Abstract: A method for preparation of a dried blood sample for multiplexing of analytes includes the steps of mixing an Internal Standard solution with a first diluent in a vessel, the Internal Standard solution including a plurality of different Internal Standards, adding the dried blood sample to the vessel, sonicating the vessel containing the Internal Standard solution, the first diluent and the dried blood sample, and removing the dried blood sample from the vessel. The Internal Standard solution can include a plurality of Internal Standards. The Internal Standard solution can include at least 15 Internal Standards. The dried blood sample can be generated using less than 50 ?L of blood. The dried blood sample can be generated using less than 10 ?L of blood. The first diluent can include methanol or a mixture of water and methanol.

Abstract: A method for qualitative and quantitative multiplexing of drug analytes from dried blood samples includes the steps of mixing an Internal Standard solution with a first diluent in a vessel, adding the dried blood sample to the vessel, sonicating the vessel containing the Internal Standard solution, the first diluent and the dried blood sample, removing the dried blood sample from the vessel so that a final sample can be attained, and analyzing at least a portion of the final sample using one of LC-MS and LC-MS/MS to simultaneously determine the presence or absence of a plurality of different analytes in the dried blood sample. The Internal Standard solution can include at least 8, 15, 25 or 50 Internal Standards. The dried blood sample is generated using less than 50 ?L, 20 ?L or 10 ?L of blood. The step of analyzing includes simultaneously determining the presence or absence of at least 15, 60, 90 or 130 different analytes.

Abstract: A method for qualitative and quantitative multiplexing of drug analytes from dried blood samples includes the steps of mixing an Internal Standard solution with a first diluent in a vessel, adding the dried blood sample to the vessel, sonicating the vessel containing the Internal Standard solution, the first diluent and the dried blood sample, removing the dried blood sample from the vessel so that a final sample can be attained, and analyzing at least a portion of the final sample using one of LC-MS and LC-MS/MS to simultaneously determine the presence or absence of a plurality of different analytes in the dried blood sample. The Internal Standard solution can include at least 8, 15, 25 or 50 Internal Standards. The dried blood sample is generated using less than 50 ?L, 20 ?L or 10 ?L of blood. The step of analyzing includes simultaneously determining the presence or absence of at least 15, 60, 90 or 130 different analytes.

Abstract: A method for qualitative and quantitative multiplexing of drug analytes from dried blood samples includes the steps of mixing an Internal Standard solution with a first diluent in a vessel, adding the dried blood sample to the vessel, sonicating the vessel containing the Internal Standard solution, the first diluent and the dried blood sample, removing the dried blood sample from the vessel so that a final sample can be attained, and analyzing at least a portion of the final sample using one of LC-MS and LC-MS/MS to simultaneously determine the presence or absence of a plurality of different analytes in the dried blood sample. The Internal Standard solution can include at least 8, 15, 25 or 50 Internal Standards. The dried blood sample is generated using less than 50 ?L, 20 ?L or 10 ?L of blood. The step of analyzing includes simultaneously determining the presence or absence of at least 15, 60, 90 or 130 different analytes.