Background: Thiamine hydrochloride (THY), also known as vitamin B1, is a watersoluble vitamin usually found in food and considered as a dietary supplement and treatment in case of vitamin deficiency, for example, in malabsorption and chronic diarrhea.

Objectives: Rapid, green, and sensitive methods for the assay of vitamin B1 (thiamine hydrochloride, THY) in pharmaceutical forms, using normal and reverse flow injection manifolds and sulfonamide drugs as green and safe reagents were reported. Sulfamethoxazole and sulfadimidine drugs were used rather than toxic and expensive reagents.

Methods: nFIA and rFIA manifolds were used for automated the reaction of THY with diazotized sulfamethoxazole (DSMZ) and diazotized sulfadimidine (DSDM) in an alkaline medium, respectively. The absorbance of the resultant red-orange azo dyes was monitored spectrophotometrically at λmax494 and 496nm for both methods, respectively.

Results: The linearity of the suggested methods was in the ranges of 2 till 80 μg/mL (LOD 0.69 μg/mL, %RSD 0.32, n=6) for nFIA method and 0.5-70μg/mL (LOD 0.29 μg/mL, %RSD 0.85, n=6) for rFIA. The sampling frequency was 84 and 51 injections per hour for nFIA and rFIA methods, respectively. Chemical and physical variables for both methods were studied carefully.

Conclusion: Both flow injection modes were effectively applied in the assay of THY in its pharmaceutical forms. The results were compared with those of the standard pharmacopeia method, and the statistical analysis indicated insignificant differences in accuracy and precision between the methods.

背景：盐酸硫胺素 (THY)，也称为维生素 B1，是一种水溶性维生素，通常存在于食物中，被认为是维生素缺乏症（例如吸收不良和慢性腹泻）的膳食补充剂和治疗剂。

目标：报告了使用正流和逆流注射歧管以及磺胺类药物作为绿色安全试剂的药物形式维生素 B1（盐酸硫胺素，THY）的快速、绿色和灵敏的测定方法。使用的是磺胺甲恶唑和磺胺二甲嘧啶药物，而不是有毒且昂贵的试剂。

方法：nFIA 和 rFIA 歧管分别用于在碱性介质中自动使 THY 与重氮化磺胺甲恶唑 (DSMZ) 和重氮化磺胺二甲嘧啶 (DSDM) 反应。对于两种方法，分别在 λmax494 和 496nm 处通过分光光度法监测所得红橙色偶氮染料的吸光度。

结果：对于 nFIA 方法，建议方法的线性范围为 2 至 80 μg/mL（LOD 0.69 μg/mL，%RSD 0.32，n=6）和 0.5-70 μg/mL（LOD 0.29 μg/mL， rFIA 的 %RSD 0.85，n=6)。nFIA 和 rFIA 方法的采样频率分别为每小时 84 次和 51 次进样。仔细研究了这两种方法的化学和物理变量。

结论：两种流动注射模式都有效地应用于 THY 药物形式的分析中。结果与标准药典方法的结果进行比较，统计分析表明方法之间的准确度和精密度差异不显着。