Abstract
A rapid method based on high-performance liquid chromatography/electrospray–mass spectrometry (HPLC/ESI-MS) for the quantitative determination of alendronate in human urine has been developed and validated. Improved chromatographic separation and increased sensitivity of the detection was achieved by derivatisation. Higher efficiency of derivatisation as well as, more discriminatory recovery of the drug’s derivatives was obtained by the use of ‘on-cartridge’ reaction with diazomethane. Important parameters such as sensitivity, linearity, matrix effect, reproducibility, stability, carry-over and recovery were investigated during the validation. The lower limit of detection was found to be 0.250 ng/mL. The intra- and inter-run precision, calculated from quality control (QC) samples was less than 5.0 %. The accuracy as determined from QC samples was in the range of 93.4–107.0% for the analyte. The mean recoveries for the low, medium and high quality control samples were 97.6 %, 97.0 % and 98.7 % respectively. Various conditions arising from potential interference peaks as a result of chromatographic separation of desired analytes were optimized. The developed method can provide a very useful technique for the analysis of drugs in human subjects.