Search

A rapid and specific high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the quantification of hydroxysafflor yellow A (HSYA) in human urine with isorhamnetin-3-O-neohespeidoside as internal standard (IS). HSYA and IS were extracted from urine samples by simple solid-phase extraction and separated on an Agilent Zorbax SB C18 column (4.6 mm × 150 mm, 5 μm) with the mobile phase of 0.2 mM ammonium acetate: methanol (30/70, v/v) at a flow rate of 0.4 mL/min. Polar endogenous interferences eluted in 0.1-2.5 min were switched into waste channel by the Valve Valco, to reduce the possible matrix effect for MS detection in each run. The MS detection of analytes was performed on a tandem mass spectrometer equipped with an electrospray ionization source in negative mode using multiple-reaction monitoring. The MS/MS ion transitions monitored were m/z 611.3→491.2 for HSYA and m/z 623.2→299.2 for IS. The method was fully validated for selectivity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability, and then was applied to the urinary excretion study of injectable powder of pure HSYA in healthy Chinese volunteers for the first time. The results suggested that urine was the main excretion way of HSYA in healthy volunteers, further demonstrating the feasibility and necessity of our current method., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A method based on the on-line turbulent-flow chromatography and fast high-performance liquid chromatography/mass spectrometry (TFC-LC/MS) was developed for sensitive and high throughput pharmacokinetic study of traditional Chinese medicines (TCMs). In this method, an on-line extraction column (Waters Oasis HLB) and a fast HPLC column with sub-2 microm particle size (Agilent Zorbax StableBond-C(18), 4.6 mm x 50 mm, 1.8 microm) in a column-switching set-up were utilized. HLB is a reversed-phase extraction column with hydrophilic-lipophilic balanced copolymer (2.1 mm x 20 mm, 25 microm particle size), which will exhibit some turbulent-flow properties at a high-flow rate. The method combines the speed and robustness of turbulent-flow extraction and the sensitivity and separation efficiency of fast HPLC-MS to analyze multiple and trace constituents of TCMs in plasma matrix. This method was successfully applied for pharmacokinetic study of verticine, verticinone and isoverticine, the chemical markers of Fritillaria thunbergii, after oral administration of total steroidal alkaloids extract of F. thunbergii to rats. Each plasma sample was analyzed within 7 min. The method demonstrated good linearity (R>0.999) ranged from 0.505 to 96.0 ng/mL with satisfactory accuracy and precision, and the lower limit of quantifications of verticine, verticinone and isoverticine were estimated to be 0.120, 0.595 and 0.505 ng/mL, respectively. These results indicate that the proposed method is fast, sensitive, and feasible for pharmacokinetic study of TCMs., (2009 Elsevier B.V. All rights reserved.)

A rapid high-performance liquid chromatography-mass spectrometry (HPLC-MS) method was developed and validated for simultaneous quantification of 6-gingerol, 8-gingerol, 10-gingerol and 6-shogaol in rat plasma after oral administration of ginger oleoresin. Plasma samples extracted with a liquid-liquid extraction procedure were separated on an Agilent Zorbax StableBond-C(18) column (4.6 mm x 50 mm, 1.8 microm) and detected by MS with electrospray ionization interface in positive selective ion monitoring (SIM) mode. Calibration curves (1/x(2) weighted) offered satisfactory linearity (r(2)>0.995) in a wide linear range (0.0104-13.0 microg/mL for 6-gingerol, 0.00357-4.46 microg/mL for 8-gingerol, 0.00920-11.5 microg/mL for 10-gingerol and 0.00738-9.22 microg/mL for 6-shogaol). The lower limit of quantification (LLOQ) was in a range of 3.57-10.4 ng/mL. The analytes and internal standard can be baseline separated within 6 min. Inter- and intra-day assay variation was less than 15%. This developed method was successfully applied to pharmacokinetic studies of ginger oleoresin after oral administration to rats. Glucuronide of 6-gingerol was determined after beta-glucuronidase hydrolysis for more information, and the intestinal glucuronidation was further confirmed by comparison of plasma samples of hepatic portal vein and femoral vein.

A novel fast high-performance liquid chromatography (HPLC) method coupled with diode array detection (DAD) and time-of-flight mass spectrometry (TOF/MS) was developed for qualitative and quantitative analysis of Radix Astragali products. The potential of fast HPLC on 1.8-microm particles was compared with the performance of HPLC on conventional 5-microm particles columns. Significant advantages of fast HPLC include high-speed chromatographic separation, four times faster than HPLC with conventional columns, and great enhancement in sensitivity with limits of detection low to 0.001 ng. With dynamic adjustment of fragmentor voltage in TOF/MS, an efficient transmission of the ions was achieved to obtain the best sensitivity and abundant fragmentation. By accurate mass measurements within 5 ppm error for each molecular ion and subsequent fragment ions, a reliable identification and differentiation of six major saponins including two groups of isomers and twelve main isoflavonoids was described here for the first time. For quantitative analysis by fast HPLC-TOF/MS, linearity of response over two orders of magnitude was demonstrated (r(2)>0.99) for all analytes. Intra-day reproducibility was below 3% RSD and inter-day values were below 5% RSD. A good correlation (slope=1.1108, r(2)=0.9853) was observed for accuracy test. It is concluded that the fast and sensitive HPLC-DAD-TOF/MS is powerful in qualitative and quantitative analysis of complex herbal medicines in terms of time savings, sensitivity, selectivity, precision, accuracy as well as increasing sample throughout and lowering solvent consumption.

A sensitive and reliable high-performance liquid chromatography-mass spectrometry (HPLC-MS) was developed and validated for simultaneous quantification of five main bioactive components, i.e., calycosin-7-O-beta-D-glucoside, ononin, astragaloside IV, astragaloside I and ferulic acid in rat plasma after oral administration of Danggui Buxue Tang (DBT) extract. Plasma samples were extracted with solid-phase extraction (SPE) separated on an Inertsil ZORBAX C(18) column and detected by MS with electrospray ionization (ESI) interface in negative selective ion monitoring (SIM) mode. Calibration curves offered linear ranges of two orders of magnitude with r(2)>0.99. The method had the lower limit quantification of 0.55, 0.46, 1.07, 1.12 and 4.6 ng/mL for calycosin-7-O-beta-D-glucoside, ononin, astragaloside IV, astragaloside I and ferulic acid, respectively, with precision less than 10%. The RSD of intra- and inter-day variations ranged from 2.10% to 6.19% and 2.37% to 6.72%. This developed method was subsequently applied to pharmacokinetic studies of the five compounds in rats successfully.