| Bisphenol A (BPA) is a kind of environment endocrine disturbance material. It is not only the primary raw material to produce polycarbonate resin and phenolic resin and other plastic, but also the stabilize reagent of polyvinyl chloride (PVC) and other high molecular material. Bisphenol A will dissolve from the food contacted substances when these plastic products are cleaned. The monomer can enter the body with the food and water, and also has teratogenicity mutagenicity and carcinogenicity to the biology. The problem of Bisphenol A dissolve from the high molecular plastic products has become the focus of world in recent years. Because of the migration from food contacted substances is a small amount, the concentration of Bisphneol A is hard to be detected. Thus, the method of enrichment must be developed. Consequently, building a method to determinate the migration of Bispheonl A which release from the high molecular food contacted substances has a significant sense.Methods:1. Chemometrics optimized-dispersive liquid liquid microextraction-fluorescence spectrophotometry:The optimal extraction condition was obtained by Plackett-Burman Design and Central Composite Face-Centered Design. The optimal determination condition was obtained by Full Factorial Design. Filled full the food contacted substances with different temperature water,3%acetic acid and10%ethanol. After12hours laying the substances aside, the samples were obtained. An appropriate mixture of chlorobenzene(extraction solvent) and acetone(dispersive solvent) was used for the extraction.Then determinating the fluoresence under the condition of λex=281nm, λem=311nm.2. Heated enrich-fluorescence spectrophotometry with ethanol enhanced sensitivity:Filled full the drinking bottles, one-off paper cups, one-off plastic cups with different temperature distilled water. After3hours laying the substances aside, the100mL samples were obtained. Put the samples on the electrical heated plate until the volume was less than5mL. The volume was fixed at10mL with distilled water. Then determinating the fluoresence under the condition of λex=281nm,λem=311nm.3. Soild phase extraction-fluorescence spectrophotometry with ethanol enhanced sensitivity:Different temperature distilled water was used for filled full the different packages of convenient noddle. After30min laying the substances aside, the50mL samples were obtained. After pass the solid phase extraction, the Bisphenol A was prepared by pH=10NaOH. Then the pH value of solvent was fixed at2-3by adding pH=1HCl. After drying the mixture solvent, the residual was dissloved by ethanol. Then determinating the fluoresence under the condition of λex=281nm,λem=311nm.Results:1.Chemometrics optimized-dispersive liquid liquid microextraction-fluorescence spectrophotometry:The optimal extraction conditions of5mL of water sample volume,40μL of extraction solvent (chlorobenzene),1mL of disperser solvent (acetone),1min of extraction time,6of pH value,3500rpm of centrifugation speed,5min of centrifugation time were obtained by central composite face-centered design (CCF). The optimal determination conditions of0.2mol/L HCL,2×10-4mol/L β-cyclodextrin were achieved by full factorial design. Under the optimum conditions, the calibration curve was linear in the range of1～50μg/L(R=0.999) in the water and10%ethanol. The limit of detection was0.53ug/L. The calibration graph was linear in the range of1～60μg/L(R=0.997) in the3%acetic acid. The limit of detection was0.85μg/L. The recovery ranged from95.4%to111.2%, while the relative standard deviation (RSD) was12.9%～15.1%(n=6). The bisphenol A has different migration amounts in boiling water,3%acetic acid and10%ethanol. The migration amount was lower than the detection limit in the condition of normal temperature water.2. Heated enrich-fluorescence spectrophotometry with ethanol enhanced sensitivity:The calibration curve was linear in the range of3～30μg/L. The related coefficient was0.997. The limit of detection was1.30μg/L. The recovery ranged from99.9%to107.8%, while the relative standard deviation (RSD) was2.9%～3.0%(n=6). The method was used for detected the migration amount of Bisphenol A from the drinking bottles, one-off paper cups, one-off plastic cups and so on plastic products. Only the Bisphenol A which released under the condition of boiling water from one-off paper cups was detected.3. Soild phase extraction-fluorescence spectrophotometry with ethanol enhanced sensitivity:The calibration curve was linear in the range of3～60μg/L. The related coefficient was0.997. The limit of detection was2.26μg/L. The recovery ranged from104.5%to108.0%, while the relative standard deviation (RSD) was3.2%～4.6%(n=6). The method was used for detected the migration amount of Bisphenol A from different packages of convenient noddle. The migration amount of Biphenol A was undetected.Conclusion:1.Chemometrics optimized-dispersive liquid liquid microextraction-fluorescence spectrophotometry: Compared to the traditional optimize method, chemometrics optimize method has the character of analysing interaction between the different factors. It also can reduce the time of experiment. The developed method was environmentally benign, rapid, simple and low cost for the determination of the migrate amount of bisphenol A. Accroding to the consequence of the study, the plastic bottles and bags should be used without the condition of boiling water, ethanol and acid.2. Heated enrich-fluorescence spectrophotometry with ethanol enhanced sensitivity:The developed method was environmentally benign, high sensitivity, simple and low cost for the determination of the migrate amount of bisphenol A. It was apporopriate for the migration amount of bisphenol A. Accroding to the consequence of the study, one-off paper cups should not be used with boiling water.3. Soild phase extraction-fluorescence spectrophotometry with ethanol enhanced sensitivity:The developed method was environmentally benign, high sensitivity, simple and low cost for the determination of the migrate amount of bisphenol A from food contacted substances. The material of solid phase extraction column was obtained easily. It was apporopriate for the migration amount of bisphenol A. Accroding to the consequence of the study, Bisphenol A would not release from packages of convenient noddle even if the condition of boiling water. |
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