Huang Y S, Kubo H, Kinoshita T
Shenyang College of Pharmacy.
Yao Xue Xue Bao. 1991;26(12):928-32.
A method for the fluorometric determination of pyridine and its derivatives has been developed by flow injection analysis using hydrogen peroxide at high temperature. The reaction system consists of two pumps to deliver reagent and carrier stream, sample injector, reaction coil (0.5 mm ID x 15 m, 150 degrees C), cooling coil (0.5 mm ID x 3 m, 30 degrees C), and cooling coil (0.5 mm ID x 20 cm, 0 degrees C). The wavelengths of the fluorometric spectrophotometer were set at Ex 305-350 nm and Em 380-410 nm, the flow rate of each solution was 1.0 ml/min. The carrier stream was deionized water. The reaction solution containing 10 mmol/L hydrogen peroxide in 0.2 mol/L phosphate buffer (pH 6.0) gave the maximum fluorescence intensity for pyridine and its derivatives. Linear calibration curves were obtained from 5 ng up to 100 ng of pyridine and its derivatives. The coefficient of variations for 2.5 ng (n = 10) and 25 ng (n = 10) of isonicotinic acid, isoniazide and acetylisoniazide were 1.8% and 1.1%, 1.6% and 1.2%, 2.1% and 1.4%, respectively. The detection limit (S/N = 3) was 250 pg for isonicotinic acid, 500 pg for isoniazide, acetylisoniazide, nicotinamide, isonicotinamide, nicotinic acid, and 2.5 ng for pyridine, nicotine, 2--picoline, 2--picolinamide and picolinic acid. The carrier stream containing organic solvent (methanol, ethanol or acetonitrile) decreased the fluorescence intensity, but in the case of acetonitrile there was less decrease than methanol or ethanol. This method allowed the analysis of 30 samples/h.
已开发出一种通过高温下使用过氧化氢的流动注射分析法对吡啶及其衍生物进行荧光测定的方法。反应系统由两个用于输送试剂和载流的泵、进样器、反应盘管（内径0.5毫米×15米，150℃）、冷却盘管（内径0.5毫米×3米，30℃）和冷却盘管（内径0.5毫米×20厘米，0℃）组成。荧光分光光度计的波长设置为激发波长305 - 350纳米和发射波长380 - 410纳米，每种溶液的流速为1.0毫升/分钟。载流为去离子水。在0.2摩尔/升磷酸盐缓冲液（pH 6.0）中含有10毫摩尔/升过氧化氢的反应溶液对吡啶及其衍生物产生最大荧光强度。从5纳克到100纳克的吡啶及其衍生物获得了线性校准曲线。异烟酸、异烟肼和乙酰异烟肼2.5纳克（n = 10）和25纳克（n = 10）的变异系数分别为1.8%和1.1%、1.6%和1.2%、2.1%和1.4%。异烟酸的检测限（信噪比 = 3）为250皮克，异烟肼、乙酰异烟肼、烟酰胺、异烟酰胺、烟酸的检测限为500皮克，吡啶、尼古丁、2 - 甲基吡啶、2 - 甲基烟酰胺和吡啶甲酸的检测限为2.5纳克。含有有机溶剂（甲醇、乙醇或乙腈）的载流会降低荧光强度，但在乙腈的情况下降低程度比甲醇或乙醇小。该方法每小时可分析30个样品。
