Paper Fingerprint Blog Titel 1920x540

New Pa­per Out

Ra­pid de­sorp­ti­on and ana­ly­sis for il­li­cit drugs and che­mi­cal pro­fil­ing of fin­ger­prints by SICRIT ion source

In: Drug Test­ing and Ana­ly­sis, 2023
Con­tri­bu­tors: Cia­ra Con­way, Mar­kus We­ber, Al­li­son Ferran­ti, Jan-Chris­­toph Wolf, Chris­toph Ha­isch


Fo­ren­sic ana­ly­sis can en­com­pass a wide va­rie­ty of ana­lytes from bio­lo­gi­cal samples in­clu­ding DNA, blood, se­rum, and fin­ger­prints to syn­the­tic samples like drugs and ex­plo­si­ves. In or­der to ana­ly­ze this va­rie­ty, the­re are va­rious sam­ple pre­pa­ra­ti­on tech­ni­ques, which can be time-con­sum­ing and re­qui­re mul­ti­ple ana­ly­ti­cal in­stru­ments. With re­cent ad­vance­ments in am­bi­ent io­niza­ti­on mass spec­tro­me­try (MS), plas­ma-ba­sed dielec­tric bar­ri­er di­schar­ge io­niza­ti­on (DBDI) sources have de­mons­tra­ted to co­ver a wide ran­ge of the­se ana­lytes. The flow-th­rough de­sign of this source also al­lows for easy con­nec­tion to a ther­mal de­sorp­ti­on type of sam­ple in­tro­duc­tion. We pre­sent an in-house built ther­mal de­sorp­ti­on de­vice whe­re the sam­ple is in­tro­du­ced via a glass slide, which gets hea­ted and trans­fer­red to the DBDI-MS with ni­tro­gen for iden­ti­fi­ca­ti­on and semi-quan­ti­fi­ca­ti­on. Using a glass slide as an in­ex­pen­si­ve sam­pling de­vice, de­tec­tion li­mits as low as 20 pg for fen­ta­nyl are de­mons­tra­ted. Ad­di­tio­nal­ly, a very pre­cise (>96% ac­cu­ra­cy) iden­ti­fi­ca­ti­on of per­sons ba­sed on the che­mi­cal pro­fi­le of their fin­ger­prints is pos­si­ble, es­tab­li­shing a di­rect ana­ly­ti­cal link of the drug trace to the in­di­vi­du­al in one me­a­su­re­ment. We com­pared the DAG, TAG, ste­rol, and (semi-)volatile re­gi­on of the aver­a­ged fin­ger­print spec­tra over mul­ti­ple days, show­ing the best mo­del ac­cu­ra­cy for iden­ti­fi­ca­ti­on ba­sed on the DAG re­gi­on. The com­bi­na­ti­on of ther­mal de­sorp­ti­on and DBDI-MS mi­ni­mi­zed sam­ple pre­pa­ra­ti­on, lea­ding to an ul­tra­sen­si­ti­ve and ra­pid ana­ly­sis of il­li­cit drug traces and the iden­ti­fi­ca­ti­on of un­der­ly­ing per­so­nas ba­sed on fin­ger­prints.