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

Objective: To develop a high resolution mass spectrometry (HRMS) method to quantify levonorgestrel (LNG) in serum. Study design: Levonorgestrel was extracted using solid phase extraction and measured using liquid chromatography (LC) HRMS. Results: Low 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 (R) 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). Conclusion: A sensitive, fast and simple LC-HRMS method was developed to detect trace levels of LNG. (C) 2019 Elsevier Inc. All rights reserved.