Determination of serum vitamins 25-OH-D2 and 25-OH-D3 with liquid chromatography-tandem mass spectrometry using atmospheric pressure chemical ionization or electrospray source and core-shell or sub-2 μm particle columns: a comparative study.

Objective: Develop a simple LC-MS-MS method for determination of 25-hydroxymetabolites of vitamin D2 and D3 in serum.

Design And Methods: 0.1 mL serum was mixed with 0.

Simultaneous LC-MS-MS determination of cyclosporine A, tacrolimus, and sirolimus in whole blood as well as mycophenolic acid in plasma using common pretreatment procedure.

The purpose of the study was to develop rapid and simple procedure for simultaneous determination of cyclosporine A (CsA), tacrolimus (TCR), and sirolimus (SIR) in whole blood and mycophenolic acid (MPA) in plasma. Ascomycin (ASCO), cyclosporine D (CsD), and desmethoxysirolimus (DMSIR) were used as internal standards (IS) for TCR, CsA and MPA, and SIR, respectively. In the method development, six-level blood calibrators were used for CsA (range 47-1725 ng/ml), TCR (range 2.

Application of LC-ESI-MS-MS for detection of synthetic adulterants in herbal remedies.

Adulteration of allegedly "natural herbal medicines" with undeclared synthetic drugs is a common and dangerous phenomenon of alternative medicine. The purpose of the study was to develop a procedure for detection of most common synthetic adulterants in herbal remedies, using high-pressure liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS-MS). Eighty drugs belonging to various pharmacological classes were included in the study.

Rapid determination of chloramphenicol and its glucuronide in food products by liquid chromatography-electrospray negative ionization tandem mass spectrometry.

Chloramphenicol (CAP) is subjected to monitoring in food products, with a minimum required performance level set at 0.3 ng/g. CAP was isolated from chicken meat and seafood by very simple solvent extraction procedure.

Rapid determination of benzo(a)pyrene in olive oil samples with solid-phase extraction and low-pressure, wide-bore gas chromatography-mass spectrometry and fast liquid chromatography with fluorescence detection.

Benzo(a)pyrene (B(a)P) was extracted from olive oil using solid-phase extraction on columns filled with Florisil and Nucleoprep C18. The extracts were analyzed with GC-MS, using standard capillary column and low-pressure wide-bore column (LP-GC-MS), as well as with HPLC on standard column and short donor-acceptor complex chromatography (DACC) column. Quantitation was done with isotope dilution method (GC-MS and LP-GC-MS) or with internal standard benzo(k)fluoranthene (HPLC).

How natural are 'natural herbal remedies'? A Saudi perspective.

Objective: There is a rapidly growing trend in the consumption of herbal remedies in industrialised and developing countries. Users of herbal remedies are at risk of toxicity and adverse interactions of herbal preparations due to their frequent contamination with metals and adulteration with synthetic drugs. The purpose of this study was to assess the quality of herbal remedies present on the market in Saudi Arabia in recent years.