Evaporation-Free Extraction and Application in High-Throughput Bioanalysis by LC–MS-MS
Evaporation-free extraction (no drying down) is highly desirable because of its reduced cost and pollution, higher speed, and less possibility for contamination and conversion. Presented in this article are four types of evaporation-free extraction that are widely applicable. The first one is for the determination of didanosine over the range of 25.02–2502.00 ng/mL by injecting solid-phase extraction (SPE) eluate directly. The second is for the determination of betamethasone phosphate over the range of 2.51–250.60 ng/mL by injecting SPE eluate after pH adjustment. The third is for the determination of sumatriptan over the range of 0.99–99.40 ng/mL based upon SPE with high organic washing and low organic elution. The fourth is based upon automated dilution after protein precipitation for the determination of raloxifene-4'-glucuronide and raloxifene-6-glucuronide over the ranges of 2.02–202.40 ng/mL and 0.40–39.95 ng/mL, respectively.