Suarez-Luque Silvia, Mato Inés, Huidobro José F, Simal-Lozano Jesús, Sancho M Teresa
Facultad de Farmacia, Departamento de Química Analítica, Nutrición y Bromatología, Area de Nutrición y Bromatología, Universidad de Santiago, 15782 Santiago de Compostela, Galicia, Spain.
J Agric Food Chem. 2006 Dec 13;54(25):9292-6. doi: 10.1021/jf061536s.
A capillary zone electrophoresis method for the determination of inorganic anions and formic acid in honey samples was developed for the first time. The complete separation of chloride, nitrate, sulfate, phosphate, and formic acid was achieved with a simple electrolyte composed by 2 mM potassium dichromate as the carrier solution and background absorbance provider and 0.05 mM tetraethylenepentamine (TEPA) as electro-osmotic flow suppressor (pH 4.00). Injection was performed hydrostatically by elevating the sample at 10 cm for 10 s. The running voltage was -27 kV at 25 degrees C. Indirect UV absorption detection was achieved at 254 nm. The detection limit was in the range between 0.03 and 20 mg/kg, and the quantification limits ranged from 1.52 to 20.6 mg/kg. The calibration graphs were linear in the concentration range from the quantification limit to at least 2.5 g/kg for chloride, 0.25 g/kg for nitrate, 0.75 g/kg for sulfate, 1.50 g/kg for phosphate, and 0.75 g/kg for formic acid. Precision data in the honey samples analyzed showed repeatability and reproducibility relative standard deviations lower than 1.4 and 2.4% for migration time and lower than 1.8 and 4.3% for anion content, respectively. Recoveries of anions in honey samples analyzed ranged from 94.4 to 99.8%. Ten honey samples were analyzed to test the proposed method. Mean contents of 260.5, 3.93, 60.5, 139.4, and 209.3 mg/kg were found, respectively, for chloride, nitrate, sulfate, phosphate, and formic acid in analyzed honeys. These results agreed with literature data.
首次开发了一种用于测定蜂蜜样品中无机阴离子和甲酸的毛细管区带电泳方法。使用由2 mM重铬酸钾作为载体溶液和背景吸光剂以及0.05 mM四乙烯五胺（TEPA）作为电渗流抑制剂（pH 4.00）组成的简单电解质，实现了氯离子、硝酸根离子、硫酸根离子、磷酸根离子和甲酸的完全分离。通过将样品升高10 cm并保持10 s进行静水压进样。在25℃下运行电压为-27 kV。在254 nm处进行间接紫外吸收检测。检测限在0.03至20 mg/kg之间，定量限在1.52至20.6 mg/kg之间。校准曲线在氯离子从定量限到至少2.5 g/kg、硝酸根离子0.25 g/kg、硫酸根离子0.75 g/kg、磷酸根离子1.50 g/kg和甲酸0.75 g/kg的浓度范围内呈线性。分析的蜂蜜样品中的精密度数据显示，迁移时间的重复性和再现性相对标准偏差分别低于1.4%和2.4%，阴离子含量的相对标准偏差分别低于1.8%和4.3%。分析的蜂蜜样品中阴离子的回收率在94.4%至99.8%之间。分析了10个蜂蜜样品以测试所提出的方法。在所分析的蜂蜜中，氯离子、硝酸根离子、硫酸根离子、磷酸根离子和甲酸的平均含量分别为260.5、3.93、60.5、139.4和209.3 mg/kg。这些结果与文献数据一致。
