<prompt> Which of the following is not used as a preservative in chemical analysisGlycerineFormalinSalt solutionRectified spirit  <response>: Formalin is not used as preservative for chemical analysis because extraction of poison becomes diffcult. Preservatives:- Saturated sodium chloride solution Rectified spirit 10 mgml of sodium or potassium fluoride for blood, urine, CSF Glycerol is used for virological study. Ref:- Essentials of Forensic medicine, Dr KS narayana Reddy 33th Edition; Pg num:- 124 