Departamento de Física, Química e Matemática, Universidade Federal de São Carlos - UFSCar, Sorocaba, Brazil.
Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo (USP), São Paulo, Brazil.
Electrophoresis. 2019 Nov;40(22):2929-2935. doi: 10.1002/elps.201900171. Epub 2019 Sep 8.
Aldehydes are important compounds in a large number of samples, especially food and beverages. In this work, for the first time, cyclohexane-1,3-dione (CHD) was used as a derivatizing reagent aiming aldehyde (formaldehyde, acetaldehyde, propionaldehyde, and valeraldehyde) analysis by MEKC-DAD. The optimized separation of the derivates was performed using a voltage program (+20 kV, 0-15 min.; +23 kV, 15-17 min.) at a temperature of 26°C, and using as the running buffer a mixture containing 100 mmol/L of sodium dodecyl sulfate and 29 mmol/L of sodium tetraborate at pH 9.2, with maximum absorbance at 260 nm. CHD was compared with two other derivatizing agents: 3-methyl-2-benzothiazolinone hydrazone and phenylhydrazine-4-sulfonic acid. The CHD-aldehyde derivatives were also characterized by LC-MS. The calibration curves for all aldehydes had r above 0.999 and LODs ranged from 0.01 to 0.7 mg/L. The optimized methodology was applied in sugar cane brandy (cachaça) samples successfully. CHD showed to be an alternative derivatization reagent due to its stability, aqueous solubility, high selectivity and sensitivity, reduced impurities, and simple preparation steps.
醛类是许多样品中重要的化合物，尤其是在食品和饮料中。在这项工作中，环己烷-1,3-二酮（CHD）首次被用作衍生试剂，用于通过 MEKC-DAD 分析醛（甲醛、乙醛、丙醛和正戊醛）。在 26°C 的温度下，使用包含 100mmol/L 十二烷基硫酸钠和 29mmol/L 四硼酸钠的混合物作为运行缓冲液，并在 260nm 处具有最大吸光度，通过电压程序（+20kV，0-15min；+23kV，15-17min）优化了衍生物的分离。CHD 与另外两种衍生试剂：3-甲基-2-苯并噻唑啉酮腙和苯肼-4-磺酸进行了比较。CHD-醛衍生物也通过 LC-MS 进行了表征。所有醛的校准曲线的 r 值均大于 0.999，LODs 范围为 0.01 至 0.7mg/L。优化后的方法成功应用于甘蔗白兰地（cachaça）样品。CHD 由于其稳定性、水溶性、高选择性和灵敏度、减少杂质和简单的制备步骤，因此是一种替代衍生试剂。
