婴幼儿配方乳粉中脂肪酸测定不同定量方法的差异性

Research on the differences between the different quantitative methods for the determination of fatty acid in infant formula powder

婴幼儿配方乳粉中不同脂肪酸组分定量方法在相关标准中主要有外标法与归一化法标法。通过对两种定量方法的比较研究，发现两者存在显著误差，究其原因：脂肪中各脂肪酸质量分数差异较大及分别进行外标法定量时计算所得的总脂肪酸质量分数因累计误差而导致偏低等原因，使得计算所得的各脂肪酸组分显著高于实际质量分数。经研究证明：两种方法脂肪酸组分测定结果外标法较归一化法偏高（约20％～30％）；。而归一化法计算的为相对质量分数，其测定误差远低于外标法，更接近其实际质量分数。建议采用归一化法定量测定脂肪酸组分更为准确合理。

Infant formula milk powder in different fatty acid group is divided into quantitative methods in the relevant standards are mainly external standard method and normalization method standard method. Through a comparative study of two kinds of quantitative methods and found two significant error. The reason： fat in the fatty acid mass fraction among the larger and were carried out standard quantitative method when the calculated total fatty acid mass fraction due to accumulated error and result in partial low, the calculated of the fatty acid group was significantly higher than that of the actual mass fraction. Studies prove that： two methods in the fatty acid composition of points de- termination results of external standard method with normalization method is high （about 20% -30%）. And normalization method is the rela- tive mass fraction, and the measurement error were lower than the outside standard method, closer to the actual quality scores. Suggest using normalization method for quantitative determination of fatty acid composition is more accurate and reasonable.