中性紅固體相螢光焠滅法測定食品中的微量亞硝酸鹽   全文下載

A Solid-phase Fluorescent Quenching Method for the Determination of Trace Amounts of Nitrite in Foods with Neutral Red

本文報導了一種簡單、靈敏的測定食品中微量亞硝酸鹽的方法。在這個方法中，中性紅作為螢光試劑，其與亞硝酸鹽在0.1 mol／L 鹽酸的條件下反應生成一種非螢光的化合物。被環糊精包結的中性紅其螢光可利用5 mm的石英槽來測定。激發和發射波長分別為548和609 nm。亞硝酸鹽濃度在40-200 μg／L的範圍內時，中性紅的螢光焠滅與亞硝酸鹽濃度呈線性關係。方法的檢出下限是8.1 μg／L。相對標準偏差是1.7%。常見的離子不干擾此反應。方法用于食品中亞硝酸鹽的測定，結果滿意。另外，所涉及的反應機制也被討論。

A simple and sensitive solid-phase fluorescent quenching method for the determination of trace amounts of nitrite in food samples has been developed. The method is based on the reaction between nitrite and neutral red, which is used as an emission reagent, to form a non-fluorescent compound in 0.1 mol/L hydrochloric acid. The fluorescent intensity was measured in 5-mm quartz cells with excitation and emission wavelengths of 548 and 609 nm, respectively. The degree of fluorescent quenching showed good linearity at concentrations of nitrite between the ranges of 40-200 µg/L. The detection limit is 8.1 µg/L and the RSD is 1.7%. The general coexisting ions do not interfere with the reaction of neutral red with nitrite. The proposed method was applied to the determination of trace amounts of nitrite in food samples with satisfactory results. In addition, the mechanism involved in the reaction was discussed. 本文報導了一種簡單、靈敏的測定食品中微量亞硝酸鹽的方法。在這個方法中，中性紅作為螢光試劑，其與亞硝酸鹽在0.1 mol／L 鹽酸的條件下反應生成一種非螢光的化合物。被環糊精包結的中性紅其螢光可利用5 mm的石英槽來測定。激發和發射波長分別為548和609 nm。亞硝酸鹽濃度在40-200 µg／L的範圍內時，中性紅的螢光焠滅與亞硝酸鹽濃度呈線性關係。方法的檢出下限是8.1 µg／L。相對標準偏差是1.7%。常見的離子不干擾此反應。方法用于食品中亞硝酸鹽的測定，結果滿意。另外，所涉及的反應機制也被討論。