High-Throughput LC-MS/MS Quantification of 17-Hydroxyprogesterone (17-OHP) in Human Blood Serum for Clinical Research Purposes

Instrument Type: LCMSMS

17-Hydroxyprogesterone (17-OHP) is a biosynthetic precursor to other steroids such as corticosteroids, androgens, and estrogens. It is converted to 11-deoxycortisol by 21-alpha-hydroxylase or to androstenedione by 17, 20 lyase. Researchers investigating how these enzymes function need to measure 17-OHP within an analytical range of 10 to 1,000 ng/dL (0.3 to 30 nmol/L) in blood serum. 17-OHP readily forms positive ions by atmospheric-pressure chemical ionization (APCI), which is less prone to matrix effects than electrospray ionization (ESI).

High-Throughput LC-MS/MS Quantification of Estrone (E1) and Estradiol (E2) in Human Blood Plasma/Serum for Clinical Research Purposes

Instrument Type: LCMSMS

Estrone (E1) and estradiol (17-beta-estradiol or E2) are two of several estrogens involved in the development and function of female anatomical and physiological characteristics and processes such as the menstrual cycle. Researchers seek to quantify E1 and E2 within an analytical range of 5 to 500 pg/mL (18.5 to 1,850 pmol/L) in blood plasma or serum. E1 and E2 form negative ions by deprotonation in both ESI and APCI MS sources. In order to robustly achieve the needed quantitation limits, most researchers use dansyl chloride to form positively charged derivatives of these and other estrogens.

High-Throughput LC-MS/MS Quantification of Pregnenolone in Human Blood Serum for Clinical Research Purposes

Instrument Type: LCMSMS

Pregnenolone is a biosynthetic precursor to other steroids such as corticosteroids, androgens, and estrogens. Researchers investigating conversion to progesterone or to 17-OH-pregnenolone need to quantify pregnenolone within an analytical range of 0.3 to 1.5 nmol/L in blood serum. Since pregnenolone does not ionize well, derivatization with hydroxyl amine was necessary to reliably achieve the desired detection. We pursued this strategy along with liquid-liquid extraction to develop a simple sample preparation that would provide robust and sensitive quantitation of pregnenolone using ESI.