Evaluation of five multisteroid LC‒MS/MS methods used for routine clinical analysis: comparable performance was obtained for nine analytes.

Objectives: A mass spectrometry (LC‒MS/MS)-based interlaboratory comparison study was performed for nine steroid analytes with five participating laboratories. The sample set contained 40 pooled samples of human serum generated from preanalyzed leftovers. To obtain a well-balanced distribution across reference intervals of each steroid, the leftovers first underwent a targeted mixing step.

Non-Steroidal Drug Interferences in a Quantitative Multisteroid LC-MS/MS Assay.

Screening for possible interferences from steroidal compounds other than the target analytes (endogenous or exogenous) is well established in LC-MS/MS assay development for steroid quantification in a routine clinical setting. However, interferences from non-steroidal substances have, hitherto, not been explored. After screening more than 150 pharmaceuticals and their metabolites by analyzing commercial quality control samples from TDM analysis kits (Recipe, Chromsystems) with a multisteroid LC-MS/MS assay (protein precipitation followed by HybridSPE filtration, biphenyl column, methanol-water gradient with NH4F additive), we can report the finding of two newly discovered potential interferences from non-steroidal drugs.

Design and Validation of a Sensitive Multisteroid LC-MS/MS Assay for the Routine Clinical Use: One-Step Sample Preparation with Phospholipid Removal and Comparison to Immunoassays.

Steroid analysis in clinical laboratories is dominated by immunoassays (IAs) that have a high sample turnover but are inherently limited in trueness, precision, and sensitivity. Liquid chromatography coupled to mass spectrometry (LC-MS/MS) has proved to be a far more capable tool, delivering better sensitivity, specificity, and the possibility of parallel analysis of multiple steroids and metabolites, providing the endocrinologist with more reliable and comprehensive diagnostic information. An LC-MS/MS assay with gradient elution over less than eight minutes and a one-step sample preparation combining protein precipitation with phospholipid removal of off-line solid-phase extraction was developed and validated.

Chlorinated cobalt alkyne complexes derived from acetylsalicylic acid as new specific antitumor agents.

[(Prop-2-ynyl)-2-acetoxybenzoate]dicobalthexacarbonyl (Co-ASS), an organometallic derivative of the irreversible cyclooxygenase-1/2 (COX-1/2) inhibitor acetylsalicylic acid (ASS), demonstrated high growth-inhibitory potential against various tumor cell lines and inhibition of both COX isoenzymes. With the objective of increasing the selectivity for COX-2, we introduced a chlorine substituent in position 3, 4, 5, or 6 of the ASS moiety, respectively. Increased COX-2 selectivity is desirable as this isoenzyme is predominantly related to the development of cancer and abnormal tissue growth.