The determination of nonesterified fatty acids in blood serum using a stable cupric reagent.

A modification of the method for the determination of nonesterified fatty acids in blood serum using a stable cupric reagent stabilized with sodium citrate, has been developed. 33 g of NaCl are dissolved in 100 ml of the described reagent, and its pH should not be additionally adjusted. The reagent is stable for at least one year if kept in the refrigerator at 5 degrees C. The determination may be done in 0.1--0.2 ml of blood serum. The relationship between the absorbance and concentration of palmitic acid is still linear at a concentration of 2500 mumol/l. Error of the method is +/- 3%.