食品包装材料中双酚A在食品模拟物中迁移规律的研究

食品塑料包装材料的安全是保障食品安全的重要一环,包装材料中的双酚A潜在迁移性对人体健康的危害已引起社会的关注. 分别选取蒸馏水、3%乙酸(体积分数)和10%乙醇(体积分数)3种食品模拟物,浸泡已知双酚A含量的食品包装材料,在一定的时间点测试浸泡液中双酚A含量,研究迁移量与模拟物之间的关系. 结果表明,在不同食品模拟物下包装材料中双酚A的迁移量不同,其特定迁移量顺序为10%乙醇溶液>3 %乙酸溶液>蒸馏水. 并研究了温度、时间及微波作用影响食品包装材料中双酚A向食品中的迁移量,结果表明,双酚A向食品中迁移量随接触时间的延长、温度的升高而增加,微波作用能显著提高包装材料中双酚A向食品中的迁移量.     

Highly sensitive inhibitory kinetics fluorescence method for determination of arsenic

A new and highly sensitive inhibitory kinetic fluorescence method for the determination of arsenic (III) has been established based on its inhibitory effect on the oxidation reaction of Acridine red (ADR) by KBrO₃ in sulphuric acid medium. The reaction has been followed by measuring the enhancement of fluorescence at 550?nm. It relies on the linear relationship where the change in the fluorescence (ΔF) versus added As(III) amounts in the range of 0–0.450?µg?mL^?1 is plotted, under the optimum conditions. The sensitivity of the proposed method, i.e. the limit of detection, is 2.1?×?10^?2?ng?mL^?1. The method is featured with good accuracy and reproducibility for arsenic (III) determination. This method was successfully applied for the quantitative determination of arsenic (III) in food products samples, and the relative standard deviations and the recoveries were in ranges of 2.31–2.83% and 90.0–107.2%, respectively. A review of recently published catalytic or inhibiting kinetic methods for the determination of arsenic (III) has also been presented for comparison. The mechanism of reaction was studied.     

表面活性剂流动相用于混合固定相薄层色谱

将表面活性剂流动相用于ＧＤＸ与硅胶Ｇ混合固定相薄层色谱,用表面活性剂、乙醇和水的混合流动相对一些水溶性食品染料及指示剂等进行了分离,得到满意的结果,可以部分代替非极性键合相薄板。     

Autonomously Propelled Motors for Value‐Added Product Synthesis and Purification

A proof‐of‐concept design for autonomous, self‐propelling motors towards value‐added product synthesis and separation is presented. The hybrid motor design consists of two distinct functional blocks. The first, a sodium borohydride (NaBH₄) granule, serves both as a reaction prerequisite for the reduction of vanillin and also as a localized solid‐state fuel in the reaction mixture. The second capping functional block consisting of a graphene–polymer composite serves as a hydrophobic matrix to attract the reaction product vanillyl alcohol (VA), resulting in facile separation of this edible value‐added product. These autonomously propelled motors were fabricated at a length scale down to 400 μm, and once introduced in the reaction environment showed rapid bubble‐propulsion followed by high‐purity separation of the reaction product (VA) by the virtue of the graphene–polymer cap acting as a mesoporous sponge. The concept has excellent potential towards the synthesis/isolation of industrially important compounds, affinity‐based product separation, pollutant remediation (such as heavy metal chelation/adsorption), as well as localized fuel‐gradients as an alternative to external fuel dependency.     

液相色谱串联质谱法(LC-MS/MS)分析宠物食品中三聚氰胺

三聚氰胺(melamine)为白色或无色结晶,通常用于塑料制品中合成树脂的生产中,高温和酸性条件下能引起三聚氰胺转移到食品中.三嗪类农药环丙氨嗪(cyromazine)在极端的pH条件下或者光降解的条件下也能生成三聚氰胺.     

气相色谱-质谱联用法检测保健品中的违禁药物

近年来,随着社会消费水平的不断提高,保健品市场日益兴旺,但暴露出来的问题也十分严重。假冒配方、虚假广告、任意夸大其功效作用的宣传已为社会与公众所关注,而添加违禁合成药物、假化学成分达到或增加其功效作用的行为更具隐蔽性、欺骗性和危害性,为一般消费者所难以识别。因     

Modelling of composting of food waste in a column reactor

The composting of organic solid waste, the mixture of fruit and vegetable leftovers enriched with night soil, was investigated in a closed thermally insulated reactor. It was found that 80.9 % of the original substrate biodegraded after 14 days. A mathematical model of the column reactor was proposed where the biodegradation rate of the organic solid waste was described using simple n-thorder kinetics. A good prediction of process performance was obtained using the proposed kinetics and experimentally obtained reaction heat. Presented at the 33rd International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 22–26 May 2006.     

单分散的二氧化硅微球表面印迹壳层的制备及其对食品包装材料中邻苯二甲酸二苄酯的检测

以邻苯二甲酸二苄酯(DBz P)为模板,以Stber和"种子生长法"相结合获得的二氧化硅微球为载体,采用表面印迹技术成功制备了纳米印迹壳层(MIPs)。采用红外光谱与扫描电镜对其结构和形貌进行表征,同时进行了一系列的吸附性能实验,结果表明,MIPs达到平衡吸附的时间约为30 min,吸附行为符合伪二级动力学。等温吸附实验结果表明,室温条件下MIPs的最大吸附量达47.35 mg/g。对不同温度条件下的等温实验数据进行拟合发现,Langmuir模型与实验数据的吻合度比Freundlich模型更高;Scatchard拟合结果证实该印迹壳层仅含1种结合位点,且印迹位点为均相分布。选择性吸附实验表明MIPs对DBz P的吸附明显高于其他结构类似物。MIPs经10次循环吸附后,吸附效率为83%,表明MIPs具有较长的使用寿命。采用超高效液相色谱(UPLC)技术,以MIPs为吸附剂提取食品包装材料中的DBzP,其加标回收率为88.8%~93.1%,相对标准偏差低于6%。MIPs可作为食品及其包装材料中DBz P提取的备选材料。     

纸基包装材料中抗氧化剂及增塑剂向干性食品模拟物Tenax TA迁移的研究

采用改性聚苯醚多孔聚合物微球Tenax TA为干性食品模拟物,用于纤维素纸基食品接触材料中3-叔丁基-4-羟基苯甲醚(BHA)、2,6-二叔丁基-4-甲基苯酚(BHT)和邻苯二甲酸二环己酯(DCP)向Tenax TA迁移的研究,以超高效液相色谱进行测定。迁移试验以白卡纸和牛皮纸为研究对象,通过设计不同迁移时间和迁移温度下3种目标物向Tenax TA迁移的实验,获取有机化合物从纸基纤维素向Tenax TA迁移的规律。结果表明,有机化合物从纸基材料向多孔聚合物微球的迁移经历了气体吸附和脱附两个步骤。在Tenax TA吸附目标化合物的过程中,纤维素纸基材料的微观孔径尺寸越大,与迁移物的相互作用越小,迁移物迁移的速率越大,Tenax TA的吸附效率越高;当吸附达到平衡后,迁移时间的延长会引发Tenax TA中迁移物的脱附,进而导致目标化合物的迁移率下降。对45种纸基食品接触材料中目标迁移物的筛查表明,BHA和DCP分别存在于两种不同类型的纸基食品接触材料中,迁移量分别为0.027μg/dm~2和0.81μg/dm~2,均小于欧盟指令规定的特定迁移限量。     

气相色谱-质谱联用法测定日用品及食品中9种凉味剂的含量

建立了日用品及食品中薄荷脑等9种新型凉味剂含量的测定方法.样品经乙醇超声提取后,用DB-1701 MS毛细管色谱柱(30 m×0.25 mm×0.25 μm)分离,选择离子监测模式(SIM)进行质谱检测.在优化分析条件下,9种凉味剂分离良好,其在0.25～250 μg/mL浓度范围内线性关系良好,相关系数均大于0.996,除薄荷氧基.1,2丙二醇(0.26 μg/g)外,其余凉味剂的检出限均小于0.1μg/g;在3个不同加标浓度下的平均回收率为82.8％～103.5％,相对标准偏差(RSD,n=6)均不高于3.7％.该方法灵敏、准确、可靠,能较好地分离薄荷脑等9种凉味剂,具有分析时间短、抗干扰性好、定量准确等优点,可为含薄荷(清凉)口味食品的质量控制及未知凉味剂含量样品的分析提供科学数据.