Bradley E L, Speck D R, Read W A, Castle L
Central Science Laboratory, Department for Environment, Food and Rural Affairs, Sand Hutton, York YO41 1LZ, UK.
Food Addit Contam. 2004 Dec;21(12):1179-85. doi: 10.1080/02652030400023093.
An analytical method for the determination of the nylon-6 monomer caprolactam in foods is described. The foodstuff was extracted with ethanol: water (1:2) containing capryllactam as internal standard and the extract was defatted using hexane. The extract was analysed by liquid chromatography coupled with mass spectrometry. The test method was calibrated down to 0.7 mg kg(-1). The repeatability of the method was good, with a relative standard deviation of 9% at the 15 mg kg(-1) level. The method was demonstrated to be accurate in an independent external check sample exercise. The new method was applied to the analysis of 50 retail foodstuffs packaged in nylon-6. Caprolactam was detected and confirmed in nine of the 50 food samples, in the range 2.8-13 mg kg(-1). The presence of caprolactam was indicated in a further 15 samples, in the range 0.8-11 mg kg(-1), but these samples did not meet all of the five confirmation criteria applied. All migration levels (both confirmed and unconfirmed) were below the European specific migration limit for caprolactam, which is 15 mg kg(-1). The average migration for all 50 samples, setting non-detectables at half the limit of detection, was 2.6 mg kg(-1) with a standard deviation of 3.1 mg kg(-1) (n = 50). All samples found to contain detectable levels of caprolactam migration were for applications involving heating the food in the packaging. They were packs of, for example, sausage meat for which the food would have been heat processed in the nylon casing, or they were nylon pouches for heating foods by boiling, microwaving or roasting.
本文描述了一种测定食品中尼龙6单体己内酰胺的分析方法。食品用含有己酰内酰胺作为内标的乙醇：水（1:2）进行萃取，萃取液用己烷脱脂。萃取液采用液相色谱-质谱联用仪进行分析。该测试方法的校准下限为0.7 mg kg⁻¹。该方法的重复性良好，在15 mg kg⁻¹水平下相对标准偏差为9%。在一次独立的外部检验样品实验中证明了该方法的准确性。该新方法应用于50种尼龙6包装的零售食品的分析。在50个食品样品中的9个中检测到并确认了己内酰胺，含量范围为2.8 - 13 mg kg⁻¹。另外15个样品中也显示出己内酰胺的存在，含量范围为0.8 - 11 mg kg⁻¹，但这些样品未满足所应用的五项确认标准。所有迁移水平（包括已确认和未确认的）均低于己内酰胺的欧洲特定迁移限量，即15 mg kg⁻¹。所有50个样品的平均迁移量（将未检出值设定为检测限的一半）为2.6 mg kg⁻¹，标准偏差为3.1 mg kg⁻¹（n = 50）。所有被发现含有可检测水平己内酰胺迁移量的样品均用于涉及在包装中加热食品的应用。例如，有包装香肠肉的包装，食品在尼龙肠衣中经过热处理；或者是用于通过煮沸、微波或烘烤加热食品的尼龙袋。
