催化光度法测定肉制品中亚硝酸盐

CATALYTIC PHOTOMETRIC DETERMINATION OF NITRITES IN MEATS

基于亚硝酸根 (NO-2 )在稀磷酸溶液中催化依文思蓝 -氯酸钾氧化还原反应 ,建立了微量 NO-2 的催化光度法。在最大吸收波长 61 0 nm处 ,NO-2 在 0～ 3.0 μg/2 5ml范围内呈线性关系 ,检出下限为 3.51× 1 0 -9g· ml-1。方法用于肉制品中 NO-2 的测定 ,结果满意 。

It is found that the oxidation reduction reaction between Evan′s blue and potassium chlorate is catalyzed by nitrite ion in a dilute phosphoric acid medium. A thorough study is made on the optimum conditions for this catalytic reaction and based on these facts a sensitive method for the determination of nitrites in meats is proposed. The absorption maxima is found to lie at 610nm and Beer′s law is obeyed in the concentration range of 0~3μg of NO - 2 per 25ml with a detection limit of 3.5×10 -9 g·ml -1 . The analytical results obtained by this method checked very well with those obtained by the national standard method.