Aguilar-Caballos M P, Gómez-Hens A, Pérez-Bendito D
Analytical Chemistry Division, Faculty of Sciences, University of Córdoba, 14004 Cordoba, Spain.
J Agric Food Chem. 2000 Feb;48(2):312-7. doi: 10.1021/jf990886u.
A simple and fast luminescent method is used for the first time to resolve a mixture of two synthetic antioxidants, propyl gallate (PG) and butylated hydroxyanisole (BHA), by the joint use of the stopped-flow mixing technique and a T-format luminescence spectrometer. The determination of these compounds involves two different and independent reactions. On the one hand, PG determination is based on an energy transfer process that involves the formation of a lanthanide chelate with terbium in the presence of Triton X-100 and tri-n-octylphosphine oxide. On the other hand, BHA is determined using a reaction between the oxidized form of Nile Blue and the antioxidant. Both systems are excited at the same excitation wavelength (310 nm), and the emission wavelengths are 545 and 665 nm for PG and BHA, respectively. The absence of overlap in the emission spectra makes it possible to measure separately the analytes in each channel of the instrument. Initial rate and equilibrium signal are used as analytical parameters and measured in 0.1 and 1 s for PG and BHA, respectively. Calibration graphs are linear over the range 0.09-3.5 microg mL(-)(1) for PG and 0.3-15 microg mL(-)(1) for BHA. The relative standard deviations of both systems are close to 2%. The proposed method is applied to the determination of these two antioxidants in several commercial food samples with recoveries ranging between 94.8 and 102.9% for PG and between 94.1 and 102.1% for BHA.
首次使用一种简单快速的发光方法，通过联用停流混合技术和T型发光光谱仪来解析两种合成抗氧化剂没食子酸丙酯（PG）和丁基羟基茴香醚（BHA）的混合物。这些化合物的测定涉及两个不同且独立的反应。一方面，PG的测定基于能量转移过程，该过程涉及在Triton X - 100和三正辛基氧化膦存在下与铽形成镧系螯合物。另一方面，BHA是利用尼罗蓝的氧化形式与抗氧化剂之间的反应来测定。两个体系在相同的激发波长（310 nm）下激发，PG和BHA的发射波长分别为545和665 nm。发射光谱没有重叠，这使得可以在仪器的每个通道中分别测量分析物。初始速率和平衡信号用作分析参数，分别在0.1 s和1 s内对PG和BHA进行测量。PG的校准曲线在0.09 - 3.5 μg mL⁻¹范围内呈线性，BHA的校准曲线在0.3 - 15 μg mL⁻¹范围内呈线性。两个体系的相对标准偏差接近2%。所提出的方法应用于几种商业食品样品中这两种抗氧化剂的测定，PG的回收率在94.8%至102.9%之间，BHA的回收率在94.1%至102.1%之间。
