萘乙酸对绿豆芽维生素C的影响及其残留量的研究

采用对照培养法，探究了绿豆芽生长过程中，萘乙酸(NAA)对营养物质维生素C代谢的影响.绿豆芽用80%甲醇提取，采用高效液相色谱分离/紫外检测，建立了分析绿豆芽中NAA残留的方法.采用C18色谱柱分离， 流动相为甲醇和磷酸－氢氧化钠缓冲溶液(0.01 mol·L－1，pH＝3.0)(70∶30，V/V)组成，柱温为40 ℃，紫外检测波长220 nm.结果表明，绿豆在发芽的过程中，用NAA 处理在浓度为0.19 μg·mL－1时维生素C含量达到一个峰值.NAA在0.5～30 μg·mL－1范围内的线性关系良好，相关系数(R2)为0.999 7，检出限(S/N＝3)为0.01 μg·mL－1，加标回收率在100.2%～110.6%之间.该方法简单、快速，可实现对植物生长激素NAA的残留分析.

Study on the effect of naphthalic acetic acid on the vitamin c of mungbean sprouts and its residues

In this paper， the effects of naphthalene acetic acid (NAA) on vitamin c metabolism of mungbean sprouts were studied by using control culture. After mungbean sprouts were extracted using 80% methanol， the method for the determination of NAA residues in mungbean sprouts was established by high performance liquid chromatography with ultraviolet detection. The NAA was separated with C18 column. The methanol and phosphoric acid-sodium hydroxide buffer solution (0.01 mol·L－1， pH＝3.0) (70∶30， V/V) was used as mobile phase. The column temperature was 40 ℃， and UV detection wave length was 220 nm. The results showed vitamin c content was the highest when NAA concentration was 0.19 μg·mL－1. The linear relationship of NAA was good in the range of 0.5～30 μg·mL－1， and the correlation coefficient (R2) was 0.9997. The limit of detection of the method was 0.01 μg·mL－1， and the recovery range was between 100.2%～110.6%. The method is simple， rapid and can be used for the determination of NAA residues.