Method Validation for the Analysis of Multiple Weight Loss Drugs in Dietary Supplement Materials by LC-MS/MS

A method validation is reported for the detection and quantification of multiple weight loss drugs in dietary supplement materials. The sample preparation was followed as described in LIB 4549 and the mass spectral measurements were accomplished using liquid chromatography tandem mass spectrometry with electrospray ionization. A method validation was performed at various fortification levels (250 and 1000 g/g) for all 11 drug compounds. The overall recoveries with standard deviation averaged 93.8 6.65% with the majority of individual recoveries in the range of 76% - 110%. The overall limits of quantification (LOQ) for analytes averaged at 10 ng/g. An overall indicator of linearity (R2) averaged at 0.9993 (0.0 250.0 ng/mL). The precision of five replicates of the 50 ng/mL level averaged at 98.4 0.41% with < 1%.