i have attached a research article based on extraction techniques and procedures, i hope it would be helpful in your research.

For swabs we use(d) simple method. We put in the swab to small beaker (~50 ml), covered by ethanol (about 1 cm over swab). After that we put it in ultrasonic bath and sonified for 10 - 20 minutes. We empty ethanol from beaker  to Petri dish, rinse out more times beaker to perti dish and move it to heat plate placed in  extractor hood (with good ventilation) and completely dry. Prepare glue carbon disk, open one glue side and stick (disk kept in hand covered rubber glove or in tweezers) bottom of petri dish point to point. Place carbon disk to Al stub and analyse in SEM as normal GSR sample. There is relatively big possibility to find GSR particles. But in the opposite side all trash from swab, soluble in ethanol, is transferred to carbon tape. It is good practise coated surface of stub by carbon layer. Good luck. Tomas Kmjec

Thank you so much Sir, for your valuable Guidance