The analytical capability of the high speed countercurrent chromatograph model 4000 (HSCCC-4000) has been improved by optimizing the dimensions of the multilayer coiled column. Using a two-phase solvent system of n-hexane-ethyl acetate - methanol - water (1:1:1:1) and a set of indole auxins as test samples, a series of studies was conducted to evaluate performance of coiled columns with i.d.s ranging from 0.1 to 0.55 mm. The studies on the stationary phase retention indicated that multilayer coils of 0.55 mm and 0.30 mm i.d. provide satisfactory retention of the stationary phase while the 0.10 mm i.d. column fails to yield reproducible retention. The best partition efficiencies were obtained from the 0.30 mm i.d. multilayer coil with a 6 ml capacity which produced theoretical plate numbers ranging from 5500 to 10500 with a resolution factor of 2.30. The feasibility of interfacing the HSCCC-4000 with a mass spectrometer is briefly discussed.

High-speed counter-current chromatography (HSCCC) has been successfully applied to the separation of the components of Food Color Red No. 106 (R-106). The separation was performed using 25 mg of the sample with a two-phase solvent system composed of n-butanol and 0.01 M trifluoroacetic acid (1:1, v/v). Analyses by thin-layer chromatography, high-performance liquid chromatography and fast atom bombardment mass spectrometry confirmed that HSCCC was effective in the purification of the components of R-106. The separation gave 21 mg of a 99.9% pure main component (Acid Red) and 0.9 mg of 98.0% pure subsidiary dye which is probably a des-ethyl derivative.

A simple, rapid and reliable method for the determination of residual sulphonamide antibacterials (SAs) (sulphathiazole, sulphisozole, sulphamethoxazole, sulphadiazine, sulphamerazine, sulphadimidine, sulphamonomethoxine, sulphadimethoxine, sulphamethoxypyridazine and sulphaquinoxaline) in meat, fish and egg was developed using a combination of high-performance liquid chromatography (HPLC) and clean-up with an amino-type prepacked cartridge. SAs were extracted with ethyl acetate and applied to a Baker 10 amino cartridge. After elution from the cartridge, SAs were determined by HPLC. The recoveries at the level of 0.5 ppm were 73.7-99.1% and the detection limits were 0.05 ppm. The analysis time per sample was about 45 min.

Performance of two countercurrent chromatographic models, high speed countercurrent chromatograph (HSCCC-4000) and analytical toroidal coil centrifuge (TCC), is evaluated in terms of theoretical plate number, resolution factor and separation time to assess their analytical capability. A series of experiments was conducted to investigate the effects of internal diameter and length of the coiled column, and flow rate of the mobile phase on the separation of indole auxins in two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water at different volume ratios. The three components of indole auxins were completely resolved in 16 min with a HSCCC system equipped with a multilayer coil of a 0.55 mm I.D. PTFE tube with theoretical plates ranging from 1290 to 829. Similar separation was achieved in 24 min with a TCC systems equipped with a 0.3 mm I.D. PTFE tube with theoretical plates ranging from 1811 to 969. It is concluded that both systems have comparable analytical capability at the present stage of development.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotodecomposition products of tetracycline in aqueous solutionHisao Oka, Yoshitomo Ikai, Norihisa Kawamura, Masuo Yamada, Kenichi Harada, Shinobu Ito, and Makoto SuzukiCite this: J. Agric. Food Chem. 1989, 37, 1, 226–231Publication Date (Print):January 1, 1989Publication History Published online1 May 2002Published inissue 1 January 1989https://pubs.acs.org/doi/10.1021/jf00085a052https://doi.org/10.1021/jf00085a052research-articleACS PublicationsRequest reuse permissionsArticle Views637Altmetric-Citations87LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

A simple and rapid method for the determination of residual pyridonecarboxylic acid antibacterials (PCAs) (oxolinic acid, nalidixic acid and piromidic acid) in fish was developed using a combination of high-performance liquid chromatography (HPLC) and clean-up with an amino-type prepacked cartridge. PCAs were extracted with n-hexane-ethyl acetate (1:3) and the extract was applied to a Baker 10 amino cartridge. PCAs were eluted from the cartridge with acetonitrile-methanol-0.01 M aqueous oxalic acid solution (pH 3.0) (3:1:6) and were determined by HPLC. The separations were performed on Nucleosil 3C18 (3 microns, 75 x 4.6 mm I.D.) using a mobile phase containing oxalic acid. The recoveries of PCAs from various fishes fortified at the level of 1.0 ppm were 77.1-95.5%, and the detection limits were 0.05 ppm. The analytical time per sample was less than 30 min.

Isocratic high-performance liquid chromatographic (HPLC) systems were established for analytical and preparative separation of the components of the antibiotic preparation bacitracin (BC). The best analytical results were obtained using a C18 modified silica gel column (Capcell Pak C18) with a solvent system of 0.04 M disodium hydrogenphosphate buffer and methanol (4:6), pH 9–10. The calibration graphs showed good linear relationships between 50 and 1000 ng for BC-A and between 65 and 1000 ng for BC-F. With respect to the preparative HPLC, a Capcell Pak C18 column with methanol-0.05 M aqueous sodium sulphate solution (6:4) as a mobile phase gave satisfactory results. The isolation of BC-A and -F was readily achieved without decomposition of the components by using the present preparative HPLC followed by desalting on a prepacked C18 cartridge.

Organic Mass SpectrometryVolume 24, Issue 1 p. 74-75 Oms Letter Identification of food dyes by TLC/SIMS with a condensation technique Katsuyoshi Masuda, Corresponding Author Katsuyoshi Masuda Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanFaculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanSearch for more papers by this authorKen-Ichi Harada, Corresponding Author Ken-Ichi Harada Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanFaculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanSearch for more papers by this authorMakoto Suzuki, Corresponding Author Makoto Suzuki Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanFaculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanSearch for more papers by this authorHisao Oka, Hisao Oka Aichi Prefectural Institute of Public Health, Tsuji-machi, Kita-ku, Nagoya 462, JapanSearch for more papers by this authorNorihisa Kawamura, Norihisa Kawamura Aichi Prefectural Institute of Public Health, Tsuji-machi, Kita-ku, Nagoya 462, JapanSearch for more papers by this authorMasuo Yamada, Masuo Yamada Aichi Prefectural Institute of Public Health, Tsuji-machi, Kita-ku, Nagoya 462, JapanSearch for more papers by this author Katsuyoshi Masuda, Corresponding Author Katsuyoshi Masuda Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanFaculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanSearch for more papers by this authorKen-Ichi Harada, Corresponding Author Ken-Ichi Harada Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanFaculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanSearch for more papers by this authorMakoto Suzuki, Corresponding Author Makoto Suzuki Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanFaculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, JapanSearch for more papers by this authorHisao Oka, Hisao Oka Aichi Prefectural Institute of Public Health, Tsuji-machi, Kita-ku, Nagoya 462, JapanSearch for more papers by this authorNorihisa Kawamura, Norihisa Kawamura Aichi Prefectural Institute of Public Health, Tsuji-machi, Kita-ku, Nagoya 462, JapanSearch for more papers by this authorMasuo Yamada, Masuo Yamada Aichi Prefectural Institute of Public Health, Tsuji-machi, Kita-ku, Nagoya 462, JapanSearch for more papers by this author First published: January 1989 https://doi.org/10.1002/oms.1210240116Citations: 18AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. References 1 J. S. Steele, J. Assoc. Off. Anal. Chem. 67, 540 (1984). 2 R. A. Hoodless, K. G. Pitman, T. E. Stewart, J. Thomson and J. E. Arnold, J. Chromatogr. 54, 393 (1971). 3 H. Oka, Y. Ikai, N. Kawamura, Mi. Yamada, H. Inoue, T. Ohno, K. Inagaki, A. Kuno and N. Yamamoto, J. Chromatogr. 411, 437 (1987). 4 K. Tsunoda, N. Inoue, H. Ito and A. Hasebe, J. Food Hyg. Soc. Jpn. 27, 296 (1986). 5 Y. Kushi and S. Handa, J. Biochem. 98, 265 (1985). 6(a) Y. Nakagawa, Annu. Rep. Shionogi Res. Lab. 35, 1 (1985). (b) K. Iwatani, T. Kadono and Y. Nakagawa, Mass Spectrosc. 34, 181 (1986). 7 K. Iwatani and Y. Nakagawa, Mass Spectrosc. 34, 189 (1986). 8 G. C. DiDonato and K. L. Busch, Anal. Chem. 58, 3231 (1986). 9 H. Iwabuchi, H. Nagashima and K.-I. Nakamura, Mass Spectrosc 35, 349 (1987). 10 M. S. Stanley and K. L. Busch, Anal. Chem. Acta 194, 199 (1987). 11 H. Iwabuchi, A. Kanagawa and K.-I. Nakamura, J. Chromatogr. 414, 139 (1987). 12 J. L. Witten, M. H. Schaffer, M. O'Shea, J. C. Cook and K. L. Rinehart, Biochem. Biophys. Res. Commun. 124, 350 (1984). 13 K. Masuda, K.-I. Harada, M. Suzuki, H. Oka, N. Kawamura and M. Yamada, Org. Mass Spectrom., in preparation. 14 E. Stahl, ‘Thin-Layer Chromatography’, 2nd edn, Springer-Verlag, Berlin, p. 411, 1969. Citing Literature Volume24, Issue1January 1989Pages 74-75 ReferencesRelatedInformation

A technique for the simultaneous determination of sorbic acid, benzoic acid, dehydroacetic acid, p-hydroxybenzoic acid esters (ethyl, isopropyl, n-propyl, isobutyl and n-butyl p-hydroxybenzoate) and saccharin sodium using ion-pair reversed-phase high-performance liquid chromatography is described. The nine food additives were separated on a Nucleosil 3C18 (3 microns) column (75 x 4.6 mm I.D.) using methanol-acetonitrile-0.05 M aqueous acetonic acid solution (pH 4.5) (1.5:1:3.1) containing 2.5 mM cetyltrimethylammonium chloride as the mobile phase at a flow-rate of 1.0 ml/min, and detected at 233 nm. The food additives were separated within 18 min and their calibration graphs were linear between 2 and 200 ng.

A simultaneous analytical system for residual tetracycline antibiotics (TCs) in animal tissues including liver has been developed. This system consists of three methods using Baker 10 C18 clean-up followed by high-performance liquid chromatography (method A), thin-layer chromatography (TLC)—UV densitometry (method B) and TLC with spray reagents (method C). Methods A and B were established for the precise determination of TCs and method C for universal screening. The recoveries from beef liver fortified at the level of 1.0 ppm and their coefficients of variation were 60.5–83.3% and 2.3–3.9% (method A) and 58.1–92.8% and 1.0–3.7% (method B), respectively. The detection limits in animal tissues were 0.01 ppm (method A) and 0.1 ppm (methods B and C). The time required for the analysis of four samples was 2.5–3 h with each method.

Analytical methods for eight tetracyclines (TCs) were established using silica gel high-performance thin-layer chromatography (HPTLC), reversed-phase thin-layer chromatography (RP-TLC) and high-performance liquid chromatography (HPLC). Good separations of eight TCs were obtained using chloroform-methanol-5% disodium ethylenediaminetetraacetate solution (65:20:5) (lower layer) and methanol acetonitrile 0.5 M oxalic acid solution (1:1:4) (pH 3.0) on silica gel HPTLC and C8 TLC plates, respectively. A combination of HPTLC and RP-TLC made possible the identification of the eight TCs. Each calibration graph was linear between 0.1 and 1.0 microgram using UV densitometry except for rolitetracycline. For detection reagents, the diazonium salts including Fast Violet B gave variously coloured spots with the eight TCs and good sensitivities were obtained except with minocycline. In HPLC, the simultaneous analysis of the eight TCs on a C8 column was possible using methanol-acetonitrile-0.01 M oxalic acid solution (1:1.5:7) adjusted to pH 3.0 as the mobile phase. A linear relationship was obtained between 1.0 and 10 ng using the usual sample preparation except for rolitetracycline. The direct determination of rolitetracycline was possible using tetrahydrofuran, dimethyl sulphoxide and the mobile phase as solvents for preparation of the sample. For the determination of residual rolitetracycline, it was effective to measure the amount of rolitetracycline as tetracycline by HPLC, HPTLC and RP-TLC after conversion of rolitetracycline to tetracycline by incubating for 5 min in methanol at 50 degrees C.

A technique for the determination of food dyes using reversed-phase thin-layer chromatography on octadecyl-modified silica is described. A solvent system containing 5.0% aqueous sodium sulphate solution enables good separation of the food dyes. Their separation is dependent on the pH of the solvent system, good separation among all dyes being obtained between pH 6.0 and 7.0. The determination of thirteen dyes can be achieved by a combination of methanol-acetonitrile-5.0% aqueous sodium sulphate solution (3:3:10) (solvent system A) and methanol-methyl ethyl ketone-5.0% aqueous sodium sulphate solution (1:1:1) (solvent system B). Solvent system A was used for the determination of Tartrazine, Amaranth, Indigo Carmine, New Coccine, Sunset Yellow FCF, Allura Red AC, Fast Green FCF and Brilliant Blue FCF and for the screening of Acid Red (R-106), Eosin (R-103), Erythrosin (R-3), Rose Bengale (R-105) and Phloxine (R-104). When the spots of R-3, R-103, R-104, R-105 and R-106 appear on the plate, their determination can be achieved by using solvent system B. Each calibration graph was linear between 0.2 and 1.0 micrograms.