OBJECTIVE To establish a comprehensive analytical method based on SPE-UPLC-MS for the simultaneous determination of bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) in urine samples. METHODS Sixty urine samples collected from healthy subjects were analyzed for BPA, NP, and OP concentrations. The samples were de-conjugated by adding β-glucuronidase and sulfatase. After the enzymatic t...

Objective: To develop and validate simple, sensitive and selective ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS) method for quantification of rifampicin (RIF) in rat plasma and its application to pharmacokinetics study. Methods: Precipitation method was used for the extraction of plasma samples, an aliquot of 25 μl plasma samples was extracted using acetonitr...

The Fritillaria genus, including different kinds of medicinal and edible plants belonging to the Liliaceae family which have the function of treating and relieving a cough and eliminating phlegm, is widely planted in Xinjiang (China). There are few comprehensive studies reporting on the characterization of the chemical constituents of Fritillaria from Xinjiang, and to date, no work describing t...

Adenine phosphoribosyltransferase (APRT) deficiency is a hereditary disorder that leads to excessive urinary excretion of 2,8-dihydroxyadenine (DHA), causing nephrolithiasis and chronic kidney disease. Treatment with allopurinol or febuxostat reduces DHA production and attenuates the renal manifestations. Assessment of DHA crystalluria by urine microscopy is used for therapeutic monitoring, but...

BACKGROUND The dried root of Polygala tenuifolia, named Radix Polygalae, is a well-known traditional Chinese medicine. Triterpenoid saponins are some of the most important components of Radix Polygalae extracts and are widely studied because of their valuable pharmacological properties. However, the relationship between gene expression and triterpenoid saponin biosynthesis in P. tenuifolia is u...

In this study, a sensitive ultra-performance liquid chromatography-photodiode array coupled to quadruple time-of-flight mass (UPLC-PDA-Q/TOF-MS) method and a 1,1-diphenyl-2- picrylhydrazyl (DPPH)-based assay were used to determine the chemical constituents and screen the antioxidant activity profiles of the methanol extracts of different parts of cultivated Cistanche deserticola (C. deserticola...

INTRODUCTION The fast, precise, and accurate measurement of the new generation of oral anticoagulants such as dabigatran and rivaroxaban in patients' plasma my provide important information in different clinical circumstances such as in the case of suspicion of overdose, when patients switch from existing oral anticoagulant, in patients with hepatic or renal impairment, by concomitant use of in...

Michael E. Swartz, Ph.D. Principal Scientist, Waters Corporation, Milford, Massachusetts, e-mail [email protected]. igh performance liquid chromatography (HPLC) is a proven technique that has been used in laboratories worldwide over the past 30-plus years. One of the primary drivers for the growth of this technique has been the evolution of packing materials used to effect the separatio...