title: Validated LC-MS/MS simultaneous assay of five sex steroid/neurosteroid-related sulfates in human serum.
abstract: Conventionally, the concentration of steroidal sulfates was estimated by indirect or immuno‑based assays before the use of liquid-chromatography tandem mass spectrometry (LC-MS/MS). In the present study, a validated LC-MS/MS method is described for the simultaneous quantification of dehydroepiandrosterone sulfate (DHEA-S), estrone sulfate (E1‑S), androsterone sulfate (ADT‑S), pregnenolone sulfate (Preg‑S) and allopregnanolone sulfate (Allopreg‑S). E1‑S binding to serum proteins was observed, especially for the high concentration quality control serum samples, leading to -10 to -15% bias using a polymer-based SPE. This protein binding can be efficiently eliminated using a Waters Oasis™ WAX following the same extraction procedure. Most likely, the E1‑S binding elimination on Oasis™ WAX can be attributed to its different sorbent structure, where the benzeno group of E1-S can interact with the benzene of the backbone of Oasis™ WAX. With this improvement, the method has been fully validated according to the FDA guidelines. The low quantification limits (LLOQs) are 40ng/mL, 40pg/mL, 5ng/mL, 1.5ng/mL and 0.25ng/mL for DHEA‑S, E1-S, ADT‑S, Preg‑S and Allopreg-S, respectively. A good linearity is obtained with R>0.99 for all compounds within the appropriate calibration range. Accuracies of all levels of QCs are within the range of 10% for DHEA-S, E1‑S, ADT‑S and Preg‑S while for Allopreg‑S, the accuracy is within the 15% range. The interday coefficient variance is 5.5-9.5% for the low limits of quantification of all five compounds while values of 1.3-9.9% are found for higher levels of QCs of all five compounds. Recovery of the five compounds in stripped serum is equivalent to that in unstripped serum. The average recovery difference is less than 5% between stripped and unstripped serum for each compound. All results of other test parameters such as matrix, hemolysis and lipemic effects as well as stabilities meet the acceptance criteria of EndoCeutics SOPs and FDA guidelines.
authors.affiliation: EndoCeutics Inc., Quebec City, Quebec G1V 4M7, Canada.
authors.forename: Alain Y
authors.initials: AY
authors.lastname: Dury
authors.affiliation: EndoCeutics Inc., Quebec City, Quebec G1V 4M7, Canada.
authors.forename: Yuyong
authors.initials: Y
authors.lastname: Ke
authors.affiliation: EndoCeutics Inc., Quebec City, Quebec G1V 4M7, Canada.
authors.forename: Renaud
authors.initials: R
authors.lastname: Gonthier
authors.affiliation: EndoCeutics Inc., Quebec City, Quebec G1V 4M7, Canada.
authors.forename: Maxim
authors.initials: M
authors.lastname: Isabelle
authors.affiliation: EndoCeutics Inc., Quebec City, Quebec G1V 4M7, Canada.
authors.forename: Jean-Nicolas
authors.initials: JN
authors.lastname: Simard
authors.affiliation: EndoCeutics Inc., Quebec City, Quebec G1V 4M7, Canada. Electronic address: fernand.labrie@endoceutics.com.
authors.forename: Fernand
authors.initials: F
authors.lastname: Labrie
mesh_terms: D000738:Androsterone / Q000031:analogs & derivatives* / Q000097:blood; D002853:Chromatography, Liquid / Q000379:methods; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood*; D004970:Estrone / Q000031:analogs & derivatives* / Q000097:blood; D006801:Humans; D057230:Limit of Detection; D011280:Pregnanolone / Q000097:blood*; D011284:Pregnenolone / Q000097:blood*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C018370:pregnenolone sulfate; D004970:Estrone; D019314:Dehydroepiandrosterone Sulfate; D011284:Pregnenolone; D011280:Pregnanolone; D000738:Androsterone; C017296:estrone sulfate; C026905:androsterone sulfate
keywords: Allopregnanolone sulfate; Androsterone sulfate; Dehydroepiandrosterone sulfate; Estrone sulfate; LC–MS/MS; Neurosteroid sulfates; Pregnenolone sulfate