A validated procedure for detection and quantitation of salvinorin a in pericardial fluid, vitreous humor, whole blood and plasma using solid phase extraction and gas chromatography–mass spectrometry

The use of vitreous humor and pericardial fluid as alternative matrices to blood and plasma in the field of forensic toxicology is described to quantitate low levels of Salvinorin A using ethion as internal standard. The method was optimized and fully validated using international accepted guidelines. The developed methodology utilizes a solid phase extraction procedure coupled to gas chromatography mass spectrometry operated in the selected ion monitoring mode. The method was linear in the range of 5.0–100 ng/mL with determination coefficients higher than 0.99 in 100 μL of vitreous humor and in 250 μL of each matrix pericardial fluid, whole blood and plasma. The limits of detection and quantitation were experimentally determined as 5.0 ng/mL, intra-day precision, intermediate precision and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The sample cleanup step presented mean efficiencies between 80 and 106% in the different biological specimens analyzed. According to the low volumes of samples used, and the low limits achieved using a single quadrupole mass spectrometer, which is available in most laboratories, we can conclude that the validated methodology is sensitive and simple and is suitable for the application in forensic toxicology laboratories for the routine analysis of Salvinorin A in both conventional and unconventional biological samples.