关键词: 游离脂肪酸, 羟苯磺酸钙, 酶法, 干扰

Abstract:

Objective To investigate the interference of calcium dobesilate in the determination of free fatty acid（FFA） using 6 acetyl-coenzyme A synthetase （ACS）-peroxidase coupled assays and its influence. Methods Calcium dobesilate solution with different concentrations was prepared by pure water,and was added into sera with 2 different FFA concentrations（550 and 1 200 μmol/L）. Serum FFA levels with final concentrations of calcium dobesilate additions（0,2,4,8,16,32 and 64 μg/mL） were determined using 6 ACS enzymatic assays（A,B,C,D,E and F,randomly）. Bias（%） was calculated in serum FFA with final concentration of calcium dobesilate addition（0 μg/mL）. Taking ±5% as an acceptable range of interference,the changes in serum calcium dobesilate levels observed before and after calcium dobesilate administration [baseline,0 h（valley concentration of drug in the stable state）,1 h,2 h,3 h,4 h and 6 h] in 40 participants were monitored by high performance liquid chromatography（HPLC）. Serum calcium dobesilate levels in 40 participants from those taking calcium dobesilate were determined. Results The level of serum calcium dobesilate（0 h） [median（interquartile range）] was 6.64（5.64-7.86）μg/mL. After taking 500 mg,the level of serum calcium dobesilate peaked at 2-3 h. The peak level of serum calcium dobesilate was 15.00（13.63-19.67）μg/mL,and then decreased gradually. The average level in 40 participants was 11.92（5.45-19.22）μg/mL. With the increase of serum calcium dobesilate level,the degree of interference in FFA determination also increased in in vitro experiment. For the low and high concentrations（550 and 1 200 μmol/L） of serum FFA,the biases in 6 ACS enzymatic assays were -0.40% - -65.01% and-0.20% - -52.33% in 8 μg/mL serum calcium dobesilate. The interference degrees of 4 ACS enzymatic assays can be accepted,except B and D. The biases in 6 ACS enzymatic assays were -1.68% - -28.28% and -1.81% - -16.48% in 16 μg/mL serum calcium dobesilate. Except kit A and kit C（high concentration of FFA）,the interference of other kits and kit C（low concentration of FFA） was beyond the acceptable range. The degree of interference was also related with basic serum FFA concentration. Under same calcium dobesilate concentration,the interference with lower concentration of serum FFA was more obvious. Conclusions In ACS enzymatic assays,calcium dobesilate produces a negative interference in the determination of FFA.

Key words: Free fatty acid, Calcium dobesilate, Enzymatic assays, Interference