Development of an analytical method for the determination of photoinitiators used for food packaging materials with potential to migrate into milk

Photoinitiators are used in the curing process during UV printing of food carton labels. The alarm concerning the detection of a photoinitiator, 2-isopropyl thioxanthone (ITX), in food samples packed with cartons printed with UV-cured inks has focused the attention of legislative authorities on the potential migrants from packaging inks into foods. For this reason it is very important to carry out analytical methods for the detection of those compounds in food as potential migrants from packaging. The aim of the present work was to develop a multimethod for the analysis of 6 photoinitiators in milk. The selected photoinitiators were Irgacure 184, benzophenone, Irgacure 651, Irgacure 907, Quantacure ITX, and Quantacure EHA (2-ethylhexyl-4-dimethylaminobenzoate). Milk (10 mL) extraction was carried out by using ammoniac and hexane. The supernatant was evaporated and the residue was redissolved with acetonitrile. Then, the extract was analyzed by HPLC-UV. Calibration lines were carried out over the concentration range of 0.1 to 10 mg/L. The calibration data presented high correlation coefficients (>0.9999). Mean recoveries (n = 6) of the 6 photoinitiators were 83.4% (residual standard deviation = 2.3%) at 0.5 mg/kg and 81.0% (residual standard deviation = 4.6%) at 1 mg/kg. Several milk samples and their respective packaging cartons were analyzed. Results were confirmed by HPLC-mass spectrometry.     

Mild and Direct Multiple Deuterium‐Labeling of Saturated Fatty Acids

We have established a mild and direct platinum on carbon (Pt/C)‐catalyzed multi‐deuterium labeling of various saturated fatty acids including bioactive compounds with high deuterium efficiencies in a mixed solvent of isopropyl alcohol and deuterium oxide (i‐PrOH)/D₂O under neutral conditions at 120 °C without the external addition of deuterium or hydrogen gas.

     

SO42－/ZrO2/SBA-15催化丙烯和乙酸合成乙酸异丙酯的研究

水热合成了介孔材料SBA-15，并以其为载体负载固体超强酸SO₄^2－/ZrO₂，得到催化剂 SO₄^2－/ZrO₂/SBA-15，通过XRD对其进行表征。在固定床反应器中，以丙烯和乙酸为原料，研究该催化剂催化合成乙酸异丙酯的活性。对反应条件进行系统地考察，得出最佳反应条件：反应温度140 ℃,反应压力1.2 MPa,空速1 h^－1,n(C₃H₆)∶n(CH₃COOH)=3∶1。在此条件下乙酸异丙酯的产率最高可达79.6％。     

羟丙基壳聚糖对纸质文物保护的应用研究

用环氧丙烷等作醚化剂,在碱性条件下对壳聚糖进行接枝改性。试验得到的壳聚糖改性产物——羟丙基壳聚糖具有良好的水溶性,配制成适当浓度的胶液,喷涂于纸样表面,进行抗张强度测试、耐折度测试、抗干热加速老化试验．光泽度测试等一系列试验,结果表明,纸样保持了原有的质感、光泽、颜色,抗张强度提高了近一倍,耐折度也有提高,羟丙基壳聚糖对纸质文物的加固保护效果明显。     

固定床固体酸催化乙酸/丙烯酯化合成乙酸异丙酯

在固定床反应系统中,考察了几种固体酸催化剂对于乙酸／丙烯酯化反应的催化作用,研究了温度、压力、进料空速以及原料中水的含量对催化剂活性的影响。实验发现：对于ＨＤ－１催化剂,在１３０℃、１１ＭＰａ、乙酸进料空速（ＬＨＳＶ）为２５２ｈ－１的条件下,乙酸单程转化率可达８８６％,生成乙酸异丙酯的选择性可达９９％,催化剂连续运转１００ｈ,活性无明显的变化。     

酶法醇解油茶籽油的研究

在有机溶剂体系中,以油茶籽油和异丙醇为底物,通过脂肪酶催化醇解反应进行油茶籽油改性合成富含油酸的甘油二酯、甘油单酯、异丙酯.考察了溶剂种类、酶种类、底物摩尔比、反应温度和酶加量5个因素对醇解反应的影响.结果表明,最优反应条件为:以叔丁醇为溶剂,脂肪酶Novozyme 435为催化剂,底物异丙醇与油茶籽油摩尔比6∶1,酶加量为底物质量的1％,反应温度55℃.在此条件下反应36 h后甘油三酯转化率达到95.24％,甘油二酯、甘油单酯、异丙酯的含量可分别达到11.58％、8.25％、75.41％.     

乙酸异丙酯-异丙醇物系的热集成变压精馏分离模拟

采用Aspen软件及修正的Wilson模型模拟了压力对乙酸异丙酯-异丙醇物系共沸组成的影响,提出该物系基于热集成的变压精馏工艺。在此基础上,研究了系统能耗随变压精馏工艺两塔压力组合的变化趋势,优化了理论塔板数、进料位置、回流比等操作参数。模拟结果表明,高压塔操作压力为0.60 MPa、减压塔操作压力为0.02 MPa时,热集成系统能耗利用最合理。该压力条件下变压精馏工艺的最优理论塔板数为高压塔26块、减压塔38块;最优进料位置为高压塔第15块理论塔板、减压塔第10块理论塔板;基于热集成工艺的最优回流比为高压塔1.0,减压塔2.0。热集成变压精馏工艺可节能28.5%。     

用色—质联用技术分析工业异丙苯中的有机杂质

利用气相色谱－质谱联用法对工业异丙苯中有的机杂质进行了性分析。通过阿匹松填充柱、ＦＦＡＰ和ＳＥ－５４石英志细管柱气相色谱对工业异丙苯有机杂质的分离比较可知,后者分离效果最佳。１３种有机杂南可以被同时检测,并利用校正面积旭一化法建立了定量分析方法。实验同时发现该方法具有良好的准确度和精确度,可以应用于工业异丙苯的中控分析。     

Intechem-1氟碳表面活性剂溶液性能研究

以六氟丙烯环氧化合物齐聚体为原料,合成一种新型非离子氟碳表面活性剂。测试其表面张力、临界胶束浓度以及发泡性能等物化性质,与Du Pont1157相比,其水溶液表现出更加优异的表面活性,同时在环己烷、汽油和丙酮表面具有良好的铺展性能。