| Bisphenol A is a phenolic compound, universally exist in the necessary plastic which people in contact with in the daily life. Bisphenol A has estrogen like activity, when it go into the human body, it can simulate and instead of endogenous hormone interact with the receptor in organism, affect the normal metabolism of the body, causing harm to human health. People exposed to bisphenol A generally has two kinds, one kind is inhalation or ingestion of bisphenol A in the environment; the other is the migration of bisphenol A in daily necessary plastic cause foodborne contact, so the detection of bisphenol A in food contact plastics is very necessary. There are many methods for detection of bisphenol A, the most common is the use of high performance liquid chromatography, the method is simple, fast, efficient and accurate.This thesis establishes a set of method of bisphenol A detected by HPLC-UV in food contact plastics. First of all, extract bisphenol A in the standard solution using solid phase extraction method, discussed the influence of the sample pH on the retention effect, select the leaching liquid which used to removal of impurities in the process, then determine the eluent type and dosage. Complete extraction and detection of bisphenol A in the optimal chromatographic conditions. The paper best solid-phase extraction and chromatography conditions as following:solid phase extraction column first activated with 6mL methanol,6mL ultra pure water to balance, the sample to solution,6mL ultra pure water washing, and finally use the 3mL 90% methanol water solution to elute the retention of bisphenol A in column. The mobile phase of the HPLC is:Vmethanoi.Vwater= 60:40, isocratic elution; flow control in 1mL/min; the column temperature is 30℃; auto injector, injection volume was 10μL; ultraviolet detector, the wavelength is 278nm. Under the optimum conditions, draw the standard curve of bisphenol A, the obtained regression equation is:Y=0.113X+0.0020 (R2=0.9999).Secondly, use of green solvent ionic liquid as the extractant, extraction of bisphenol A in standard solution, and then conduct experiments to discussed the main factors on extraction effect in the process. To determine the ionic liquid extraction conditions:use 1-octyl-3-methyl imidazole six fluoro phosphate 400μL, adjusting the sample pH=5.0, ultrasonic extraction 20min, static extraction after 15min, centrifugal operation for 6min, methanol fixed volume then sample analysis by HPLC. Under the optimum conditions, draw the standard curve of bisphenol A, the obtained regression equation is:Y=0.1181X-0.0106 (R2=0.9966). At last, compared the method of solid phase extraction and ionic liquid extraction method, the data and the chromatogram show that, under the best extraction conditions, the extraction efficiency of solid phase extraction is relatively high and more suitable for the extraction of bisphenol A in real samples.Finally, extract bisphenol A from samples of PVC plastic, PC samples and disposable paper cups by solid phase extraction, detection and analysis under optimum operating conditions. A display with bisphenol A exists in PVC samples, the content is 4.14mg/L, the average recovery of bisphenol A in PVC plastics is 89.97%-93.82%; All of the 5 PC plastic cup samples were detected with small migration amounts of bisphenol A, respectively 1.1956mg/L,1.9177mg/L,1.5195mg/L,1.7442mg/L and 0.8965mg/L, the average recovery of bisphenol A in PC plastic containers is 91.08%-94.66%; In the detection of disposable paper cup we found that, there are 2 paper cups detected the amount of migration of bisphenol A, respectively 4.1 lmg/mL, 4.63mg/mL, the average recovery of bisphenol A in disposable water cup is 89.76%～ 92.98%. Summary of experimental data, found the same category products of different brands, bisphenol A detection results are not the same, commercially available products may have very big difference in the quality of bisphenol A, so we should pay attention to the impact on human health. |
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