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An analytical method using GC/MS was developed for bisphenol A (BPA) in foods and BPA was determined in canned foods and fresh foods such as vegetables, fruit and meat. BPA was extracted with acetone from the samples and the extract was concentrated at under 40̮ in vacuo to afford an aqueous solution, which was washed with hexane after alkalization and extracted with 50̮ diethyl etherῌhexane after acidification. Extracts were cleaned up on a PSA and/or a C 18 cartridge column, and BPA was derivatized with heptafluorobutyric anhydride and determined by GC/MS (SIM). This method was applicable to the detection and determination of BPA residues in food samples at the level of 1 ng/g. Among canned foods, BPA was found in 6 corned beef, 1 chicken, 9 sweet corn and 3 bean samples at the levels of 17ῑ602 ng/g, 212 ng/g, 2.3ῑ75 ng/g and 3.5ῑ26 ng/g, respectively. BPA was also detected in 1 retort soup and 1 retort pack product at the levels of 11 ng/g and 86 ng/g, respectively. As for dairy products, BPA was not detected in butter and milk. Among fresh foods, BPA was detected in 2 fish and 3 liver samples at the levels of trace (tr)ῑ6.2 ng/g and trῑ2.2 ng/g, respectively. In vegetables, fruits and chocolates, a trace level of BPA was detected in only 1 chocolate. Traces of BPA were also detected in 3 samples of 6 boxed lunches.

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An analytical method was developed for determination of residual avoparcin in chicken muscle by measuring a-and b-avoparcin, major components of the pharmaceutical preparation avoparcin, using HPLC with UV and amperometric detectors. The analytical HPLC was run on a Cosmosil 5C18-AR column (4.6 mm25 cm) with a gradient formed from A: 2.5 acetic acid, 0.01 mol/L sodium heptane sulfonic acidῌacetonitrile (88.5 : 11.5) (pH 4.0) and B: 2.5 acetic acidῌ acetonitrile (10 : 90), using UV and amperometric detection (AMD) with glassy-carbon electrode (ΐ 900 mV). Avoparcin was extracted from chicken muscle by homogenization with methanolῌ0.2 mol/L sulfuric acid (6 : 4) followed by centrifugation after pH adjustment to 4 with 1 mol/L sodium hydroxide. The supernatant was evaporated to dryness, and the residue was dissolved in water. The aqueous layer was adjusted to pH 4 by adding 1 mol/L sodium hydroxide. Then it was purified on a Sep-Pak tC18 plus ENV cartridge. The cartridge was washed with water, and retained substances were eluted with 50 methanol. The eluate was evaporated to dryness under reduced pressure. The residue was dissolved in water and determined by HPLC. Recoveries of avoparcin spiked in chicken muscle were 73.1ῐ88.1 at levels of 2ῐ10 mg/g. The detection limits were 0.5 mg/g (UV) and 0.2 mg/g (AMD). ῌ QῘQῠῦQῸ 60 ̯ 10 QῲQ`Q̱̮̳ῦ ῤQ̮῝Ὺ̯ 6), 7) ῍ ῩQΰῢQQQQῗQ 5) ῠQ`῝Ὺ̯ Ῑ̯Ῐῌ ̯ῥQῌ ῐQQῥQQ̰ῒῘ̮̰ῡ῞̯ῨQ 9Q῞ῌ ̯ῥQ`ΎQQ῞̯῍ ῞ῗ῞ῌ ῨQ 10 ̯ῡ 11 ̯

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