Harp Bhakti Petigara, Barrows Julie N
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Cosmetics and Colors, 5100 Paint Branch Pkwy, College Park, MD 20740, USA.
J AOAC Int. 2009 Nov-Dec;92(6):1639-43.
A reversed-phase LC method was developed to determine two manufacturing intermediates in the monosulfo monoazo color additive D&C Red No. 34 and its lakes. The analytes are 2-amino-1-naphthalenesulfonic acid (Tobias acid) and 3-hydroxy-2-naphthalenecarboxylic acid (3-hydroxy-2-naphthoic acid). This method can be used for batch certification of the color additives by the U.S. Food and Drug Administration to ensure that each lot meets published specifications for coloring drugs and cosmetics. The new method uses lithium oxalate in methanol-water to dissolve the color additives for analysis. The analytes were identified by comparison of their LC retention times and UV absorption spectra with those of standards. Peak area calibrations were generally linear (R > 0.999) and recoveries were 105% for Tobias acid and 103% for 3-hydroxy-2-naphthoic acid. The limits of determination (LOD) were 0.01% for Tobias acid and 0.03% for 3-hydroxy-2-naphthoic acid. The RSDs at the specification levels were 0.9% for Tobias acid and 3.2% for 3-hydroxy-2-naphthoic acid. Survey analyses of 14 samples of certified D&C Red No. 34 straight colors and lakes from six domestic and foreign manufacturers yielded results for Tobias acid that generally agreed with results previously obtained by using a gravity elution column chromatographic method. Nine of the results for 3-hydroxy-2-naphthoic acid were 2 to 5 times higher than the results obtained using the column chromatographic method. We attribute the lower accuracy of the column chromatographic method to incomplete solubility of the samples using the method conditions and difficulty with interpreting the UV spectrophotometric results.
开发了一种反相液相色谱法，用于测定单磺基单偶氮食用色素D&C红34号及其色淀中的两种生产中间体。分析物为2-氨基-1-萘磺酸（托拜厄斯酸）和3-羟基-2-萘甲酸（3-羟基-2-萘酸）。该方法可用于美国食品药品监督管理局对食用色素的批次认证，以确保每一批次都符合公布的药品和化妆品着色规范。新方法使用草酸锂的甲醇-水溶液溶解食用色素进行分析。通过将分析物的液相色谱保留时间和紫外吸收光谱与标准品进行比较来鉴定分析物。峰面积校准通常呈线性（R>0.999），托拜厄斯酸的回收率为105%，3-羟基-2-萘酸的回收率为103%。托拜厄斯酸的测定限（LOD）为0.01%，3-羟基-2-萘酸的测定限为0.03%。在规范水平下，托拜厄斯酸的相对标准偏差（RSD）为0.9%，3-羟基-2-萘酸的相对标准偏差为3.2%。对来自国内外六家制造商的14个经认证的D&C红34号纯色和色淀样品进行的调查分析显示，托拜厄斯酸的结果与之前使用重力洗脱柱色谱法获得 的结果基本一致。3-羟基-2-萘酸的九个结果比使用柱色谱法获得的结果高2至5倍。我们将柱色谱法较低的准确度归因于该方法条件下样品的不完全溶解以及紫外分光光度法结果解释的困难。
