一、前言 我们曾在土壤和植物分析所沿用的姜黄素—草酸法中,以体积较小(2×3×3厘米),排列紧凑的塑料容器代替蒸发皿,置于烘箱中脱水。由于容器减小,大大减少了受热温度上的差异,提高了分析的重现性。但由于姜黄素和草酸反应的灵敏度低,姜黄素在加热时容易分解,尤其在空气湿度大的情况下,络合物形成的反应条件难以控制,使分析的精确度和重复性差。硼酸—姜黄素在浓硫酸—醋酸中形成玫瑰花青甙比硼酸—姜黄素—草酸络合物稳定,吸光率大,灵敏度高。此法可被认为是比较标准可靠的方法。 玫瑰花甙红色络合物可直接在姜黄素—硫酸—冰醋酸中形成。由于这种络合反应必须是在强酸中姜黄素质子化才能完成,而质子化姜黄素受热遇水易分解,因此可采取将试样溶液蒸干的办法,而使络合反应在 I. Preface In the curcumin-oxalate method used in soil and plant analysis, a compact plastic container (2 × 3 × 3 cm) was used instead of the evaporating dish and placed in an oven for dehydration. As the container is reduced, the difference in the heating temperature is greatly reduced, and the analysis is more reproducible. However, due to the low sensitivity of curcumin and oxalic acid reaction, curcumin is easily decomposed when heated, especially in the case of large air humidity, the reaction conditions for complex formation are difficult to control, and the analysis accuracy and repeatability are poor. Boric acid - curcumin in concentrated sulfuric acid - acetic acid to form rosiglitazone than boric acid - curcumin - oxalate complex stability, absorbance, high sensitivity. This method can be considered as a more standard and reliable method. The rosiglitazone red complex can be formed directly in curcumin-sulfuric acid-glacial acetic acid. Because of this complexation reaction must be strong acid curcumin protonation can be completed, and the protonated curcumin easy to decompose with water, so the sample solution can be evaporated to dry, and the complex reaction in