Determination of sulphonated quinophthalones in Quinoline Yellow and its lakes using high-performance liquid chromatography.

Quinoline Yellow (QY, Colour Index No. 47005) is internationally used as a colour additive in foods, drugs, and cosmetics. The manufacture of QY requires sulphonating quinophthalone, and depending on the degree of sulphonation, various forms of QY result, containing different proportions of quinophthalone mono-, di-, and trisulfonic acid sodium salts (monoSA, diSA, and triSA, respectively). Regulations on the specific composition and uses of QY differ across countries with associated differences in names for QY. The QY form certified for use in the U.S. in drugs and cosmetics is known as D&C Yellow No. 10 (Y10). The Code of Federal Regulations (CFR) specifies that Y10 and its lakes consist of predominantly monoSA's, the sum of whose levels is ≥ 75%, and that the sum level of diSA's is ≤ 15%, with one of them (6'8'diSA) at ≤ 3%. The present work reports the development of an HPLC method for determining those CFR-specified values and the level of a non-CFR-specified component, 6'8'5triSA. The selected analytes, 6'SA, 6'5diSA, 6'8'diSA, and 6'8'5triSA, were quantified by using five-point-calibration curves (R2 > 0.999) with data-point ranges of 9.96-96.53%, 0.54-21.69%, 0.10-5.00%, and 0.11-5.53% by weight, respectively. The method was found to be precise (relative standard deviation values, 0.55-0.80%) and accurate (recovery values, 91.07-99.45%). LOD and LOQ values, respectively, were as follows: 1.23 and 3.70%, 6'SA; 0.42 and 1.26%, 6'5diSA; 0.11 and 0.34%, 6'8'diSA; and 0.01 and 0.04%, 6'8'5triSA. The HPLC method was applied successfully to the analysis of 20 Y10 and eight Y10 lake samples. It can be extended to other QY forms such as E104 and Yellow 203 because it enables analysis of 6'8'5triSA. This paper also addresses the implications of the varying structure depictions and CAS numbers of the QY components that are due to the existence of three tautomeric forms of quinophthalone.

Determination of fluorescein and brominated fluoresceins in the color additive D&C Orange No. 5 and its lakes using high-performance liquid chromatography.

The colour additives D&C Orange No. 5 (O5) and its lakes (O5L) are subject to batch certification by the U.S. Food and Drug Administration (FDA) to ensure compliance with specifications in the Code of Federal Regulations (CFR). The present study reports the development of a high-performance liquid chromatography (HPLC) method for the quantitative determination of seven CFR-specified components in O5 and O5L - fluorescein and six brominated fluoresceins. The analytes were quantified using six-point calibration curves with data points (w/w) that ranged as follows: 20.0-70.0% for 4',5'-dibromofluorescein; 9.8-44.1% for 2',4',5'-tribromofluorescein; 1.01-15.2% for 2',4',5',7'-tetrabromofluorescein; 0.10-3.12% for 2',4'-dibromofluorescein; 0.10-3.06% for 2',5'-dibromofluorescein; 0.11-2.85% for 4'-bromofluorescein; and 0.10-2.02% for fluorescein. For all seven analytes, the HPLC instrument response was linear (R2 > 0.999) over the tested concentration ranges and the limits of detection (0.01-1.55%) were well below the CFR-specified levels. Other validation data showed good analyte recovery (87.91-101.73%) as well as method precision measured by the relative standard deviation (0.53-1.56%). The new method was applied to the analysis of test portions from 15 batches of O5 and eight batches of O5L submitted to FDA for certification by domestic and foreign manufacturers. Compared to the thin-layer chromatography/spectrophotometric procedure currently used for routine batch-certification analyses, the new method was found to be more sensitive, simpler to implement, and significantly faster, requiring 25 minutes rather than six hours to analyse one sample.

Body mass index modifies bladder cancer risk associated with low estrogen exposure among Egyptian women after menopause.

PURPOSE: Investigators have reported inconsistent findings regarding associations between body mass index (BMI) and bladder cancer risk, and they have postulated that sex steroids mediate such associations. We assessed the impact of BMI on the relationship between bladder cancer risk and combinations of age at first childbirth, parity, and age at menopause, among Egyptian women. METHODS: We used data from our multicenter case-control study of 419 cases and 786 controls in logistic regression models to estimate adjusted odds ratios (AORs) and 95% confidence intervals (CIs) of such associations. RESULTS: Age > 18 years at first childbirth and parity ≤ 6 were significantly associated with bladder cancer risk, which was higher when both factors (AOR = 2.31, 95% CI = 1.55-3.43) and age at menopause < 45 years (AOR = 3.51, 95% CI = 1.88-6.55) were present. Early menopause was associated with higher bladder cancer risk in obese (AOR = 2.90, 95% CI = 1.40-5.98) but not normal weight women (AOR = 0.98, 95% CI = 0.58-1.65; Pinteraction = 0.11), and the risk was greatest when both first childbirth at age > 18 years and parity ≤ 6 were present (AOR = 7.60, 95% CI = 1.84-31.35); however, overweight and obesity were associated with significantly lower bladder cancer risk (AOR = 0.59, 95% CI = 0.43-0.81, and AOR = 0.26, 95% CI = 0.18-0.38, respectively). CONCLUSION: Body mass index appears to modify bladder cancer risk in Egyptian women after menopause by slightly enhancing the risk associated with low estrogen exposure among the obese only. Longitudinal studies of the BMI role in bladder malignancy in this distinctive population are required.

Identification of 1',5'-naphthyridinophthalone and its quantification in the color additive D&C Yellow No. 10 (Quinoline Yellow) using high-performance liquid chromatography.

The present work reports the identification and characterization of a contaminant, 2-(2'-(1,5-naphthyridinyl))-1,3-indanedione (1',5'-naphthyridinophthalone, 1,5NP), in the color additive D&C Yellow No. 10 (U.S.-certifiable form of Quinoline Yellow), together with its quantification in batches of the color additive certified by the U.S. Food and Drug Administration (USFDA). The impurity, which is a compound not previously reported in the literature, was synthesised and characterised for use as a reference material. Test portions from 26 certified batches of D&C Yellow No. 10 submitted to USFDA by four domestic and four foreign manufacturers were analyzed for 1,5NP using high-performance liquid chromatography. The results revealed a wide range of 1,5NP levels across batches, with 18 (69.2%) of the test portions containing amounts from 0.32 to 169.94 µg g-1 while the remaining test portions contained no detectable (<0.07 µg g-1) amounts. Samples of the European and Japanese forms of Quinoline Yellow were also analyzed and found to contain a wide range of 1,5NP levels. The varying levels of 1,5NP in all three forms of Quinoline Yellow suggest that contamination can be significantly decreased or eliminated through manufacturing adjustments. Since 1,5NP is closely related to a D&C Yellow No. 10 contaminant (quinophthalone) that has a USFDA-specified limit of 4 µg g-1 and is a known allergen, assessment of the possible allergenicity of 1,5NP is warranted.

Determination of Sudan I and a newly synthesized Sudan III positional isomer in the color additive D&C Red No. 17 using high-performance liquid chromatography.

Specifications in the Code of Federal Regulations for the color additive D&C Red No. 17 (Colour Index 26100) limit the levels of two subsidiary colors, 1-(phenylazo)-2-naphthol (Sudan I) and 1-[[2-(phenylazo)phenyl]azo]-2-naphthalenol (Sudan III o-isomer), to 3% and 2%, respectively. The present work reports the development of a high-performance liquid chromatography (HPLC) method for the quantitative determination of these subsidiary colors. Since Sudan III o-isomer needed to be synthesized for use as a reference material, a two-step procedure was devised: (i) preparative-scale synthesis of the intermediate 2-aminoazobenzene (2AAB) and its purification by counter-current chromatography and (ii) diazotization of 2AAB and coupling with 2-naphthol. Characterization of the newly synthesized Sudan III o-isomer is also reported. Sudan I and Sudan III o-isomer were quantified by using five-point calibration curves with data points ranging from 0.108 to 3.240% and 0.077 to 2.227% by weight, respectively. The HPLC method is rapid (14 min for the total analysis cycle) and simple to implement. It was applied to the analysis of test portions from 25 batches of D&C Red No. 17 submitted to the U.S. Food and Drug Administration (USFDA) for certification, and it has recently been implemented by USFDA for routine batch certification of that color additive.