API 5000 LCMSMS is the most sensitive triple quadrupole mass spectrometer for complex biological sample analysis and most used in complex biological samples analysis. API 5000 LCMSMS has a wide linear dynamic range, excellent quantitative analytical sensitivity, and especially suitable for quantitative analysis of low concentration components in complex matrices, when it analyze the quantitative of small molecule compounds ,it can promise the accuracy and reproducibility.. To reach the highest sensitivity requirement in DMPK and ADME research, API 5000 system is equipped with a new Qjet iontophoresis focusing device and Turbo V ion source, as well as a powerful new generation of analyst software, all these establish a new platform which is more suitable for each stage of drug development and high through-put analysis .