Department of Analytical Chemistry and Foods Technology, University of Castilla-La Mancha , 13071 Ciudad Real, Spain.
J Agric Food Chem. 2013 Oct 16;61(41):9769-75. doi: 10.1021/jf403264f. Epub 2013 Oct 8.
A simple, sensitive method for determining gibberellic acid based on photochemically induced fluorescence detection was developed to determine this plant growth regulator in a technical formulation, tomato, and fruit samples. The principle for the determination is the photochemical reactivity of the gibberellic acid, being consistent with the occurrence of photoaromatization and photochemical dimerization with loss of carbon dioxide, and with the likely formation of various fluorescent photoproducts. Six min of UV (mainly at 253.7 nm) irradiation in a solution containing 50% (v/v) methanol and buffer at pH 5 provided the best results. The calibration curve was linear over the concentration range 50-150 ng mL(-1), and the limit of detection was 1.7 ng mL(-1). The method is useful to determine gibberellic acid in samples with background fluorescence such as plum and tomato without the need for labor-intensive preparation as a result of UV irradiation suppressing the fluorescent background.
建立了一种基于光化学诱导荧光检测的简单、灵敏的赤霉素测定方法，用于测定技术配方、番茄和水果样品中的这种植物生长调节剂。测定的原理是赤霉素的光化学反应性，与光芳构化和光化学二聚化以及二氧化碳的损失一致，并且可能形成各种荧光光产物。在含有 50%（体积/体积）甲醇和 pH 5 缓冲液的溶液中进行 6 分钟的 UV（主要在 253.7nm）照射可获得最佳结果。校准曲线在 50-150ng/mL 浓度范围内呈线性，检测限为 1.7ng/mL。该方法可用于测定具有荧光背景的样品中的赤霉素，如李子和番茄，由于 UV 照射抑制了荧光背景，因此无需进行繁琐的制备即可使用。
