2,3,4-三甲氧基苯甲醛标准样品的制备和定值研究

研究了2,3,4-三甲氧基苯甲醛标准样品的制备、均匀性和稳定性及其定值试验。标准样品采用工业级2,3,4-三甲氧基苯甲醛产品经亚硫酸氢钠加成反应和乙醇重结晶相结合的方法制备。测得熔点为37.8～39.6℃,经红外光谱和核磁共振分析结构与2,3,4-三甲氧基苯甲醛相吻合。标准样品的含量测定采用气相色谱面积归一化法,并通过了均匀性检验和稳定性检验(6个月)。经定值检测,2,3,4-三甲氧基苯甲醛标准样品的含量值为99.48%,不确定度(99%置信率)为0.07%。

Study on Preparation and Certification of Reference Substance of 2,3,4-Trimethoxybenzaldehyde

Preparation, homogeneity, stability and certification of reference substance of 2,3,4-trimethoxybenzaldehyde were studied. The reference substance of 2,3,4-trimethoxybenzaldehyde was prepared from an industrial grade product of 2,3,4-trimethoxybenzaldehyde by NaHSO₃ addition reaction followed by re-crystallization in ethanol. The melting point of product was 37.8-39.6℃. The structure was conformed by IR and NMR spectra. The content of 2,3,4-trimethoxybenzaldehyde in reference substance was measured by gas chromatographic area normalization. The reference substance of 2,3,4-trimethoxybenzaldehyde passed the test of homogeneity, and it was stable during 6 months at least. Through valuation test, 2,3,4-trimethoxybenzaldehyde content of the reference substance was 99.48% with uncertainty of 0.07% and confidence coefficient of 99%.