食品包装聚碳酸酯成型品双酚A检测及迁移特性研究

目的:建立食品包装材料聚碳酸酯(PC)成型品双酚A含量检测方法,探讨双酚A在不同模拟浸出液中的迁移特性。方法:采用高效液相色谱-荧光检测法(HPLC-FD),Alltima C18柱(150×4.6mm,5μm)分离,流动相为乙腈和水(58∶42,V/V),流速1.0mL/min,柱温40℃,荧光激发波长275nm,发射波长310nm。PC成型品按2mL/cm2分别用水、20%和65%乙醇(V/V)在90℃浸泡6h。结果:双酚A在0.02～4μg/mL范围内具有良好的线性关系(r=0.999),检测限为10ng/mL,方法回收率为91%～108%,相对标准偏差(RSD)小于6%(n=5)。两种典型的PC成型品中双酚A含量分别为17.14mg/kg和46.69mg/kg,在水、20%和65%乙醇中的迁移量分别为0.782～1.11、0.734～0.684、1.84～2.49mg/kg。结论:该方法快速简便,准确度高,适用于PC成型品中双酚A的检测。实验条件下PC中有微量双酚A溶出,且溶出量与PC材质有关。     

加热方式对聚碳酸酯中双酚A迁移规律影响

结合聚碳酸酯(PC)塑料的实际使用情况,以蒸馏水、自来水和矿泉水为食品模拟物,采用高效液相-荧光检测法测定PC塑料中双酚A在微波加热和恒温加热时向不同水质中的迁移量。结果表明:微波加热和恒温加热条件下,迁移率均随加热时间的延长而增加,其中蒸馏水中迁移率最低。微波加热比常规恒温加热达到平衡的时间缩短近12倍,说明微波加热能加速塑料中有害物质的迁移速率;蒸馏水和自来水在2种加热方式下的最大迁移率并无差别(P>0.05),矿泉水在微波加热时最大迁移率要高于恒温加热(P<0.01),因此,使用微波加热食品时,应注意容器所盛装食品的性质和控制加热的时间,以免引起PC容器中双酚A向食品的迁移。     

Alkylphenol and bisphenol A levels in rubber products

Levels of p-t-butylphenol (PTBP), p-t-octylphenol (PTOP), p-nonylphenol (NP) and bisphenol A (BPA) in rubber products in food-contact use, infant-related use and other uses are reported. Of 60 rubber products tested, PTOP was found in three in a concentration range of 2.2-37 μg g^-1, and NP in 15 in a concentration range of 2.6-513 μg g^-1. PTBP and BPA were not found in any sample. PTOP and NP were not detected in any infant-related sample, regardless of the material type. In contrast, among the samples with food contact and with other uses, the percentages containing PTOP or NP were 33 and 43%, respectively. A migration test was performed on eight samples containing NP and used in food-contact environments. The migration level of NP from spatulas to n-heptane was 0.83-1.52 μg ml^-1. The average migration rates to water, 20% ethanol and n-heptane were 0.03, 0.7 and 6.6%, respectively.     

聚碳酸酯新料和回收料中双酚A含量及迁移规律分析

目的对比分析聚碳酸酯(polycarbonate,PC)新料和回收料中双酚A(bisphenol A,BPA)含量并研究其在食品模拟液中的迁移规律。方法利用高效液相色谱仪配荧光检测器对比研究PC新料与回收料中BPA的含量及迁移量。利用凝胶渗透色谱仪(gel permeation chromatography,GPC)测量PC分子量,分析分子量对BPA迁移的影响。结果多次熔融挤出加工后PC粒料的分子量逐步降低,分子量分布(Mw/Mn)变宽,回收料经过多次熔融挤出后分子链断裂加剧,大分子降解增加,因此释放出更多的游离BPA。BPA在95%酒精溶液中迁移量远大于10%酒精及水。温度对迁移性影响很大,相同迁移时间下60℃的迁移量比25℃高10倍左右。PC回收料的游离BPA含量及迁移量大于新料。结论 PC回收料用于食品接触材料可能会造成更多的BPA的迁移。     

Effect of amines in the release of bisphenol A from polycarbonate baby bottles

The key block for the production of polycarbonate (PC) is bisphenol A (BPA). Recent studies have proven that this monomer is able to migrate from PC baby bottles into food simulants and, although this is a polemical subject, numerous investigations indicate that BPA may have an effect on the human health. For these reasons, BPA safety regarding human exposure has recently become an alarming issue.Amines are a class of chemicals which are present in foodstuffs, such as milk. For this reason PC baby bottles, while being used, are continuously in contact with several amines, some of which are able to cause PC aminolysis, resulting in the release of BPA.In this work, 16 substances (14 with amine groups and 2 with amide groups) were tested in order to verify if they were able to increase BPA release by increasing PC depolymerization. High-performance liquid chromatography (HPLC) with fluorescence detection (FLD) and gas chromatography coupled to mass spectrometry (GC–MS) were used to quantify and identify the BPA, respectively. Although most of the substances tested did not increase the release of BPA from PC, some of them had a significant effect and high levels of this monomer were measured in the solutions. Of all of the amines tested that originating the worst case of BPA release was 1,4-diaminobutane. Also known as putrescine, 1,4-diaminobutane is a biogenic amine that results from protein degradation and it may be present in milk. In this case, BPA concentration in the solution was more than 5000 times the level found in the control sample.     

Effect of detergents in the release of bisphenol A from polycarbonate baby bottles

Bisphenol A (BPA) is a monomer crucial for the production of polycarbonate (PC). Recently, it has been verified that BPA is able to migrate from PC baby bottles into food simulants and numerous studies indicate that BPA may affect human health.In this work, five different detergents and bleach were tested to verify if they were able increasing the BPA release from the PC. High performance liquid chromatography (HPLC) with fluorescence detection (FLD) and gas chromatography coupled to mass spectrometry (GC–MS) were used to quantify and identify BPA. Of all detergents tested, only with one was not detected a BPA concentration higher than the control. In the worst case, BPA levels detected were about 500 times higher than the control and the concentration kept high even after rinsing the PC samples three times. In the case of bleach, while it was in contact with the PC, the BPA released was not detected.     

An analysis method for determining residual hexane in health functional food products using static headspace gas chromatography

A method for analyzing the contents of residual hexane in health functional food products was developed. The dissolving solvents in the health functional food products and the internal standard selected were N,N-dimethylacetamide and heptane, respectively. The analysis conditions for headspace-gas chromatography/flame ionization detection (HS-GC/FID) and headspace-gas chromatography/mass spectrometry (HS-GC/MS) were determined as 18 mL of headspace volume, 100°C of headspace oven temperature, and 30 min of equilibration time; a Durabond (DB)-624 column was selected for this analysis. To validate this method, which applies N,N-dimethylacetamide as a dissolving solvent, the limit of detection and limit of quantification (LOQ) values based on the HS-GC/FID and HS-GC/MS analyses results were found to be 0.10, 0.29 and 0.16, 0.47 mg/L, respectively. The recoveries and coefficient of variation (CV) obtained by HS-GC/MS were 96.39–119.86% and 0.04–1.25%, respectively, better than those obtained by HS-GC/FID. By applying the HS-GC/MS method, it was possible to analyze the content of the residual hexane in 60 different types of health functional food products.     

Migration of bisphenol A from polycarbonate baby bottles under real use conditions

Migration of the potential endocrine disrupter, bisphenol A (BPA), from 31 polycarbonate (PC) baby bottles into aqueous food simulants was studied under real repetitive use, using a sensitive and fully validated liquid chromatographic method with fluorescence detection. Confirmation of the presence of BPA was performed by liquid chromatography-mass spectrometry (LC-MS). The effects of cleaning in a dishwasher or with a brush, sterilization with boiling water and the temperature of migration were examined. It was shown that temperature was the crucial factor for the migration of BPA from the plastic bottles to water. All samples released BPA in the concentration range 2.4-14.3 µg kg^-1 when filled with boiled water and left at ambient temperature for 45 min. The decrease of BPA release in the sterilization water and in the food simulant over 12 cycles of use indicated that the hypothesis of polymer degradation in water is dubious. Estimated infantile dietary exposure, regarding the use of PC baby bottles, ranged between 0.2 and 2.2 µg kg^-1 bw day^-1, which is below the Tolerable Daily Intake of 50 µg kg^-1 bw recently established by EFSA.     

Migration of bisphenol A from polycarbonate baby bottles under real use conditions

Migration of the potential endocrine disrupter, bisphenol A (BPA), from 31 polycarbonate (PC) baby bottles into aqueous food simulants was studied under real repetitive use, using a sensitive and fully validated liquid chromatographic method with fluorescence detection. Confirmation of the presence of BPA was performed by liquid chromatography–mass spectrometry (LC–MS). The effects of cleaning in a dishwasher or with a brush, sterilization with boiling water and the temperature of migration were examined. It was shown that temperature was the crucial factor for the migration of BPA from the plastic bottles to water. All samples released BPA in the concentration range 2.4–14.3 µg kg^?1 when filled with boiled water and left at ambient temperature for 45 min. The decrease of BPA release in the sterilization water and in the food simulant over 12 cycles of use indicated that the hypothesis of polymer degradation in water is dubious. Estimated infantile dietary exposure, regarding the use of PC baby bottles, ranged between 0.2 and 2.2 µg kg^?1 bw day^?1, which is below the Tolerable Daily Intake of 50 µg kg^?1 bw recently established by EFSA.     

反射法测定芦荟制品中乳酸的含量

芦荟制品中乳酸的含量反映芦荟制品加工过程中微生物控制情况,也反映芦荟制品品质的变化情况。本文建立了一种反射计量测定乳酸含量的新方法。实验结果表明,该方法快速灵敏、操作简单、重复性好,可用于芦荟制品生产过程中乳酸含量的测定及其产品质量的评价。      

Survey of bisphenol A in bottled water products in Canada

A method based on isotope dilution headspace solid-phase microextraction and gas chromatography/mass spectrometry was used to assess levels of bisphenol A (BPA) in 56 samples of bottled water products sold in Canada. Levels of BPA in samples of all 51 non-polycarbonate (PC) bottled water products were lower than the method detection limit (0.50 µg l^–1). Levels of BPA in most bottled water products in PC carboys were low, ranging from <0.50 to 1.4 µg l^–1 with an average of 0.75 µg l^–1. However, BPA was detected at levels of 8.8 and 6.5 µg l^–1 in two bottles of the bottled water products in PC carboys from the same product analysed over a 5-week period, likely due to accidental or careless exposure of the products to heat (e.g. under the sun) during storage and/or transportation for extended periods of time.     

Migration of bisphenol A into water from polycarbonate baby bottles during microwave heating

A comprehensive migration database was established for bisphenol A from polycarbonate baby bottles into water during exposure to microwave heating. Eighteen different brands of polycarbonate baby bottles sold in Europe were collected. Initial residual content of bisphenol A and migration after microwave heating were determined. Residual content of bisphenol A in the polycarbonate baby bottles ranged from 1.4 to 35.3 mg kg^?1. Migration of bisphenol A was determined by placing a polycarbonate bottle filled with water in a microwave oven and heating to 100°C; the level of bisphenol A in the water was analysed by GC–MS. The procedure of microwave heating and analysis was repeated twice for the same bottle and, thus, three migration extracts were prepared for each test specimen. Migration of bisphenol A into water ranged from <0.1 to 0.7 µg l^?1. There was no correlation between the amount of residual content of bisphenol A in the bottles and the migration of bisphenol A into water. Furthermore, there was no correlation between the amounts of bisphenol A in consecutive migration extracts. Data show that during three microwave-heating cycles of a baby bottle made from polycarbonate, microwave radiation had no effect on the migration of bisphenol A into water from polycarbonate. All levels found were well below the specific migration limit of 0.6 mg kg^?1 specified for bisphenol A in Commission Directive 2004/19/EC.     

Migration of bisphenol A into water from polycarbonate baby bottles during microwave heating

A comprehensive migration database was established for bisphenol A from polycarbonate baby bottles into water during exposure to microwave heating. Eighteen different brands of polycarbonate baby bottles sold in Europe were collected. Initial residual content of bisphenol A and migration after microwave heating were determined. Residual content of bisphenol A in the polycarbonate baby bottles ranged from 1.4 to 35.3 mg kg(-1). Migration of bisphenol A was determined by placing a polycarbonate bottle filled with water in a microwave oven and heating to 100 degrees C; the level of bisphenol A in the water was analysed by GC-MS. The procedure of microwave heating and analysis was repeated twice for the same bottle and, thus, three migration extracts were prepared for each test specimen. Migration of bisphenol A into water ranged from <0.1 to 0.7 microg l(-1). There was no correlation between the amount of residual content of bisphenol A in the bottles and the migration of bisphenol A into water. Furthermore, there was no correlation between the amounts of bisphenol A in consecutive migration extracts. Data show that during three microwave-heating cycles of a baby bottle made from polycarbonate, microwave radiation had no effect on the migration of bisphenol A into water from polycarbonate. All levels found were well below the specific migration limit of 0.6 mg kg(-1) specified for bisphenol A in Commission Directive 2004/19/EC.     

高效液相色谱-质谱法测定聚碳酸酯水杯中双酚A迁移量

目的 建立高效液相色谱-质谱法(high performance liquid chromatography-mass spectrometry, HPLC-MS)测定聚碳酸酯(polycarbonate, PC)水杯中双酚A迁移量的方法。方法 选用水、4%乙酸溶液、10%乙醇和异辛烷溶液作为食品模拟液, 准确量取迁移试验中得到的食品模拟液1 mL, 通过0.22 μm微孔滤膜后, 用高效液相色谱-质谱联用仪对双酚A进行分离测定。结果 该方法相对标准偏差不大于3.24%(n=6), 回收率在87.7%~105.0%之间; 检出限为 1 μg/L。结论 该方法样品前处理方法简便, 检出限高, 操作简单, 线性关系好, 适合于PC水杯及不同塑料制品中迁移双酚A的检测分析。     

发酵液中酮基还原酶活性测定方法的构建

本研究以4-氯乙酰乙酸乙酯（COBE）为底物,还原型辅酶Ⅱ （NADPH）为辅酶,应用紫外-可见光分光光度计法测定发酵液中酮基还原酶活性,通过连续测定NADPH消耗量来计算酶活力,得到了最佳反应体系：NADPH浓度为0.2 mmol/L,COBE浓度为1.0 mmol/L,磷酸缓冲溶液浓度为100 mmol/L、pH值为6,反应温度为40℃.在此条件下平行检测5次酶活,相对标准偏差（RSD）为0.48％.此方法操作简便,耗时短,精确度高,重复性好,可作为发酵液中酮基还原酶活性测定方法加以推广.     

Migration of bisphenol A into water from polycarbonate baby bottles during microwave heating.

A comprehensive migration database was established for bisphenol A from polycarbonate baby bottles into water during exposure to microwave heating. Eighteen different brands of polycarbonate baby bottles sold in Europe were collected. Initial residual content of bisphenol A and migration after microwave heating were determined. Residual content of bisphenol A in the polycarbonate baby bottles ranged from 1.4 to 35.3 mg kg(-1). Migration of bisphenol A was determined by placing a polycarbonate bottle filled with water in a microwave oven and heating to 100 degrees C; the level of bisphenol A in the water was analysed by GC-MS. The procedure of microwave heating and analysis was repeated twice for the same bottle and, thus, three migration extracts were prepared for each test specimen. Migration of bisphenol A into water ranged from <0.1 to 0.7 microg l(-1). There was no correlation between the amount of residual content of bisphenol A in the bottles and the migration of bisphenol A into water. Furthermore, there was no correlation between the amounts of bisphenol A in consecutive migration extracts. Data show that during three microwave-heating cycles of a baby bottle made from polycarbonate, microwave radiation had no effect on the migration of bisphenol A into water from polycarbonate. All levels found were well below the specific migration limit of 0.6 mg kg(-1) specified for bisphenol A in Commission Directive 2004/19/EC.