomed. Anal. 44 (2006) 658–664; A. Allanson, M. Cotton, J. Tettey, et al., J. Pharm. Biomed. Anal. 44 (2007) 963–969] and developed a new method, namely the impregnation of sampling paper with a solution of plasma–protein, formic acid and ammonium acetate, in combination with the extraction of the blood spot by filter filtration. This kind of sample preparation provides new possibilities for blood spot sampling especially if analytes are adsorbed to the paper.The dried blood spot was analysed using the HPLC–electrospray-tandem mass spectrometry method, with 32-desmethoxyrapamycin as the internal standard. The working range of our study was 2–30 μg/l. Within this range, intra-and inter-assay variability for precision and accuracy was <15%. Everolimus blood spot samples proved stable for 3 days at 60 °C and for 32 days at 4 °C. Everolimus concentrations of one stable out-patient were compared after both blood spot sampling and conventional venous sampling on various occasions. Results indicate that this new method is promising for therapeutic drug monitoring in stable renal transplant patients.     

PMEA-Na在beagle犬血浆中的液相色谱/质谱/质谱联用法测定及其药代动力学

目的建立LC/MS/MS法测定犬血浆中PMEA-Na浓度,进行其药代动力学研究.方法血浆样品经甲醇沉淀蛋白后,采用多反应监测法测定其血药浓度.色谱柱为Xterra MS柱,流动相为甲醇水甲酸(25750.5),流速为 0.25 ml·min-1.Beagle犬分3个剂量组经静脉给药,给药剂量分别为 1.0、3.0 和 6.0 mg·kg-1.药代动力学参数通过DAS软件计算获得.结果PMEA-Na线性范围0.02～20 mg·L-1 (r=0.999);最低检测浓度为 20 μg·L-1,方法回收率为 97.1%～107.3%,日内日间变异分别小于 6.5%、10.8%.beagle 犬在 1.0, 3.0 与 6.0 mg·kg-1剂量下单次iv PMEA-Na后,测得其AUC分别为 2.3±0.5, 8.2±1.3 and 18.5±1.3 mg·L-1·h; t1/2 为 3.9±1.8, 8.4±1.5 and 8.9±0.6 h; CL为 0.44±0.09, 0.35±0.05 and 0.31±0.03 ml·h-1·kg-1.结论本方法专属性强,准确性好,可用于PMEA-Na血药浓度测定和药代动力学研究.     

Simultaneous detection and quantitation of organic impurities in methamphetamine by ultra‐high‐performance liquid chromatography–tandem mass spectrometry,a complementary technique for methamphetamine profiling

The analysis of organic impurities plays an important role in the impurity profiling of methamphetamine, which in turn provides valuable information about methamphetamine manufacturing, in particular its synthetic route, chemicals, and precursors used. Ultra‐high‐performance liquid chromatography – tandem mass spectrometry (UHPLC – MS/MS) is ideally suited for this purpose due to its excellent sensitivity, selectivity, and wide linear range in multiple reaction monitoring (MRM) mode. In this study, a dilute‐and‐shoot UHPLC – MS/MS method was developed for the simultaneous identification and quantitation of 23 organic manufacturing impurities in illicit methamphetamine. The developed method was validated in terms of stability, limit of detection (LOD), lower limit of quantification (LLOQ), accuracy, and precision. More than 100 illicitly prepared methamphetamine samples were analyzed. Due to its ability to detect ephedrine/pseudoephedrine and its high sensitivity for critical target markers (eg, chloro‐pseudoephedrine, N‐cyclohexylamphetamine, and compounds B and P), more impurities and precursor/pre‐precursors were identified and quantified versus the current procedure by gas chromatography – mass spectrometry (GC – MS). Consequently, more samples could be classified by their synthetic routes. However, the UHPLC – MS/MS method has difficulty in detecting neutral and untargeted emerging manufacturing impurities and can therefore only serve as a complement to the current method. Despite this deficiency, the quantitative information acquired by the presented UHPLC – MS/MS methodology increased the sample discrimination power, thereby enhancing the capacity of methamphetamine profiling program (MPP) to conduct sample‐sample comparisons.