A sensitive method detecting trace levels of levonorgestrel using LC-HRMS

Abstract

ObjectiveTo develop a high resolution mass spectrometry (HRMS) method to quantify levonorgestrel (LNG) in serum. Study designLevonorgestrel was extracted using solid phase extraction and measured using liquid chromatography (LC) HRMS. ResultsLow limit of quantification (LLOQ) was 25 pg/mL and low limit of detection (LLOD) was 12.5 pg/mL. Precision and accuracy bias were <10%. LNG in serum samples from Mirena® users ranged between 37 to 219 pg/mL (n=12). In eight out of 22 patients with suspected intrauterine device (IUD) expulsion LNG was detected (26–1272 pg/mL). ConclusionA sensitive, fast and simple LC-HRMS method was developed to detect trace levels of LNG.