Analytical Performance of LC-MS/MS Method for Simultaneous Determination of Five Steroids in Serum

The accurate measurement of steroid hormones is the fulcrum of modern endocrinology. Our aim was to develop a mass spectrometry coupled with a liquid chromatographic method for 17-hydroxyprogesterone, androstenedione, 11-desoxycortisol, 21-desoxycortisol and cortisol serum quantification simultaneously.

The samples were submitted to isotopic internal standards addition, protein precipitation and two dimensional liquid chromatography consists of trapping column and reverse-phase C18 analytical column.

For all compounds tested functional sensitivity was less than 0.5 ng/mL, precision was less than 15%, recovery ranged from 93% to 120%, linearity ranged from 89% to 111%, and accuracy was considered adequate.

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Biochemical Pathology in an Experimental Second-Hand Cigarette Smoke Exposure Model

White matter injury and degeneration are common features of developmental and aging-associated diseases, yet their pathobiological bases are poorly understood. However, recent advances in Matrix-Assisted Laser Desorption Ionization instruments and chemistry have provided critical tools for myelin-lipid analytical research.

This study characterizes Cigarette Smoke exposure effects on frontal lobe lipid ion profiles in adult male A/J mice that had been exposed to air for 8 weeks (A8), CS for 4 (CS4) or 8 weeks , or CS8 followed by 2 weeks recovery. MALDI data acquired by analysis of lipid extracts plated onto a ground steel target (high through-put) were compared with Imaging Mass Spectrometry.

MALDI-time-of-flight detected 120 lipid ions with m/z’s of 600 to 1300 (phospholipids and sulfatides) in samples plated onto the steel target or analyzed by IMS, but just 25 ions (18%) were detected by both methods.

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