利用UHPLC/Q-TOF MS技术进行知母中7个甾体皂苷的含量测定(英文)

本文利用UHPL C/Q-TOFMS技术建立了知母中7个主要甾体皂苷的含量测定方法,它们分别为知母皂苷N,知母皂苷E1,知母皂苷BⅡ,知母皂苷B,知母皂苷Ⅰ,知母皂苷A2和知母皂苷AⅢ。色谱柱为ACQUITY UPLC HSST3柱(2.1mm×100mm,1.8μm),流动相为乙腈–水(0.1%甲酸)梯度洗脱,分析时间为18分钟;LOQ和LOD分别为0.18–0.75ng/μL和0.05–0.22ng/μL;7个甾体皂苷分别在一定范围内呈现良好的线性关系,相关系数分别为0.9902–0.9979,且日内及日间精密度均低于5%,回收率为97.13%–101.98%。该方法快速、准确、重现性好,适用于知母药材及知母配方颗粒中7个甾体皂苷的含量测定。     

Microextraction by packed sorbent as sample preparation step for atorvastatin and its metabolites in biological samples--critical evaluation

Atorvastatin belongs to the group of lipid-lowering drugs known as statins. They significantly reduce the levels of total cholesterol, low-density cholesterol and plasma triglycerides therefore they are widely used in the treatment of hypercholesterolemia. Recently developed methods for the determination of atorvastatin and its metabolites in plasma used SPE (solid phase extraction) or LLE (liquid-liquid extraction) as the sample preparation step. However, both procedures are quite time-consuming and need relatively high volume of solvent/sample, which is impractical for the routine analyses of many biological samples. The aim of this work was to develop and validate more suitable sample preparation method for the determination of atorvastatin and its metabolites in biological samples using MEPS (microextraction by packed sorbent). The optimal conditions of MEPS extraction were using C8 sorbent and only 50 μl of the sample. The analytes were eluted by 100 μl of the mixture of acetonitrile:0.1 M ammonium acetate pH 4.5 (95:5, v:v). The analytical method was validated and demonstrated good linearity (r(2)>0.9990), recovery (89-115%) and intra-day precision (RSD<10%). Total time of the sample preparation was three times shorter (7 min) compared to SPE. The volume of sample was twenty times lower and the volume of solvents about ten times lower compared to SPE. Combination of fast MEPS method together with quick UHPLC-MS/MS was used for the determination of atorvastatin and its two metabolites in serum obtained from patients with familiar hypercholesterolemia.     

A fast ultra high pressure liquid chromatographic method for qualification and quantification of pharmaceutical combination preparations containing paracetamol, acetyl salicylic acid and/or antihistaminics

A fully validated UHPLC method for the identification and quantification of pharmaceutical preparations, containing paracetamol and/or acetyl salicylic acid, combined with anti-histaminics (phenylephrine, pheniramine maleate, diphenhydramine, promethazine) and/or other additives as quinine sulphate, caffeine or codein phosphate, was developed. The proposed method uses a Waters Acquity BEH C18 column (2 mm × 100 mm, 1.7 μm) with a gradient using an ammonium acetate buffer pH 4.0 as aqueous phase and methanol as organic modifier. The obtained method was fully validated based on its measurement uncertainty (accuracy profile) and robustness tests. Calibration lines for all components were linear within the studied ranges. The relative bias and the relative standard deviations for all components were respectively smaller than 1.5% and 2%, the β-expectation tolerance limits did not exceed the acceptance limits of 10% and the relative expanded uncertainties were smaller than 5% for all of the considered components.A UHPLC method was obtained for the identification and quantification of these kind of pharmaceutical preparations, which will significantly reduce analysis times and workload for the laboratories charged with the quality control of these preparations.     

Determination of a selection of synthetic cannabinoids and metabolites in urine by UHPSFC‐MS/MS and by UHPLC‐MS/MS

Two different analytical techniques, ultra‐high performance supercritical fluid chromatography‐tandem mass spectrometry (UHPSFC‐MS/MS) and reversed phase ultra‐high performance liquid chromatography‐tandem mass spectrometry (UHPLC‐MS/MS), were used for the determination of two synthetic cannabinoids and eleven metabolites in urine; AM‐2201 N‐4‐OH‐pentyl, AM‐2233, JWH‐018 N‐5‐OH‐pentyl, JWH‐018 N‐pentanoic acid, JWH‐073 N‐4‐OH‐butyl, JWH‐073 N‐butanoic acid, JWH‐122 N‐5‐OH‐pentyl, MAM‐2201, MAM‐2201 N‐4‐OH‐pentyl, RCS‐4 N‐5‐OH‐pentyl, UR‐144 degradant N‐pentanoic acid, UR‐144 N‐4‐OH‐pentyl, and UR‐144 N‐pentanoic acid. Sample preparation included a liquid‐liquid extraction after deconjugation with ß‐glucuronidase. The UHPSFC‐MS/MS method used an Acquity UPC^{2 TM} BEH column with a mobile phase consisting of CO₂ and 0.3% ammonia in methanol, while the UHPLC‐MS/MS method used an Acquity UPLC® BEH C₁₈ column with a mobile phase consisting of 5 mM ammonium formate (pH 10.2) and methanol. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions. Deuterated internal standards were used for six of the compounds. Limits of quantification (LOQs) were between 0.04 and 0.4 µg/L. Between‐day relative standard deviations at concentrations ≥ LOQ were ≤20%, with biases within ±19%. Recoveries ranged from 40 to 90%. Corrected matrix effects were within 100 ± 10%, except for MAM‐2201 with UHPSFC‐MS/MS, and for UR‐144 N‐pentanoic acid and MAM‐2201 N‐4‐OH‐pentyl with UHPLC‐MS/MS. Elution order obtained by UHPSFC‐MS/MS was almost opposite to that obtained by UHPLC‐MS/MS, making this instrument setup an interesting combination for screening and confirmation analyses in forensic cases. The UHPLC‐MS/MS method has, since August 2014, been successfully used for confirmation of synthetic cannabinoids in urine samples revealing a positive immunoassay screening result. Copyright © 2015 John Wiley & Sons, Ltd.     

In vivo metabolites and plasma exposure of TongMai Keli analyzed by UHPLC/DAD/qTOF-MS and LC/MS/MS

Ethnopharmacological relevance

TongMai Keli (TM) is a widely used traditional Chinese medicine preparation for the treatment of cardiovascular and cerebrovascular diseases. It is composed of Puerariae Lobatae Radix (roots of Pueraria lobata (Willd.) Ohwi), Salviae Miltiorrhizae Radix (roots of Salvia miltiorrhiza Bge.), and Chuanxiong Rhizoma (rhizomes of Ligusticum chuanxiong Hort.). The aim of this study is to identify the in vivo metabolites of TM, and to elucidate the pharmacokinetics of TM constituents and their metabolites.

Materials and methods

For metabolites identification, TM was orally administered to rats (n=3), and the metabolites in plasma were identified by UHPLC/DAD/qTOF-MS analysis and β-glucuronidase hydrolysis. For pharmacokinetic study, rats (n=10) were treated with TM at a clinical dose, and the plasma was analyzed by LC/MS/MS.

Results

A total of 25 metabolites from TM were identified in rats plasma. Glucuronide and sulfate conjugations were the major metabolic reactions, and produced 14 metabolites. The analytical method for pharmacokinetic study was fully validated with good linearity (r>0.99), wide dynamic ranges (6–6000 ng/mL), and low variations (<14.3%). The plasma concentration–time curves of puerarin and nine metabolites were profiled.

Conclusion

Isoflavones from Puerariae Lobatae Radix were the major metabolites in rat plasma after oral administration of TM. Puerarin and other isoflavone glycosides could reach their first C_max within 30 min, and were then rapidly eliminated, followed by their phase II metabolites.     

Distinguishing the cyanobacterial neurotoxin β-N-methylamino-l-alanine (BMAA) from other diamino acids

β-N-methylamino-l-alanine (BMAA) is produced by diverse taxa of cyanobacteria, and has been detected by many investigators who have searched for it in cyanobacterial blooms, cultures and collections. Although BMAA is distinguishable from proteinogenic amino acids and its isomer 2,4-DAB using standard chromatographic and mass spectroscopy techniques routinely used for the analysis of amino acids, we studied whether BMAA could be reliably distinguished from other diamino acids, particularly 2,6-diaminopimelic acid which has been isolated from the cell walls of many bacterial species. We used HPLC-FD, UHPLC-UV, UHPLC-MS, and triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) to differentiate BMAA from the diamino acids 2,6-diaminopimelic acid, N-2(amino)ethylglycine, lysine, ornithine, 2,4-diaminosuccinic acid, homocystine, cystine, tryptophan, as well as other amino acids including asparagine, glutamine, and methionine methylsulfonium.     

UHPLC/ESI‐Q‐TOF‐MS method for the measurement of dopamine in rodent striatal tissue: A comparative effects of intranasal administration of ropinirole solution over nanoemulsion

An ultra high performance liquid chromatography‐electrospray ionization‐tandem mass spectrometric method (UHPLC/ESI‐Q‐TOF‐MS) for the analysis of dopamine (DA) in Wistar rat brain homogenate has been developed and validated. The chromatographic separation was achieved on a Waters ACQUITY UPLC? BEH C18 (100.0 mm × 2.1 mm; 1.7 µm) column using isocratic mobile phase, consisting of acetonitrile and Formic acid (0.1% w/v) (10: 90; v/v), at a flow rate of 0.15 ml min^‐1. The transitions occurred at m/z 154.04 → 137.006 for DA, and m/z 184.204 → 166.08 for the internal standard. The recovery of the analytes from Wistar rat brain homogenate was optimized using liquid‐liquid extraction technique (LLE) in ethyl acetate. The total run time was 3.5 min and the elution of DA occurred at 1.44 ± 0.05 min. The linear dynamic range was established over the concentration range 75–750 ng mL^‐1 (r²; 0.9921 ± 0.0005) for DA. The intra‐assay and inter‐assay accuracy in terms of % CV was in the range 0.73–2.80. The lower limit of detection (LOD) and quantitation (LOQ) for DA was 0.278 and 0.844 ng mL^‐1, respectively. Analytes were stable under various conditions (in autosampler, during freeze–thaw, at room temperature, and under deep‐freeze conditions). The developed method was successfully applied for in vivo profiling in rodents. Copyright © 2012 John Wiley & Sons, Ltd.     

Screening method for stimulants in urine by UHPLC‐MS/MS: identification of isomeric compounds

A fast screening method for the detection of more than 60 stimulants in urine was developed. The method consisted of a dilution of the urine (1:5 v/v) and analysis by ultra high performance liquid chromatography coupled to tandem mass spectrometry, using a C18 column (1.7 µm particle size), a mobile phase containing deionized water and acetonitrile with formic acid, and gradient elution. The chromatographic run time was 5 min. The detection was performed in positive mode electrospray ionization, monitoring one or two specific ion transitions for each analyte. Appropriate repeatability was obtained, with relative standard deviation (RSD) values below 25% for most of the analytes. Regarding intermediate precision, estimated during routine work, higher RSDs were obtained, probably due to between‐day differences in the status of the mass spectrometer and in the chromatographic system. Matrix effect ranged from 60 to 255% with RSD lower than 35% for the majority of compounds. Despite the matrix effect observed, the signal/noise ratio of the analytes spiked at 50 ng/mL was greater than three in all tested samples, allowing a correct detection of all substances at the minimum required performance levels required by the World Anti‐Doping Agency and demonstrating the suitability of the method. The method was tested in administration study samples and satisfactorily in operation for more than one year with routine doping samples. The presence of isomeric stimulants with closely similar chromatographic and/or mass spectrometric properties did not allow the unequivocal identification of these compounds after the first analysis. Different possibilities for separation and identification of isomeric compounds are presented. Copyright © 2015 John Wiley & Sons, Ltd.     

The use of dried blood spots for quantification of 15 antipsychotics and 7 metabolites with ultra‐high performance liquid chromatography ‐ tandem mass spectrometry

Therapeutic drug monitoring of antipsychotics is important in optimizing individual therapy. In psychiatric populations, classical venous blood sampling is experienced as frightening. Interest in alternative techniques, like dried blood spots (DBS), has consequently increased. A fast and easy to perform DBS method for quantification of 16 antipsychotics (amisulpride, aripiprazole, asenapine, bromperidol, clozapine, haloperidol, iloperidone, levosulpiride, lurasidone, olanzapine, paliperidone, pipamperone, quetiapine, risperidone, sertindole and zuclopenthixol) and 8 metabolites was developed. DBS were prepared using 25 μL of whole blood and extraction of complete spots was performed using methanol: methyl‐t‐butyl‐ether (4:1). After evaporation, the extract was reconstituted in the mobile phase and 10 μL were injected on an ultra‐high performance liquid chromatography‐tandem mass spectrometry (UHPLC‐MS/MS). Separation using a C18 column and gradient elution with a flow rate of 0.5 mL/min resulted in a 6‐min run‐time. Ionization was performed in positive mode and a dynamic MRM method was applied. Median recovery was 66.4 % (range 28.7‐84.5%). Accuracy was within the acceptance criteria, except for pipamperone (LLOQ and low concentration) and lurasidone (low concentration). Imprecision was only aberrant for lurasidone at low and medium concentration. All compounds were stable during 1 month at room temperature, 4 °C and ?18 °C. Lurasidone was unstable when the extract was stored for 12 h on the autosampler. Absolute matrix effects (ME) (median 66.1%) were compensated by the use of deuterated IS (median 98.8%). The DBS method was successfully applied on 25‐μL capillary DBS from patients and proved to be a reliable alternative for quantification of all antipsychotics except for olanzapine and N‐desmethylolanzapine. Copyright © 2014 John Wiley & Sons, Ltd.