A survey on the subsidiary colors (Fig. 1), raw materials, and their impurities (Fig. 2) in Food Red No. 2 (amaranth, R2) and Food Red No. 102 (new coccnin, R102) was conducted for the international harmonization regarding the specifications of coal-tar dyes. The analytical results of subsidiary colors in commercial R102 (10 samples of five manufactures) were 0.038〜0.823%, 0.060〜0.324%, 0.008〜0.169%, ND〜0.279%, and 0.07〜0.100%, for Sub A (trisodium salt of 7-hydroxy-8 (6-sulfonaphthyl-2-azo)-1,3-naphthalenedisulfonic acid), Sub B (disodium salt of 4-amino-3-(4-sulfonaphthyl-1-azo)-1-naphthalenesulfonic acid), P6R (pnceau 6R, tetrasodium salt of 7-hydroxy-8-(4-sulfonaphthylazo)-1,3,6-naphthalenetrisulfonic acid), R2, and FRE (fast red E, disodium salt of 6-hydroxy-5-(4-sulfonaphthylazo)-2-naphthalenesulfonic acid), respectively, as showed in Table 1. In one sample (A2), total content of subsidiary colors was 1% which was equal to limit valur of JECFA Specifications. The analytical results of materials and the impurities were 0.005〜0.044%, 0.052〜0.284%, 0.013〜0.196% for TS (trisodium salt of 7 hydroxy-1,3,6-naphthalenetrisulfonic acid), GS (G salt, disodium salt of 7 hydroxy-1,3-naphthalenedisulfonic acid), and NA (naphthionic acid, sodium salt of 4-amino-1-naphthalenesulfonic acid), respectively, and RS (R salt, disodium salt of 3-hydroxy-2,7-naphthalenedisulfonic acid) and SS (Schaeffer's salt, sodium salt of 6-hydroxy-2-naphthalenesulfonic acid) were not detected, as showed in Table 2. All of the samples showed percentages lower than 5%, the maximum limit regulated by JECFA for materials and their impurities. The analytical results of subsidiary colors in commercial R2 (12 samples of two manufactures) were 0.015〜0.773%, 0.219〜1.064%, ND〜0.032%, 0.029〜0.050%, and 0.057〜0.661%, for Sub B, Sub C, P6R, R102, and FRE, respectively as showed in Table 1. THe analytical results of the materials and their impurities wre 0.011〜0.075%, ND〜0.007%, 0.004〜0.072%, 0.052〜0.147%, and ND〜0.011%, for TS, GS, RS, NA, and SS, respectively, as showed in Table 2. All the samples showed percentages that were lower than 3%, which was the maximum limit regulated by JECFA for subsidiary colors, and 0.5%, which was the maximum limit regulated for materials and their impurities. Since the contents of Sub A, Sub B, and Sub C were higher than those of known subsidiary (P6R, FRE, R2 and R102) colors in some cases, it seemed necessary to specify also Sub A, Sub B, and Sub C, which were clarified in the previous report, on evaluating the specifications.
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