Sensitive Liquid Chromatographic-mass Spectrometric Method Research Articles

A sensitive liquid chromatographic–mass spectrometric method for simultaneous quantification of six iridoid glycosides from Zhi-zi-chi Decoction in rat plasma and its application to a pharmacokinetic study

A sensitive liquid chromatographic–mass spectrometric (LC–MS) method was developed and validated for simultaneous determination of geniposide, geniposidic acid, scandoside methyl ester, gardenoside, deacetyl asperulosidic acid methyl ester and genipin-1-β-gentiobioside after oral administration of Zhi-zi-chi Decoction in rat plasma. The six iridoid glycosides were extracted from plasma samples by protein precipitation, and then separated on an Apollo C18 column (250mm×4.6mm, 5μm) through the application of a gradient elution. The analytes were monitored in positive electrospray ionization by selected ion monitoring mode (SIM). The lower limits of quantitation (LLOQ) of the six analytes were all lower than 6ng/mL. The accuracy (relative error, RE%) was between −7.0% and 9.9%, while the intra- and inter-day precisions (relative standard deviation, RSD%) were less than 6.3% and 9.8% for the six analytes, respectively. The developed method was successfully applied to a comparative pharmacokinetic study of the six iridoids in rat plasma after oral administration of Zhi-zi-chi Decoction and Gardenia jasminoides extract.

A sensitive liquid chromatographic–mass spectrometric method for simultaneous determination of dehydroevodiamine and limonin from Evodia rutaecarpa in rat plasma

A liquid chromatographic-mass spectrometric (LC-MS) method has been developed and validated for simultaneous determination of dehydroevodiamine and limonin from Evodia rutaecarpa in rat plasma. After addition of the internal standard, domperidone, plasma samples were extracted by liquid-liquid extraction with ethyl acetate and separated on an Apollo C(18) column (250 mm × 4.6 mm, 5 μm), with methanol-0.01% formic acid water (60:40, v/v) as mobile phase, within a runtime of 12.0 min. The analytes were detected without interference in the selected ion monitoring (SIM) mode with positive electrospray ionization. The linear range was 1.0-500 ng mL(-1) for dehydroevodiamine and 2.0-1,000 ng mL(-1) for limonin, with lower limits of quantitation of 1.0 and 2.0 ng mL(-1), respectively. Intra-day and inter-day precision were within 6.0% and 10.9%, respectively, for both analytes, and the accuracy (relative error, RE, %) was less than 4.8% and 6.5%, respectively. The validated method was successfully applied to a comparative pharmacokinetic study of dehydroevodiamine and limonin in rat plasma after oral administration of dehydroevodiamine, limonin, and an aqueous extract of Evodiae fructus. The results indicated there were obvious differences between the pharmacokinetic behavior after oral administration of an aqueous extract of Evodiae fructus compared with single substances.

Development and validation of a sensitive LC-MS method for the determination of Promethazine hydrochloride in human plasma and urine

We developed and validated a sensitive and low sample volume liquid chromatographic-mass spectrometric (LC-MS) method for determination of Promethazine hydrochloride in human plasma (0.5 ml) or urine (0.1 ml). The lower limit of quantification in human plasma and urine was 1.00 ng/ml. The inter- and intra-day precisions (CV %) in both plasma and urine were lower than 10%, the mean method accuracies and recoveries from spiked plasma samples at three concentrations were more than 97%. The developed method was successfully applied to determine Promethazine hydrochloride in human plasma and urine, and proved suitable to clinical pharmacokinetic study.

Determination of (E)-3,5,4′-Trimethoxystilbene in Rat Plasma by LC with ESI-MS

(E)-3,5,4′-trimethoxystilbene (BTM-0512) is a resveratrol analog with a variety of pharmacological action, including anti-cancer properties, anti-allergic activity, estrogenic activity, antiangiogenic activity, and vascular-targeting activity against microtubule-destabilization. There is, however, no validated analytical method for quantification of (E)-3,5,4′-trimethoxystilbene in biological matrices, so pharmacokinetic data and suitable methods for determination of the compound in plasma are currently lacking. A rapid and sensitive liquid chromatographic–mass spectrometric method for determination of (E)-3,5,4′-trimethoxystilbene in rat plasma, using carbamazepine as internal standard, has been developed and validated. Plasma samples were treated with acetonitrile to precipitate proteins. Samples were then analyzed by HPLC on a 250mm × 4.6 mm i.d., 5-μm particle, C18 column with methanol–water, 80:20 (v/v), containing 10 mm ammonium acetate and 0.2% formic acid (pH 3.0), as mobile phase, delivered at 0.85 mL min−1. A single-quadrupole mass spectrometer with an electrospray interface operated in selected-ion monitoring mode was used to detect [M + H]+ ions at m/z 271.3 for (E)-3,5,4′-trimethoxystilbene and m/z 237.5 for the internal standard. (E)-3,5,4′-trimethoxystilbene and the internal standard eluted as sharp, symmetrical peaks with retention times of 8.9 and 4 min, respectively. Calibration plots for (E)-3,5,4′-trimethoxystilbene in rat plasma at concentrations ranging from 0.01 to 5.0 μg mL−1 were highly linear. Intra-day and inter-day precision, as RSD, was <12.9%, and accuracy was in the range 94.8–104.7%. The limit of detection in plasma was 0.005 μg mL−1. The method was successfully used to determine the concentration of (E)-3,5,4′-trimethoxystilbene after oral administration of 86 mg kg−1 of the drug to Sprague–Dawley rats and can be used to investigate the pharmacokinetics of the compound.

Mass spectrometric determination of acromelic acid A from a new poisonous mushroom: Clitocybe amoenolens

As Clitocybe acromelalga, the mushroom Clitocybe amoenolens is responsible for erythermalgia. Acromelic acids isolated from C. acromelalga have been suspected to be to some extend the active principles. The objective was to develop a specific and sensitive liquid chromatographic–mass spectrometric method that would allow acromelic acid A identification and quantification in mushrooms. The method involved a single-step methanol–water extraction followed by a selective cleanup of the extract with solid-phase extraction cartridges (strong-anion exchange). The chromatographic separation was achieved on a porous graphitic carbon column with acetonitrile–water–formic acid as mobile phase. Detection was done with a mass analyzer equipped with a TurboIonSpray ® source, operated in the negative ionization mode. Acromelic acid A concentration was determined in dried mushroom at around 325 ng/mg in C. amoenolens and 283 ng/mg in C. acromelalga.