Monosegmented flow analysis of slow enzymatic reactions: Determination of triglycerides in serum

A monosegmented flow system (MCFA) is proposed to achieve slow enzymatic spectrophotometric determinations, here applied to the determination of triglycerides in blood serum. The sample (4.5 mu L), enzymatic reagent (150 mu L) and an air plug (100 mu L) are simultaneously inserted into a carrier stream buffered to pH 7.9 (Tris.HCl). In order to avoid the cumbersome step of air removal, a relocating detector was used. This system handles about 60 samples/h, yielding precise results (r.s.d. usually < 2.5%). Sensitivity is 56 mAU.L/mmol up to 6 mmol/L triglycerides. Accuracy was assessed by running 50 samples already analysed by a conventional procedure yielding the equation C-MCFA(mmol/L) = 1.00(+/- 0.04) C-Ref(mmol/L)- 0.03(+/- 0.08); r = 0.990.