McMullen Sarah E, Casanova John A, Gross Lois K, Schenck Frank J
U.S. Food and Drug Administration, Southeast Regional Laboratory, 60 Eighth St NE, Atlanta, GA 30309, USA.
J AOAC Int. 2005 Nov-Dec;88(6):1793-6.
An ion chromatographic method was developed for the determination of nitrate and nitrite in vegetable and fruit baby foods. The introduction of nitrate or nitrite to food may be natural or artificial as a preservative. Because of the higher pH found in babies' stomachs, nitrate can act as a reservoir for the production of nitrite by nitrate-reducing bacteria that can be harbored in the intestinal tract. This problem does not exist in adults because of the lower pH of the adult stomach. Exposure to nitrite by infants can result in methemoglobinemia (blue baby syndrome). There are also indications that carcinogenic nitrosamines can be formed from nitrates at the higher pH. These gastric conditions disappear at approximately 6 months of age. In this method, nitrate and nitrite were separated on a hydroxide-selective anion exchange column using online electrolytically generated high-purity hydroxide eluant and detected using suppressed conductivity detection. Average recoveries of spiked nitrite residue ranged from 91 to 104% and spiked nitrate residue ranged from 87 to 104%. This method and the AOAC Official Method yield comparable results for samples containing incurred nitrate residue. In addition, this method eliminates the hazardous waste associated with the use of cadmium found in the AOAC Official Method.
建立了一种离子色谱法，用于测定蔬菜和水果婴儿食品中的硝酸盐和亚硝酸盐。硝酸盐或亚硝酸盐进入食品可能是天然的，也可能是作为防腐剂人工添加的。由于婴儿胃部的pH值较高，硝酸盐可作为肠道中硝酸盐还原菌产生亚硝酸盐的储存库。由于成人胃部的pH值较低，所以这个问题在成人中不存在。婴儿接触亚硝酸盐会导致高铁血红蛋白血症（蓝婴综合征）。也有迹象表明，在较高的pH值下，硝酸盐可形成致癌的亚硝胺。这些胃部状况在大约6个月大时消失。在该方法中，硝酸盐和亚硝酸盐在氢氧根选择性阴离子交换柱上分离，使用在线电解产生的高纯度氢氧根洗脱液，并采用抑制电导检测进行检测。加标亚硝酸盐残留的平均回收率为91%至104%，加标硝酸盐残留的平均回收率为87%至104%。对于含有残留硝酸盐的样品，该方法与美国官方分析化学师协会（AOAC）官方方法所得结果相当。此外，该方法消除了AOAC官方方法中使用镉所产生的危险废物。
