中文摘要：

建立了离子排斥色谱-紫外检测测定奶粉中双氰胺的方法,并用离子色谱-质谱进行验证.样品分别用水（固液比为1∶2）和乙腈（固液比为1∶8）振摇后,离心分离过0.22 μm微膜,直接进离子排斥柱（IonPac（R）ICE-AS1,250 mm×9 mm,5μm）分离,采用3 mmol/L甲酸-乙腈（3∶2,V/V）的混合液为流动相,流速为0.8 mL/min,检测波长220 nm,柱温为30℃.结果表明,双氰胺的浓度在50 μg/L ～0.3 g/L范围内的相关系数r=0.9999,检出限（S/N≥3）为12.5 ng/mL.添加浓度水平为500 ng/g,0.5 mg/g和3.6 mg/g时,方法的回收率在97.6％ ～ 100％之间,相对标准偏差为0.8％.

英文摘要：

A method for determination of dicyandiamide in milk powder by ion exclusion chromatography-UV detection （IEC-UV） was developed and was verified by ion chromatography-mass spectrometry （IC-MS）. Sample was extracted with water （solid-liquid ratio of 1：2） and acetonitrile （solid-liquid ratio of 1：8 ） with shaking. After centrifuging for 20 min at 10000 r/min, the supertant was filtered through a 0.22-μm syringe membrane filter and then injected into chromatograph. The chromatographic separation of dieyandiamide was performed on an IonPac ： emoji ： ICE-AS1 column （ 250 mm × 9 mm, 5μm ）. The mobile phase was the mixture of 3 mmol/L formic acid and acetonitrile at the ratio of 3 ： 2 with a flow rate of 0.8 mL/min. The detection wavelength was set at 220 nm, and the column temperature was maintained at 30 ~C. The results showed that the calibration curve of dieyandiamide was linear in the range of 50 txg/L- 0.3 g/L with a correlation coefficient of 0. 9999. The limit of detection, based on a signal-to-noise ratio of 3 ： 1, was 12.5μg./L. The average recoveries were in the rang of 97.6%-100% with the spiked levels at 500 ng/g, 0.5 mg/g and 3.6 mg/g, respectively, and the relative standard deviation was 0.8% .