Batch Certification Research Articles

LB-CLAS: Lattice-based conditional privacy-preserving certificateless aggregate signature scheme for VANET

The rapid development of vehicular ad-hoc networks (VANETs) has brought great convenience to intelligent transportation, and the secure transmission of information in VANETs has become a serious problem. In addition, the protection of private information of vehicles is also a key issue. Aiming at the problem of how to guarantee the secure transmission of information in VANETs under the condition of satisfying security and privacy, we propose a lattice-based conditional privacy-preserving certificateless aggregate signature scheme (LB-CLAS) for VANETs. Instead of using Number Theory Research Unit (NTRU) lattices and discrete Gaussian sampling, the proposed LB-CLAS scheme is based on algebraic lattice. In addition, based on the module version of Small Integer Solution (MSIS) and module version of Learning With Error (MLWE) hard problems, we prove that the LB-CLAS scheme is existential unforgeability under adaptively chosen message attacks (EUF-CMA). Our LB-CLAS scheme employs individual signature verification in vehicle-to-vehicle (V2V) mode, while utilizing aggregate signatures and batch verification in vehicle-to-infrastructure (V2I) mode, with slightly differing transmission parameters between the two modes. Based on Dilithium, our LB-CLAS scheme solves the problem of high storage overhead and computational cost of existing schemes. The performance analysis shows that our LB-CLAS scheme is more efficient in terms of computation cost, storage overhead, and power consumption compared to existing schemes. Compared with existing schemes, our LB-CLAS scheme reduces the signature and verification overheads by more than 17.6% and 43.4%, respectively. Our LB-CLAS program also has significant advantages in batch verification. As the number of vehicles increases, our batch certification time cost is reduced by more than 90%. In addition, our LB-CLAS scheme has the smallest signature length, with a signature size that is 1X smaller than the most efficient existing scheme for the same level of security.

Batch certification document Certificate of Analysis / Certificate of Compliance

Batch certification document Certificate of Analysis / Certificate of Compliance

Mercury Determination in Certifiable Color Additives Using Thermal Decomposition Amalgamation and Atomic Absorption Spectrometric Analysis.

Color additives requiring batch certification by the U.S. Food and Drug Administration have Code of Federal Regulations (CFR) specification limits for certain elements and are usually analyzed by X-ray fluorescence spectrometry (XRF). However, sensitivity for Hg is too low in some color additives. The thermal decomposition amalgamation (TDA)-atomic absorption spectrometric (AAS) technique was investigated for providing quick and accurate determinations of Hg in certifiable color additives. Tests were performed to optimize conditions and test reliability of Hg determinations at and below the CFR specification limit of 1 mg/kg. Sensitivity is much improved over XRF, with limits of quantitation of 0.03 mg/kg for highly homogeneous color additives. The TDA-AAS method can be used for determining Hg concentrations at and below the CFR specification limit. The technique is effective for all color additives, including those that are difficult to analyze by XRF, but less efficient for color additives that quickly deteriorate the catalyst. Regular quality checks using certified reference materials and in-house matrix-matched check standards are essential. The TDA-AAS method is applicable for use in routine color additive batch certification. Certain matrixes (notably those that release nitrogen or sulfur oxides or halogens upon combustion) necessitate more frequent replacement of the catalyst and recalibration, impacting productivity. Color additives containing BaSO4, in color additive lakes, that are difficult to analyze by other techniques, are well suited for TDA-AAS analysis.

An ultra light weight and secure RFID batch authentication scheme for IoMT

As an application of IoT technology in the healthcare industry, IoMT has higher security requirements than IoT while improving medical efficiency and reducing medical costs. How to ensure the safety of IoMT is a challenging task. In the implementation of IoMT, Radio-Frequency Identification (RFID) is a key technology for establishing an identity authentication system, which can efficiently identify medical equipment and patients. Designing a safe and efficient RFID authentication protocol will help protect user privacy, enhance the security of the IoMT system and improve the efficiency of medical staff to detect and manage patients. Most of the existing RFID authentication protocols can only authenticate one tag in each authentication session, which is called a per-tag protocol. In medical scenarios that need to efficiently authenticate a mass of tags at short notice, the use of traditional per-tag protocols is inefficient and may delay the treatment of patients. To solve the problem that the per-tag protocols are not applicable in some medical scenarios, we designed a low-cost batch authentication protocol which can accurately identify each illegal tag and reduce the overhead of authentication data transmission. We use the solution of homogeneous linear equations as a key to encrypt the authentication data of the tag to further reduce the cost of the tag. The protocol proposed in this paper is capable of batch certification of tags, with strong security and low tag cost. After security analysis and performance analysis, our scheme can be well applied to IoMT.

Sustainable food colours

Sustainable food colours

Arsenic and Lead Determination in D&C Red No. 6 Lakes and D&C Red No. 7 Lakes Containing Barium Sulfate Using X-Ray Fluorescence Spectrometry.

Color additives requiring batch certification by the U.S. Food and Drug Administration have Code of Federal Regulations (CFR) specification limits for certain elements and are usually analyzed by x-ray fluorescence spectrometry (XRF). However, analysis of some color additives presents difficulties. An XRF method was developed for quickly determining whether barium sulfate-containing color additives certifiable as D&C Red No. 6 lakes and D&C Red No. 7 lakes meet the CFR specifications for arsenic (As) and lead (Pb). Difficulties in preparing XRF standards and analyzing As and Pb in matrices with the heavy x-ray absorber barium (Ba) were overcome by first preparing As- and Pb-fortified cellulose, then blending color additive samples with fortified and unfortified cellulose to produce XRF calibration materials. Satisfactory compensation for changes in intensity caused by Ba absorption was achieved by measuring varying concentrations of As and Pb at several concentrations of Ba. Test samples of barium sulfate-containing D&C Red No. 6 lakes and D&C Red No. 7 lakes were analyzed by the XRF method and by an inductively coupled plasma-mass spectrometry (ICP-MS) method. The ICP-MS method poses some difficulties and is time consuming. In contrast, the XRF method requires very little sample preparation, is nondestructive, uses calibrations that are stable for long periods of time, and offers acceptable determination limits (1 mg/kg As, 4 mg/kg Pb) which are less than the CFR specification limits (3 mg/kg As, 20 mg/kg Pb). The new XRF method is applicable for use in routine batch certification.

Determination of Seven Manufacturing Impurities in FD&C Red No. 40 by Ultra-High-Performance Liquid Chromatography.

The U.S. Food and Drug Administration batch-certifies color additives to ensure that each lot meets published specifications for coloring food, drugs, and cosmetics. An ultra-high-performance LC (UHPLC) method was developed to determine seven manufacturing impurities in the monoazo color additive FD&C Red No. 40 (R40). The analytes consist of two intermediates, an impurity originating from one intermediate, a reaction by-product, and three subsidiary colors. The intermediates are 4-amino-5-methoxy-2-methylbenzenesulfonic acid [cresidine-p-sulfonic acid (CSA)] and 6-hydroxy-2-naphthalene sulfonic acid sodium salt (SS). The impurity originating from the intermediate SS is 6,6'-oxybis[2-naphthalenesulfonic acid] disodium salt. The reaction by-product is 4,4'-(diazoamino)bis[5-methoxy-2-methylbenzenesulfonic acid disodium salt. The subsidiary colors are sodium salts of CSA coupled with 2-naphthol-3,6-disulfonic acid, 2-naphthol-6,8-disulfonic acid, or 2-naphthol. Samples of R40 were dissolved in an ammonium acetate buffer modified to pH 9.2, filtered, and analyzed by UHPLC. Quantitation of the analytes was performed by calibration in the presence of the color additive matrix. UHPLC validation studies showed linear calibration curves (R2 = 0.9999), good recovery (95-121%) and precision (RSDs = 1.0-6.3%), and LOQs ranging from 0.002 to 0.030%. Survey analyses of 31 samples from 11 manufacturers yielded results by the new UHPLC method and a previously used HPLC method that are consistent within experimental error. The new UHPLC method provides faster analysis time, improved separation, and similar sensitivity compared to the HPLC method. An UHPLC method was developed and validated to determine seven manufacturing impurities in R40 submitted to the FDA for batch certification.

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

ABSTRACTThe 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 4ʹ,5ʹ-dibromofluorescein; 9.8–44.1% for 2ʹ,4ʹ,5ʹ-tribromofluorescein; 1.01–15.2% for 2ʹ,4ʹ,5ʹ,7ʹ-tetrabromofluorescein; 0.10–3.12% for 2',4ʹ-dibromofluorescein; 0.10–3.06% for 2ʹ,5ʹ-dibromofluorescein; 0.11–2.85% for 4ʹ-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.

Determination of Unsulfonated Aromatic Amines in FD&C Yellow No. 5 and FD&C Yellow No. 6 by Liquid Chromatography-Triple Quadrupole Mass Spectrometry.

Background: This paper describes a simple and sensitive ultra-HPLC-triple quadrupole MS (LC-MS/MS) method for the determination of six unsulfonated aromatic amines in the color additives FD&C Yellow No. 5 (Y5) and FD&C Yellow No. 6 (Y6). The six amines determined by this method are aniline (ANL), benzidine (BNZ), 4-aminobiphenyl (4ABP), 4-aminoazobenzene (4AAB), 2-aminobiphenyl (2ABP), and 4-aminobenzonitrile (4ABN). Objective: This method is intended for use in batch certification of the color additives by the U.S. Food and Drug Administration (FDA) to ensure that each lot meets published specifications for coloring foods, drugs, and cosmetics. Methods: A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure is used for extraction of the amines. Quantitative determination was performed in electrospray positive ionization and multiple-reaction monitoring modes. Results: Validation of the method demonstrated overall recovery of 101-115% and precision of 1.74-9.78% for all analytes. Excellent regression coefficients were obtained, with values >0.999. Conclusions: The validated method was successfully used for the analyses of 30 Y5 and Y6 samples and provided results that are consistent with results from the current method used by FDA, with greater sensitivity and low matrix effects. Highlights: The validation results demonstrate that the new LC-MS/MS method is applicable for use in routine batch certification.

Challenges of manufacturing site in batch certification and release in European Union

A comprehensively designed Pharmaceutical Quality System (PQS) incorporating Good Manufacturing Practice and Quality Risk Management implemented, maintained and continuously improved, allows a consistent delivery of products with appropriate quality attributes. The manufacturer in the third country and the batch certification and release site in EU belong to the same organization operating under a corporate Pharmaceutical Quality System. A signed Quality Agreement between both parties provides improvement of the Pharmaceutical Quality System and continual maintenance of the quality of the medicinal product throughout its shelf life. This paper outlines the role and the challenges of the manufacturing site in third country within the process of batch certification and release in EU (by EU QP) and also highlights the importance of the technically justified approach including Quality Risk Management process regarding sampling in third country. Through a Technical justification for sampling including Quality Risk Assessment, it is considered that the samples taken from the manufacturing site in third country ensure representation of the whole batch. Technical justification is performed periodically to identify and manage any risks associated with this approach, thus ensuring the quality, safety and efficacy according Marketing Authorization. Keywords: batch release in EU, third country, Pharmaceutical Quality System, QP

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

ABSTRACTSpecifications 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.

Lack of genotoxicity in vivo for food color additive Allura Red AC

Allura Red AC is an approved food color additive internationally with INS number 129, in the United States as food color subject to batch certification “Food, Drug, and Cosmetic” (FD&C) Red No. 40, and in Europe as food color additive with E number 129. In their evaluation of the color (2013), the European Food Safety Authority (EFSA) expressed concerns of potential genotoxicity, based primarily on one genotoxicity study that was not conducted according to Guidelines. The present in vivo genotoxicity study was conducted according to OECD Guidelines in response to EFSA's request for additional data. The animal species and strain, and the tissues examined were selected specifically to address the previously reported findings. The results show clear absence of genotoxic activity for Allura Red AC, in the bone marrow micronucleus assay and the Comet assay in the liver, stomach, and colon. These data addressed EFSA's concerns for genotoxicity. The Joint WHO/FAO Committee on Food Additives (JECFA) (2016) also reviewed the study and concluded that there is no genotoxicity concern for Allura Red AC. Negative findings in parallel genotoxicity studies on Tartrazine and Ponceau 4R (published separately) are consistent with lack of genotoxicity for azo dyes used as food colors.

Lack of genotoxicity in vivo for food color additive Tartrazine

Tartrazine is approved as a food color additive internationally with INS number 102, in the United States as food color subject to batch certification “Food, Drug, and Cosmetic” (FD&C) Yellow No. 5, and in Europe as food color additive with E number 102. In their evaluation of the color (2013), the European Food Safety Authority (EFSA) expressed concerns of potential genotoxicity, based primarily on one genotoxicity study that was not conducted according to Guidelines. The present in vivo genotoxicity study was conducted according to OECD Guidelines in response to EFSA's request for additional data. The animal species and strain, and the tissues examined were selected specifically to address the previously reported findings. The results of this study show clear absence of genotoxic activity for Tartrazine, in the bone marrow micronucleus assay and the Comet assay in the liver, stomach, and colon. These data addressed EFSA's concerns for genotoxicity. The Joint WHO/FAO Committee on Food Additives (JECFA) (2016) also reviewed these data and concluded that there is no genotoxicity concern for Tartrazine. Negative findings in parallel genotoxicity studies on Allura Red AC and Ponceau 4R (published separately) are consistent with lack of genotoxicity for azo dyes used as food colors.

Determination of Organic Impurities in Anthraquinone Color Additives D&C Violet No. 2 and D&C Green No. 6 by Ultra-High Performance Liquid Chromatography.

A new practical and time-saving ultra-high performance liquid chromatography (UHPLC) method has been developed for determining the organic impurities in the anthraquinone color additives D&C Violet No. 2 and D&C Green No. 6. The impurities determined are p-toluidine, 1-hydroxyanthraquinone, 1,4-dihydroxyanthraquinone, and two subsidiary colors. The newly developed UHPLC method uses a 1.7-μ particle size C-18 column, 0.1 M ammonium acetate and acetonitrile as eluents, and photodiode array detection. For the quantification of the impurities, six-point calibration curves were used with correlation coefficients that ranged from 0.9974 to 0.9998. Recoveries of impurities ranged from 99 to 104%. Relative standard deviations ranged from 0.81 to 4.29%. The limits of detection for the impurities ranged from 0.0067% to 0.216%. Samples from sixteen batches of each color additive were analyzed, and the results favorably compared with the results obtained by gravity-elution column chromatography, thin-layer chromatography, and isooctane extraction. Unlike with those other methods, use of the UHPLC method permits all of the impurities to be determined in a single analysis, while also reducing the amount of organic waste and saving time and labor. The method is expected to be implemented by the U.S. Food and Drug Administration for analysis of color additive samples submitted for batch certification.

Application of high‐energy polarized energy‐dispersive x‐ray fluorescence spectrometry to the determination of trace levels of As, Hg, and Pb in certifiable color additives

Advances in x‐ray fluorescence (XRF) using high‐energy polarized energy‐dispersive (ED)XRF spectrometry (PEDXRF) were applied to the determination of trace As, Hg, and Pb in various color additives subject to batch certification by the U.S. Food and Drug Administration (FDA). The objectives of this study were to simplify sample preparation for quantitative determination of these elements and, if possible, to achieve improved sensitivity and detection limits compared to techniques currently used for certification. PEDXRF was compared with wavelength‐dispersive x‐ray fluorescence spectrometry (WDXRF) and inductively coupled plasma – mass spectrometry (ICP‐MS) for the analysis of trace levels of As, Hg, and Pb in certifiable color additives. For these light matrices, PEDXRF provided better signal‐to‐noise and allowed quantitation in smaller amounts of color additive relative to WDXRF and equal or better precision to ICP‐MS. Determination of these trace elements in a variety of color additives was possible relative to calibrations generated from one color additive using specimens prepared simply by pouring the color additive powder into an XRF sample cup. Published 2016. This article is a U.S. Government work and is in the public domain in the USA

Ultra-Performance Liquid Chromatographic Determination of Manufacturing Intermediates and Subsidiary Colors in D&C Red No. 6, D&C Red No. 7, and Their Lakes.

An ultra-performance LC (UPLC) method was developed to determine the manufacturing intermediates and subsidiary colors in the monosulfo monoazo color additives D&C Red No. 6 and D&C Red No. 7 and their lakes. This method is intended for use in 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 intermediates are 2-amino-5-methylbenzenesulfonic acid (PTMS) and 3-hydroxy-2-naphthalenecarboxylic acid (3-hydroxy-2-naphthoic acid). The subsidiary colors are 3-hydroxy-4-[(4-methylphenyl)azo]-2-naphthalenecarboxylic acid (unsulfonated subsidiary color) and 1-[(4-methylphenyl) azo]-2-naphthalenol (4-methyl Sudan I). The analytes were identified by comparing their UPLC retention times and UV-Vis absorption spectra with those of standards. Validation studies showed that calibration curves were linear (average R2=0.9994), and recoveries were 96-106%. Average LOD was 0.0014-0.0061% and average LOQ was 0.0047-0.020%. Results for RSD at the specification levels ranged from 0.67 to 5.79%. Survey analyses of 42 samples from 14 domestic and foreign manufacturers yielded results by the new UPLC method and a previously reported HPLC method that were consistent within experimental error. The new UPLC method provided increased sensitivity, faster analysis times, and improved separations compared to the HPLC method.

Subsidiary colors in D&C Red No. 34 and its lakes: Synthesis, structural characterization, and analysis by ultra-performance liquid chromatography

Abstract D&C Red No. 34 is the calcium salt of 3-hydroxy-4-[(1-sulfo-2-naphthalenyl)azo]-2-naphthalenecarboxylic acid. Its lakes are insoluble pigments formed by precipitating the dye anion onto an insoluble substratum, typically rosin. Subsidiary colors are colored impurities that are positional isomers of the dye anion or have higher or lower numbers of substituent groups. D&C Red No. 34 and its lakes are color additives listed in the U.S. Code of Federal Regulations (CFR) for use in externally applied drugs and cosmetics. These color additives are required to be batch certified by the U.S. Food and Drug Administration (FDA) to ensure compliance with the CFR requirements, including a limit of not more than four percent subsidiary colors in the straight color. There is no specified limit for subsidiary colors in the lakes, but the impurities may be analyzed for compliance with good manufacturing practices. In this paper, the syntheses of seven D&C Red No. 34 subsidiary colors are reported. Various combinations of impurities in the two intermediate starting materials for the dye, 2-amino-1-naphthalenesulfonic acid and 3-hydroxy-2-naphthalenecarboxylic acid, were used to synthesize the new compounds, which were purified by recrystallization and fully characterized by elemental analysis, ultra-performance liquid chromatography (UPLC), nuclear magnetic resonance spectroscopy, infrared spectroscopy, and visible spectrophotometry. The new compounds were used as reference materials in UPLC analyses of test samples from 33 certified lots of D&C Red No. 34 and its lakes. FDA is currently using these new reference materials for batch certification of the color additives.

Preparation of two novel monobrominated 2-(2′,4′-dihydroxybenzoyl)-3,4,5,6-tetrachlorobenzoic acids and their separation from crude synthetic mixtures using vortex counter-current chromatography

The present work describes the preparation of two compounds considered to be likely precursors of an impurity present in samples of the color additives D&C Red No. 27 (Color Index 45410:1) and D&C Red No. 28 (Color Index 45410, phloxine B) submitted to the U.S. Food and Drug Administration for batch certification. The two compounds, 2-(2′,4′-dihydroxy-3′-bromobenzoyl)-3,4,5,6-tetrachlorobenzoic acid (3BrHBBA) and its 5′-brominated positional isomer (5BrHBBA), both not reported previously, were separated from synthetic mixtures by vortex counter-current chromatography (VCCC). 3BrHBBA was prepared by chemoselective ortho-bromination of the dihydroxybenzoyl moiety. Two portions of the obtained synthetic mixture, 200mg and 210mg, respectively, were separated by VCCC using two two-phase solvent systems that consisted of hexane–ethyl acetate–methanol–aqueous 0.2% trifluoroacetic acid (TFA) in the volume ratios of 8:2:5:5 and 7:3:5:5, respectively. These separations produced 35mg and 78mg of 3BrHBBA, respectively, each product of over 98% purity by HPLC at 254nm. 5BrHBBA was prepared by monobromination of the dihydroxybenzoyl moiety in the presence of glacial acetic acid. To separate the obtained synthetic mixture, VCCC was performed in the pH-zone-refining mode with a solvent system consisting of hexane–ethyl acetate–methanol–water (6:4:5:5, v/v) and with TFA used as the retainer acid and aqueous ammonia as the eluent base. Separation of a 1-g mixture under these conditions resulted in 142mg of 5BrHBBA of ∼99% purity by HPLC at 254nm. The isolated compounds were characterized by high-resolution mass spectrometry and proton nuclear magnetic resonance spectroscopy.

Preparative separation of 1,3,6-pyrenetrisulfonic acid trisodium salt from the color additive D&C Green No. 8 (pyranine) by pH-zone-refining counter-current chromatography

In developing analytical methods for batch certification of the color additive D&C Green No. 8 (G8), the U.S. Food and Drug Administration needed the trisodium salt of 1,3,6-pyrenetrisulfonic acid (P3S) for use as a reference material. Since P3S was not commercially available, preparative quantities of it were separated from portions of a sample of G8 that contained ∼3.5% P3S. The separations were performed by pH-zone-refining counter-current chromatography using dodecylamine (DA) as the hydrophobic counterion. The added DA enabled partitioning of the polysulfonated components into the organic stationary phase of the two-phase solvent system used, 1-butanol–water (1:1). Thus, a typical separation that involved 20.3 g of G8, using sulfuric acid as the retainer acid and 20% DA in the stationary phase and 0.1 M sodium hydroxide as the mobile phase, resulted in ∼0.58 g of P3S of greater than 99% purity. The identification and characterization of the separated P3S were performed by elemental analyses, proton nuclear magnetic resonance, high-resolution mass spectrometry, ultra-violet spectra, and high-performance liquid chromatography.

Ultra-Performance Liquid Chromatographic Determination of Manufacturing Intermediates and Subsidiary Colors in D&C Red No. 34 and Its Lakes

An ultra-performance liquid chromatography (UPLC) method was developed to determine the manufacturing intermediates and subsidiary colors in the monosulfo monoazo color additive D&C Red No. 34 and its lakes. This method is currently 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 UPLC method has replaced an HPLC method for determining the intermediates and a TLC method for determining the subsidiary colors. The intermediates are 2-amino-1-naphthalenesulfonic acid (Tobias acid) and 3-hydroxy-2-naphthalenecarboxylic acid (3-hydroxy-2-naphthoic acid). Subsidiary colors are positional isomers of the major dye component or related compounds containing lower numbers of substituent groups. The analytes are identified by comparison of their UPLC retention times and UV or visible absorption spectra with those of standards. Validation studies showed that peak area calibrations for the analytes were generally linear (R > 0.999), and recoveries were 98-103%. The LODs were 0.002-0.02%, and the RSDs at the specification levels were 0.7-2.2%. Survey analyses of 12 samples of certified D&C Red No. 34 straight colors and lakes from six domestic and foreign manufacturers yielded results for the intermediates by UPLC and HPLC that were consistent within experimental error. The UPLC analyses yielded results for the subsidiary colors that were consistently lower than results previously obtained by TLC, which we attribute to limitations of the TLC method. The new UPLC method provides sharper peaks, better peak separation, and faster analysis times than the formerly used HPLC method and is more accurate, much faster, and much less labor-intensive than the formerly used TLC method.