采用高效液相色谱-紫外检测器测定椰油酸单乙醇酰胺和椰油酸二乙醇酰胺中的N-亚硝基二乙醇胺的含量。称取样品0.100 0 g，用甲醇（8+2）溶液溶解并定容至10.0 mL，超声10 min，经0.45 μm微孔滤膜过滤后，滤液供高效液相色谱分析。以Diamonsil C₁₈硅胶键合相色谱柱（4.6 mm×250 mm，5 μm）为固定相，以不同比例的甲醇-水体系为流动相进行梯度洗脱，采用紫外检测器在波长233 nm处进行测定。N-亚硝基二乙醇胺的质量浓度在0.05~25.00 mg·L^-1内与其峰面积呈线性关系，检出限（3S/N）和测定下限（10S/N）分别为15，48 μg·L^-1。加标回收率在94.5%~98.5%之间，测定值的相对标准偏差（n=5）在3.8%~5.9%之间。

A method of high performance liquid chromatography-ultraviolet detector was applied to determination of N-nitrosodiethanolamine in coconut oil monoethanolamide and coconut oil diethanolamide. The sample (0.100 0 g) was dissolved in methanol (8+2) solution, and the solution was made up to 10.0 mL with methanol (8+2) solution. After ultrasonically extracting for 10 min, and filtering with 0.45 μm micro filter membrane, the filtrate was analyzed by high performance liquid chromatography. Diamonsil C₁₈ silica gel bonded phase column (4.6 mm×250 mm, 5 μm) was used as stationary phase, with a mixture of methanol and water with different ratios as mobile phase for gradient elution. UV detection was carried out at the wavelength of 233 nm. Linear relationship was found between chromatogaphic peak area and mass concentration of N-nitrosodiethanolamine in the range of 0.05-25.00 mg·L^-1, with detection limit (3S/N) and the lower limit of determination (10S/N) of 15, 48 μg·L^-1, respectively. Values of recovery obtained by standard addition method were in the range of 94.5%-98.5%, and relative standard deviations (n=5) were in the range of 3.8%-5.9%.