【摘要】 目的 测定乳品中的硝酸盐。方法 用电导检测-离子色谱法测定。以碳酸钠-碳酸氢钠作淋洗液,在样品中先后加入醋酸和氢氧化钠溶液分别脱除蛋白质和脂肪等有机物,直接进样,优化了硝酸盐的离子色谱分离和测定条件。结果 方法的检出限达10μg/L（3倍信噪比）,0.1-20 mg/L和20-200 mg/L范围内线性关系良好,线性回归方程分别为Y=2.294.×10^-5X+0.110 6和Y=1.705×10^-5X+7.261,相关系数分别为r=0.9999和r=0.9996。测定了婴儿奶粉、孕产妇专用奶粉和鲜牛奶中的硝酸盐,加标回收率分别为96.8％、93.5％、108.3％。结论 用离子色谱法分离测定乳品中的硝酸盐,有较高的回收率,较好的精密度和较低的检出限。更多还原

【Abstract】 [Objective]To determine nitrate in dairy. [Methods] Conductance - hydronium chromatography method was adopted. Acetic acid and NaOH were added into the samples with the lotion of sodium carbonate - sodium bicarbonate to remove protein and fat. The condition of hydronium chromatography method was optimized. [Results]Detection limit of this method was 10 μg/L , 0.1 - 20 mg/L and 20-200 mg/L and showed good linearity. Linear regression equation was Y = 2.294 ×10^-5X +0.110 6 and Y = 1.705×10^-5 X + 7.261 respectively. Relative coefficient was r = 0.999 9 and r = 0.999 6 respectively. Nitrate in milk powder for infant and pregnant women and fresh milk was tested. The recovery rate of them was 96.8% , 93.5% and 108.3% respectively. [ Conclusion ] Hydronium Chromatography method is a good method to test nitrate in dairy with high recovery rate, accuracy and low detection limit.更多还原