Preservatives For Poisonings

• Most common  preservative  for  toxicological  specimen is  saturated  solution  of  sodium chloride  (NaCl).
• Toluene  is  the  best preservative  of urine  for  chemical  analysis and thymol  for  general purpose(Al
• Sodium  fluoride  is  added  to  CSF,  vitreous  humor  and urine  if  alcohol  estimation  is  required.
• Bones,nails and hair  are  preserved  in  poisoning  with  Arsenic , antimony,  radium,  thallium.
• Preservation of brain is not required in heavy metal poisoning. 

Table showing preservative  for different poisoning.

1	poisons  including,  carbolic  acid but  excluding other acids	Saturated  NaCl
2	Blood  for  grouping	Sodium  citrate in  water containing
3	Blood  for  Alcohol  poisoning	Potassium  oxalate  (anticoagulant)  and  sodium  fluoride(enzyme  inhibitor
4	Blood  for  fluoride  poisoning	Potassium  oxalate  and  sodium  nitrate  (in  place  of  sodium fluoride)
5	Blood  for  oxalic  acid  and ethylene  glycol  poisoning	Sodium citrate  (in  place  of potassium  oxalate)
6	Blood  for  carbon  monoxide (CO)  poisoning	Liquid  parafin
7	Urine	Saturated  salt/rectified  spirit/thymol/sodium  benzoate/ HCI
8	Tissue  for  histopathological  examination	10% formalin
9	Sample  for  uric  acid  (gouty  tophus)	Alcohol
10	Poisoning with acids, except  carbolic acid	Rectified spirit
11	Autopsy  specimen  for  virological  examination	50%  Glycerin

Don’t Forget to Solve all the previous Year Question asked on PRESERVATIVES FOR POISONINGS