Gravesen J
J Clin Microbiol. 1977 Apr;5(4):390-2. doi: 10.1128/jcm.5.4.390-392.1977.
The acidimetric method for the determination of nicotinic acid (NA) using Lactobacillus plantarum ATCC 8014 (Lactobacillus arabinosus 17-5) has been simplified and thus made less time consuming, and the sensitivity has been increased fivefold by replacement of the titration by a pH determination. As the regression of the decrease in pH on the amount of NA was found linear within a range of 1 to 4 ng of NA per ml, the calculations were performed according to the slope-ratio principle. The NA concentration of plasma was determined with a coefficient of variation of 5 to 7%, which rose to about 10% at low NA concentrations. Assays of fasting plasma samples from 13 hyperlipidemic male patients showed a group mean NA concentration of 80 +/- 55 ng/ml (mean +/- 2 standard deviation), before treatment, and 705 +/- 544 ng/ml (mean +/- 2 standard deviation) during therapy with sustained release NA preparations, of which a single dose, ingested during steady-state conditions, doubled or tripled the plasma concentration within 1 to 3 h.
使用植物乳杆菌ATCC 8014（阿拉伯糖乳杆菌17 - 5）测定烟酸（NA）的酸量法已得到简化，因此耗时减少，并且通过用pH测定代替滴定，灵敏度提高了五倍。由于发现在每毫升1至4纳克NA的范围内，pH降低与NA量之间呈线性回归，因此根据斜率比原理进行计算。血浆中NA浓度的测定变异系数为5%至7%，在低NA浓度时升至约10%。对13名高脂血症男性患者的空腹血浆样本进行检测，结果显示治疗前群体平均NA浓度为80±55纳克/毫升（平均值±2标准差），在使用缓释NA制剂治疗期间为705±544纳克/毫升（平均值±2标准差），其中在稳态条件下摄入的单剂量在1至3小时内使血浆浓度增加了一倍或两倍。
