A rapid and reliable method for the quantitation of hydroxychloroquine in serum using turbulent flow liquid chromatography-tandem mass spectrometry

• Published in: Clinica chimica acta 2013-06, Vol.421, p.79-84
• Main Authors: Füzéry, Anna K., Breaud, Autumn R., Emezienna, Nkechinyere, Schools, Sabitha, Clarke, William A.
• Format: Article
• Language: English
• Subjects: Chemical Precipitation; Chromatography, Liquid - methods; Humans; Hydroxychloroquine; Hydroxychloroquine - blood; Hydroxychloroquine - therapeutic use; Lupus Erythematosus, Systemic - blood; Lupus Erythematosus, Systemic - drug therapy; Mass spectrometry; Perchlorates; Sensitivity and Specificity; Serum; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Time Factors; Turbulent flow liquid chromatography
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/j.cca.2013.02.018

Hydroxychloroquine is routinely used in managing systemic lupus erythematosus and rheumatoid arthritis. Whole blood levels are currently measured in the laboratory but at least one study suggests that serum levels may be equally useful. Moreover, serum samples are the preferred matrix type in the clinical laboratory as a result of their reduced complexity compared to whole blood. These observations suggest that the clinical utility of serum hydroxychloroquine levels needs to be reevaluated using larger studies and more robust assays. We report a turbulent flow LC-MS/MS method we developed for this purpose. After protein precipitation from serum with 0.33mol/l perchloric acid, hydroxychloroquine and its deuterated analog were injected onto a Cyclone turbulent flow column for sample cleanup. Analytical separation was accomplished on a HypersilGold C8 column with a gradient of water and methanol, each containing 0.1% formic acid and 10mmol/l ammonium formate. Analytes were ionized and detected by electrospray ionization mass spectrometry with multiple reaction monitoring. Our method was linear from 15.7 to 2000ng/ml. Total imprecision at multiple levels was