title: Development and validation of a highly sensitive LC-MS/MS assay for the quantification of arginine vasopressin in human plasma and urine: Application in preterm neonates and child.
abstract: Arginine vasopressin is an endogenous neuropeptide secreted in response to situations such as hyperosmolality, hypotension and hypovolemia. The purpose of this study was to develop a reliable assay using small volumes of plasma and urine samples to quantify vasopressin levels in preterm infants. Weak cation solid-phase extraction was used to extract vasopressin from 200μl human plasma and urine samples. Separation was achieved on a Waters Acquity UPLC BEH C18 column by gradient elution at 0.55ml/min, with a mobile phase composed of methanol and 0.02% aqueous acetic acid solution. Analysis was performed under a hybrid triple quadrupole linear ion trap mass spectrometer, operated in multiple reaction monitoring mode using positive ionization. The linear response range was 1.0-40pg/ml for vasopressin, with the lower limit of quantification (LLOQ) of 1.0pg/ml in human plasma and urine. Recoveries at concentrations of 3, 10 and 32pg/ml were all greater than 70%, and matrix effects were within 15%. The method was validated with intra-day and inter-day precision of less than 8% for human plasma and urine. The intra-day and inter-day accuracy for human plasma were 91.9-100.6% and 92.3-104.8%, respectively. The intra-day and inter-day accuracy for human urine were 89.2-95.9% and 89.3-91.3%, respectively. The validated method was successfully applied to analyze two preterm neonate plasma samples and one child urine sample. In conclusion, the developed and validated method was sensitive and reliable, and was successfully used to quantify endogenous vasopressin levels in neonate plasma and child urine.
authors: Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77030, USA. Electronic address: dzhang11@uh.edu.
authors: Daping
authors: D
authors: Zhang
authors: Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address: drrios@texaschildrens.org.
authors: Danielle R
authors: DR
authors: Rios
authors: Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77030, USA. Electronic address: VHTam@central.uh.edu.
authors: Vincent H
authors: VH
authors: Tam
authors: Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77030, USA. Electronic address: phar33@central.uh.edu.
authors: Diana S-L
authors: DS
authors: Chow
mesh_terms: D001127:Arginine Vasopressin / Q000097:blood* / Q000652:urine*; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D057230:Limit of Detection; D008297:Male; D012015:Reference Standards; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D001127:Arginine Vasopressin
keywords: Arginine vasopressin; LC–MS/MS; Preterm neonates; SPE; Stability