We were recently given access to two drugs used to treat chronic lymphocytic leukaemia (CLL). We were curious to see whether these drugs were amenable to direct analysis without chromatography, utilising the Sciex API 3200 triple quadrupole mass spectrometer coupled to the Mass Spec Analytical (MSA) TEIS Ambient ionisation source. The TEIS (Thermal Extraction Ion Source) is an APCI source based on thermal desorption from two heated plates. Sample introduction can be effected without chromatography, either by means of paper swabs of solid material, toothpicks or in solution via syringe. Further, if a method could be developed, to investigate whether the compounds could be detected in an individuals sweat. Sweat has been advocated as a suitable matrix for the detection of traces of drugs of abuse and their metabolites.
Our Tech Note describes a qualitative method for the detection of two drugs that was rapidly developed (the whole programme of work described took less than half an hour, much faster than performing this work using liquid sample introduction). The detection of the two drugs, ibrutinib and allopurinol, in sweat, was effected by means of a paper swab of the skin surface. The analysis required no solvents or glassware, and took a matter of seconds. Note that the raw drug was detected rather than a metabolite. This represents a fast method of investigating whether or not a compound can be detected; an assessment can then be made as to whether or not to fully optimise and validate a new method for a wider range of applications.