Researchers from ARUP Institute for Clinical and Experimental Pathology and the University of Utah have tested to establish if D&S provides acceptable data when compared to an existing, validated, solid phase extraction (SPE) procedure for opioids in urine samples. In their findings, D&S underestimated oxycodone concentrations in a sample as much as 45% compared to the existing method utilising SPE sample preparation.
They emphasize the importance of investigating matrix effects early on in the method validation process on a large number of specimens, in order to determine whether D&S sample preparation is adequate or whether more comprehensive sample preparation such as SPE is necessary.
Or, as an end user puts it: "OK so you’ve just bought a $300k mass spec. Now you're literally going to urinate in the front end of it. Doesn’t sound so good now does it?"