Forrester R L, Wataji L J, Silverman D A, Pierre K J
Clin Chem. 1976 Feb;22(2):243-5.
We describe an enzymatic method, requiring only 10 mul of serum, for determining CO2 as bicarbonate or dissolved gas. Phosphoenolpyruvate carboxylase catalyzes the reaction of HCO3- with phosphoenolypyruvate to give oxalacetate. The resulting NADH, in the presence of malate dehydrogenase, is oxidized to NAD+, and the decrease in absorbance at 340 nm is directly proportional to the amount of CO2 present in the sample. Reaction is complete in 3 to 6 min under assay conditions, and is linearly related to CO2 concentrations between 8 and 65 mmol/liter. Analytical recovery is 95-110% (average, 101%). Two laboratories compared values obtained by continuous-flow analysis. The resulting correlation coefficients were 0.966 and 0.987, values for the t-test were t(paired) equals 0.473 and t(paired) equals 0.334, and average day-to-day precisions (three concentrations) were 3.9% and 4.2%.
我们描述了一种酶法，只需10微升血清即可测定作为碳酸氢盐或溶解气体的二氧化碳。磷酸烯醇丙酮酸羧化酶催化碳酸氢根与磷酸烯醇丙酮酸反应生成草酰乙酸。在苹果酸脱氢酶存在下，生成的NADH被氧化为NAD⁺，340nm处吸光度的降低与样品中二氧化碳的含量成正比。在测定条件下，反应在3至6分钟内完成，并且与8至65毫摩尔/升之间的二氧化碳浓度呈线性关系。分析回收率为95 - 110%（平均为101%）。两个实验室比较了连续流动分析获得的值。所得相关系数分别为0.966和0.987，t检验值分别为t（配对）= 0.473和t（配对）= 0.334，日常平均精密度（三种浓度）分别为3.9%和4.2%。
