High Performance Liquid Chromatography-triple Quadrupole Research Articles

Assessment of the effects of Radix Bupleuri and vinegar-baked Radix Bupleuri on cytochrome 450 activity by a six-drug cocktail approach

AimTo assess the effects of Radix Bupleuri and vinegar-baked Radix Bupleuri on cytochrome 450 activity of rats. MethodsSix probe drugs (caffeine, midazolam, dextromethorphan, tolbutamide, omeprazole, chlorzoxazone) were simultaneously given to rats after different dosing of Radix Bupleuri or vinegar-baked Radix Bupleuri for seven days. The plasma concentrations of the six probes were measured by high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS) and their corresponding pharmacokinetic parameters were calculated. ResultsThe AUC and T1/2 of midazolam, dextromethorphan and chlorzoxazone decreased significantly (P < 0.05) in rats after different dosing of Radix Bupleuri or vinegar-baked Radix Bupleuri for seven days. Treatment of Radix Bupleuri decreased T1/2 and AUC of omeprazole, but treatment of vinegar-baked Radix Bupleuri with normal dose did not change the pharmacokinetics of omeprazole. The pharmacokinetics of tolbutamide in all vinegar-baked Radix Bupleuri-treated rats showed no statistically significant difference (P > 0.05) from that of controlled rats, however, treatment of Radix Bupleuri decreased tolbutamide T1/2. The pharmacokinetics of caffeine in all Radix Bupleuri or vinegar-baked Radix Bupleuri-treated rats showed no statistically significant difference (P > 0.05) from that of controlled rats. ConclusionThe Radix Bupleuri and vinegar-baked Radix Bupleuri have different effects on the CYP2C9 and CYP2C19. Radix Bupleuri and vinegar-baked Radix Bupleuri have strong induction effects on the CYP2E1, CYP2D6 and CYP3A4, however, have no impact on CYP1A2. The reason of different therapeutic effects of Radix Bupleuri and vinegar-baked Radix Bupleuri extract may be the different effects of Radix Bupleuri and vinegar-baked Radix Bupleuri on the CYP2C9 and CYP2C19.

Determination of priority pollutants in aqueous samples by dispersive liquid–liquid microextraction

A dispersive liquid–liquid microextraction (DLLME) method followed by high-performance liquid chromatography–triple quadrupole mass spectrometry has been developed for the simultaneous determination of linear alkylbenzene sulfonates (LAS C10, C11, C12, and C13), nonylphenol (NP), nonylphenol mono- and diethoxylates (NP1EO and NP2EO), and di-(2-ethylhexyl)phthalate (DEHP). The applicability of the method has been tested by the determination of the above mentioned organic pollutants in tap water and wastewater. Several parameters affecting DLLME, such as, the type and volume of the extraction and disperser solvents, sample pH, ionic strength and number of extractions, have been evaluated. Methanol (1.5mL) was selected among the six disperser solvent tested. Dichlorobenzene (50μL) was selected among the four extraction solvent tested. Enrichment factor achieved was 80. Linear ranges in samples were 0.01–3.42μg L−1 for LAS C10–13 and NP2EO, 0.09–5.17μgL−1 for NP1EO, 0.17–9.19μgL−1 for NP and 0.40–17.9μgL−1 for DEHP. Coefficients of correlation were higher than 0.997. Limits of quantitation in tap water and wastewater were in the ranges 0.009–0.019μgL−1 for LAS, 0.009–0.091μgL−1 for NP, NP1EO and NP2EO and 0.201–0.224μgL−1 for DEHP. Extraction recoveries were in the range from 57 to 80%, except for LAS C10 (30–36%). The method was successfully applied to the determination of these pollutants in tap water and effluent wastewater from Seville (South of Spain). The DLLME method developed is fast, easy to perform, requires low solvent volumes and allows the determination of the priority hazardous substances NP and DEHP (Directive 2008/105/EC).

Simultaneous determination of 24 constituents in Cortex Lycii using high-performance liquid chromatography–triple quadrupole mass spectrometry

A fast high-performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) tandem mass spectrometry method was developed to determine 24 components including 11 phenolic compounds, 9 phenolic amides, and 4 cyclic peptides in Cortex Lycii. The analytes were quantified by a triple quadrupole instrument in multiple reaction monitoring (MRM) mode. The fragmentation patterns of phenolic amides and cyclic peptides using ESI and collision-induced dissociation (CID) techniques are reported. This assay method was validated with respect to linearity (r2>0.9920), precision, repeatability, and accuracy (recovery rate between 93.0 and 105.9% with RSD<4.4%). The analytical results of 28 batches of Cortex Lycii indicated that cyclic peptides and phenolic amides were not only the abundant constituents, but also the characteristic components for Cortex Lycii to distinguish from the adulterants. Principle component analysis (PCA) was used to discriminate samples from different geographical regions of China, and cyclic peptides were considered to be the chemical markers responsible for the classification. The systematic and integrated assessment of Cortex Lycii provides sufficient evidence for the establishment of the quality standard.

Simultaneous determination of five Amadori compounds in tobacco by high performance liquid chromatography-mass spectrometry

A method of high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QqQ MS) in multiple reaction monitoring (MRM) mode for simultaneous determination of five Amadori compounds in tobacco has been developed. The separation was performed on an XBridge Amide column (250 mm x 4.6 mm, 3.5 microm) by gradient elution using methanol and water as mobile phases. The linearity of this method was good with the correlation coefficients (r) of 0.9895-0.9989. The limits of detection (S/N = 3) were from 3.51 microg/L to 14.86 microg/L, and the limits of quantitation (S/N = 10) were from 10.18 microg/L to 44.58 microg/L. The recoveries varied from 92.6% to 123.6% with the relative standard deviations (RSDs) less than 9.4%. The established method is rapid, accurate, robust and convenient, and it could be applied to the measurement of the five Amadori compounds in tobacco and cigarettes.

Simple, Rapid, and Simultaneous Assay of Multiple Carboxyl Containing Phytohormones in Wounded Tomatoes by UPLC-MS/MS Using Single SPE Purification and Isotope Dilution

An efficient simplified isotope dilution method was developed to determine four carboxyl containing phytohormones simultaneously in 200 mg of fresh tomato tissues using ultra high performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS) with negative electrospray ionization. The four phytohormones are indole-3-acetic acid (IAA), abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA). Only one purification step of Oasis MAX solid phase extraction (SPE) was employed to enrich target phytohormones after crude extraction. In addition, two endogenous isomers of JA, (-)-JA and (+)-7-iso-JA, were separated directly. The validated method has been applied to monitor changes of JA, SA, IAA, and ABA in both local and systemic leaves of wild-type and transgenic 35S::prosystemin (35S::PS) tomato lines. Meanwhile, the JA burst amplified by the overexpressed prosystemin in 35S::PS was verified. Furthermore, the spatial and temporal changes of JA, SA, ABA, and IAA were analyzed.

Hollow fiber-based liquid–liquid–liquid micro-extraction with osmosis: II. Application to quantification of endogenous gibberellins in rice plant

The phenomenon and benefits of osmosis in hollow fiber-based liquid–liquid–liquid micro-extraction (HF-LLLME) were theoretically discussed in part I of this study. In this work, HF-LLLME with osmosis was coupled with high performance liquid chromatography–triple quadrupole mass spectrometry (HPLC–triple quadrupole MS/MS) to analyze eight gibberellins (gibberellin A1, gibberellin A3, gibberellin A4, gibberellin A7, gibberellin A8, gibberellin A9, gibberellin A19 and gibberellin A20) in rice plant samples. According to the theory of HF-LLLME with osmosis, single factor experiments, orthogonal design experiments and mass transfer simulation of extraction process were carried out to select the optimal conditions. Cyclohexanol – n-octanol (1:3, v/v) was selected as organic membrane. Donor phase of 12mL was adjusted to pH 2 and 20% NaCl (w/v) was added. Acceptor phase with an initial volume of 20μL was the solution of 0.12molL−1 Na2CO3–NaHCO3 buffer (pH 9). Temperature was chosen to be 30°C and extraction time was selected to be 90min. Under optimized conditions, this method provided good linearity (r, 0.99552–0.99991) and low limits of detection (0.0016–0.061ngmL−1). Finally, this method was applied to the analysis of endogenous gibberellins from plant extract which was obtained with traditional solvent extraction of rice plant tissues, and the relative recoveries were from 62% to 166%.

Determination of the Nicotine Content in Solanaceae Vegetables by Solid-Phase Extraction Coupled with Ultra High-Performance Liquid Chromatography–Tandem Mass Spectrometry

A validated method based on solid-phase extraction and ultra high-performance liquid chromatography–triple quadrupole tandem mass spectrometry, with electrospray ionization operated in the positive ion mode and multiple reaction monitoring, was developed for the determination of nicotine in Solanaceae vegetables. Sample preparation involved liquid–solid extraction, centrifugation, filtration, and solid-phase extraction. Two kinds of solid-phase extraction adsorbents, based on different retention mechanisms, were investigated. Relatively higher recoveries were obtained with a hydrophilic–lipophilic-balanced cartridge. A deuterated internal standard was used for quantification. The limit of quantification (LOQ) of nicotine in different vegetables was found to be between 0.07 and 0.5 μg/kg. The nicotine levels in the vegetable samples were above the LOQs. The method described here is thus suitable for the analysis of large sample batches, because it provides accurate quantification, high sensitivity and rapid chromatographic separation with facile preparation. The solid-phase extraction cartridges and organic solvents used in this work are easy to obtain, enabling the application of this method in most analytical laboratories.

Simultaneous determination of a selected group of cytostatic drugs in water using high‐performance liquid chromatography–triple‐quadrupole mass spectrometry

In recent years, an increasing concern has risen about the presence of pharmaceuticals in the aquatic environment. Despite their toxicity, increasing consumption and release into the municipal sewage, only a few studies have been focused on cytostatic drugs, mainly due to the lack of methods for their simultaneous analysis. In this work, a method, based on solid-phase extraction prior to high-performance liquid chromatography-triple quadrupole mass spectrometry determination, was optimized and validated for the simultaneous determination of some (14) of the most widely used cytostatic drugs in river water, influent and effluent wastewater. Process efficiency was in the range between 41 and 99% in real samples, except for cytarabine (24%), docetaxel (17%) and methotrexate (30%), due to suppression effects; precision values were <11%, except for gemcitabine (up to 19%); and detection limits were in the range between 0.1 and 38 ng/L. Cytarabine, doxorubicin, etoposide, gemcitabine, iphosphamide and vinorelbine were found at concentration levels up to 14 ng/L in influent and effluent wastewater, showing an insignificant decrease during sewage treatment; cytarabine and gemcitabine were found in effluent wastewater and were also detected in river water associated with effluent discharges.

Quantitative analysis of hair samples for 1-benzylpiperazine (BZP) using high-performance liquid chromatography triple quadrupole mass spectrometry (LC-MS/MS) detection

Benzylpiperazine (BZP) is an amphetamine-type stimulant, which was legally available in New Zealand and widely used in "Party Pills" until reclassification as a Class C drug in April 2008. BZP was included as part of a multi-analyte method developed for hair screening using high-performance liquid chromatography triple quadrupole mass spectrometry (LC-MS/MS). A 20-mg sample of hair is extracted and partially purified using mixed-mode solid-phase extraction cartridges prior to analysis by LC-MS/MS. The method was developed as a broad screen for drugs of abuse (including amphetamines, opiates, and benzodiazepines), with only the BZP results being presented here. The assay was validated and found to be linear over the range of 0.085 to 8.65 ng/mg with correlation coefficient of r (2) ≥ 0.99. Blank hair samples spiked with BZP at 0.22 and 2.16 ng/mg gave intra- and inter-day precision coefficients of variation of ≤10% (n = 6 per day, 3 days) at both levels and calculated extraction efficiencies of 78% and 91%, respectively. The results from the samples submitted to the laboratory for BZP analysis showed 11% were positive (n = 126). The mean BZP level was 3.9 ng/mg (range, 0.4-33 ng/mg; the result was extrapolated when above the calibration). These data are the first available showing the levels expected from users of BZP.

Lead encephalopathy due to herbal medicine

Most herbal medicines are prescribed in combination based on the theory of TCM to obtain synergistic effects or diminish the possible adverse reactions. Compatibility refers to the combination of two or more herbs based on the clinical settings and the properties of herbs. Chrysophanol and physcion are the main effective compounds in Radix et Rhizoma Rhei and Dahuang Fuzi Decoction which is the combination of Radix et Rhizoma Rhei, Radix Aconiti Lateralis Praeparata and Radix et Rhizoma Asari. However, chrysophanol and physcion are difficult to detect in vivo because of their low concentration and interference from endogenous compounds. The aim of this study is to develop a rapid, specific and sensitive ultra high performance liquid chromatography–triple quadrupole tandem mass method to simultaneously quantify chrysophanol and physcion in rat plasma, in order to better understand the pharmacokinetics and compatibility mechanism of Dahuang Fuzi Decoction for the first time. Multiple reaction monitoring (MRM) mode was applied for the quantitation at [M−H]− m/z 253.0 → m/z 225.1 for chrysophanol, [M−H]− for m/z 283.1 → m/z 240.0 physcion and [M−H]− m/z 239.0 → m/z 211.0 for IS. The analytes were separated on an Agilent Eclipse plus C18 column (100 mm × 2.1 mm, 1.8 μm) column within a total running time of 6.5 min using a mixture of 3 mM ammonium acetate in water and methanol (95:5, v/v) with a time program flow gradient according to the “plus gradient chromatography” theory. The inclusion of the ammonium acetate in the UFLC mobile phase dramatically improved the detection limit of the tested compounds and decreased the interference by matrix effects, which have been referred to as “LC-electrolyte effects”. Finally, we demonstrated the application of a validated method in a comparative pharmacokinetic study of rats receiving an oral dose of Dahuang Fuzi Decoction or Radix et Rhei Rhizoma, the monarch drug in the prescription. Pharmacokinetic parameters showed significant difference between the two groups. The achieved comparative pharmacokinetic results were helpful to clarify the combination mechanism of Dahuang Fuzi Decoction.