果蔬农药残留清洗研究

挑选市面上3类生物酶类果蔬清洗剂(标记为产品A,B和C)和碱性果蔬清洗剂进行相关农药残留降解实验。利用UPLC-UV测试3种农药的残留量,分析了常见的果蔬农药残留降解剂的作用效果,同时对比了不同反应时间和温度下4种不同农药残留果蔬清洗剂降解效果的影响。     

专利文摘

果蔬残留农药清洗剂专利申请号:CN201010519135.0公开号:CN102453627A申请日:2010.10.25公开日:2012.05.16申请人:郑建明本发明公开了一种果蔬残留农药清洗剂,由下述组分按重量份数组成:脂肪酸聚氧乙烯醚3～5份,烷醇酰胺8～10份,烷基酚聚氧乙烯醚5～7份,次氯     

果蔬中农药残留检测技术及其条件优化研究

农产品质量安全是食品安全的源头,果蔬中的农药残留超标问题是影响食品安全的重要因素。为降低农药残留对人体健康的影响,农残监测至关重要。乙酰胆碱酯酶抑制法是目前较为成熟及常用的速测技术。本文通过对该速测技术过程中,如何控制好检测环节的各项措施及提高检测人员实验水平的讨论,分析了实现果蔬农药残留质量控制的关键因素和检测条件的优化。     

水果蔬菜中二氧化硫残留量的分析

用微库仑法测定保鲜贮存后果蔬表面残留SO_2,简单、快速,与化学分析结果基本一致     

果蔬中氨基甲酸酯类农药残留检测的研究进展

综述了近年来蔬菜水果中氨基甲酸酯类农药残留检测方法的研究进展,主要对果蔬中氨基甲酸酯类农药残留分析的现状(包括样品前处理技术和农药残留检测方法)进行了总结分析,并对蔬菜水果中氨基甲酸酯类农药残留检测方法进行了展望。     

专利摘编

一种果蔬残留农药清洗剂（公告号1151434）一种果蔬残留农药清洗剂,由苯甲酸钠,柠檬酸,香精,水,脂肪醇聚氧乙烯酸,烷醉酰胺6501,乙二胺四乙酸二钠盐,食盐组成。本发明提供的清洗剂对水果及蔬菜表面残留农药的去除率高达99.2％,同时还可将果蔬表面的细菌、霉菌、虫污以及铅、汞等重金属洗涤干净。金银珠宝洗净剂（公告号1144839）本发明是一种金银珠宝洗净剂的制备方法。其关键是在中性溶液中加人还原剂、分散剂、表面活性剂等,有效地对金银珠宝首饰的表面进行纯化,快速溶垢,有效清洗,本产品除了可以对金银珠宝首饰进行清洗外,…     

果蔬中有机磷农药残留检测方法的研究进展

文章综述了果蔬中有机磷农药残留检测的方法。结论如下:色谱检测法检测时间相对稍长,但检测精度高,可为农药残留执法提供依据。光谱技术对样品前处理要求低,对环境污染小。农药残留快速检测法具有结果准确、污染少,成本低的优点。     

蔬菜中农残分析方法及残留农药去除率的研究

建立了一种气相色谱法检测蔬菜中农药残留的测定方法,考察了自制果蔬洗涤盐对蔬菜农药残留的去除率。采用基质固相分散法处理蔬菜样品,弗洛里硅土为固相吸附剂,丙酮/正己烷为洗脱液,各农药回收率在78%~107%,检出限0.003~0.006 mg/kg,定量限0.02~0.03 mg/kg,相对标准偏差小于8%。此方法简单、易操作,可用于评价各类洗涤剂去除农药的效果。为有效去除蔬菜表面残留的农药,以食盐为基本原料,通过复配表面活性剂制备出高效的果蔬洗涤盐,其对有机磷农药敌敌畏、乐果、毒死蜱的去除率在70%~94%,蔬菜中农药残留量均低于国家最高残留限量。     

优化UPLC前处理方法测定果蔬中农药吡虫啉的残留

优化了果蔬中农药吡虫啉的残留前处理方法,样品通过乙腈提取,氯化钠盐析,高效液相色谱法(UPLC)进行上机检测分析。结果表明:该方法具有明显的净化作用,它的线性关系为y=1.589 8x-0.025 4,所得相关系数为R~2=0.999 8,检出限(LODs)为0.003μg/mL,定量限(LOQs)为0.03μg/mL,果蔬中农药吡虫啉的加标回收率为70%~85%。此方法效果良好、简单易行、精密度高,适用于果蔬中农药吡虫啉的残留快速检测。     

微乳型果蔬清洗剂去除农药残留的研究

研究了微乳型果蔬清洗剂对蔬菜表面农药残留的清除效果。向青菜表面喷洒含有乙酰甲胺磷、氧乐果、敌百虫、氯氟氰菊酯的混合农药,并于喷洒后第3天、7天、14天、21天分别进行采集,再采用微乳型果蔬清洗剂、市售去除农残果蔬专用清洗剂和自来水分别清洗。测定青菜中4种农药的残留量,评估3种清洗剂对不同农药、喷洒农药后不同采收时间农残的清除效果。研究结果表明:随着喷洒农药采收时间的延长,青菜中4种农残均有不同程度的降低;但清洗效率明显下降。微乳型果蔬清洗剂对4种农药均有很好的去除效果,对喷洒后第21天采收的青菜中4种农药的平均去除率达63.90%,而市售果蔬清洗剂和自来水的平均去除率仅为44.88%和20.76%。鉴于微乳型果蔬清洗剂良好的增溶性和渗透性,适合于蔬果表皮内部以及疏水性农药残留的去除。     

Reactions in Stabilizer and Between Stabilizer and Nitrocellulose in Propellants

HPLC analysis of the stabilizer is one of the major methods in use for surveillance testing of diphenylamine (DPA) stabilized propellants. Often 0.2% DPA is used as a minimum content for safe propellants. In most cases the propellant can be stored much longer after this limit has been reached without any risk for self‐ignition. We report here about a reaction where DPA bonds to nitrocellulose, leaving a non extractable aromatic stabilizing compound left in the propellant, resulting in a longer time to autocatalysis than predicted. Diphenylnitramine is discussed as a possible intermediary compound occurring from the reaction between DPA and nitrocellulose. This should add to a better understanding of the degradation processes in propellants.     

中国台湾的催化和催化剂的研究开发

本文重点介绍了台湾省各大学和研究院所对催化及催化剂的教学。研究与开发方面动向,相关催化方面学科带头人的研究领域和主要成果,并给出大量参考文献。     

Designer enzyme and cell applications in industry and in environmental monitoring

Renewed world interest in enzyme biotechnological industries now derives from the expectation that many new biocatalysts will be created by genetic engineering associated with protein engineering designer techniques, or by chemical modification of existing enzymes by use of protein tailoring methods. The biocatalysts produced are mainly enzymes, abzymes (catalytic antibodies) and synthesis (synthetic analogues or mimics), and these will be used in industry, synthesis, therapy: and in bioanalysis of components of foodstuffs, and the environment including water, air and soil. The biocatalysts, including whole cells, are firstly incorporated into a particular bioreactor form by use of enzyme engineering techniques such as immobilization, and are then used, as appropriate, to modify their substrates. Improved processing or enhanced products are thereby achieved in the case of manufacturing industry: or monitoring signals are generated, often in the form of a measurable change in current flow, in the case of environmental biosensors. Designer enzymes and cells can be made now for identified applications where the presently available biocatalysts are inadequate, incompatible or uncompetitive.     

Differences in color naming and color salience in Vietnamese and English

The accepted model of color naming postulates that 11 “basic” color terms representing 11 common perceptual experiences show increased processing salience due to a theorized linkage between perception, visual neurophysiology, and cognition. We tested this theory, originally proposed by Berlin and Kay in 1969. Experiment 1 tested salience by comparing unconstrained color naming across two languages, English and Vietnamese. Results were compared with previous research by Berlin and Kay, Boynton and Olson, and colleagues. Experiment 2 validated our stimuli by comparing OSA, Munsell, and newly rendered “basic” exemplars using colorimetry and behavioral measures. Our results show that the relationship between the visual and verbal domains is more complex than current theory acknowledges. An interpoint distance model of color‐naming behavior is proposed as an alternative perspective on color‐naming universality and color‐category structure. © 2003 Wiley Periodicals, Inc. Col Res Appl, 28, 113–138, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10131     

EZH2 Down-Regulation Exacerbates Lipid Accumulation and Inflammation in in Vitro and in Vivo NAFLD

Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent, chronic liver diseases, worldwide. It is a multifactorial disease caused by complex interactions between genetic, epigenetic and environmental factors. Recently, several microRNAs, some of which epigenetically regulated, have been found to be up- and/or down-regulated during NAFLD development. However, in NAFLD, the essential role of the Polycomb Group protein Enhancer of Zeste Homolog 2 (EZH2), which controls the epigenetic silencing of specific genes and/or microRNAs by trimethylating Lys27 on histone H3, still remains unknown. In this study, we demonstrate that the nuclear expression/activity of the EZH2 protein is down-regulated both in livers from NAFLD rats and in the free fatty acid-treated HepG2. The drop in EZH2 is inversely correlated with: (i) lipid accumulation; (ii) the expression of pro-inflammatory markers including TNF-α and TGF-β; and (iii) the expression of miR-200b and miR-155. Consistently, the pharmacological inhibition of EZH2 by 3-Deazaneplanocin A (DZNep) significantly reduces EZH2 expression/activity, while it increases lipid accumulation, inflammatory molecules and microRNAs. In conclusion, the results of this study suggest that the defective activity of EZH2 can enhance the NAFLD development by favouring steatosis and the de-repression of the inflammatory genes and that of specific microRNAs.     

讲授中有研究，学习中有运用

本文从化学反应工程分析的讲授体会出发,分析探讨了硕士学位课程的性质,讲授过程中教材的选取、内容和方法的把握,以及如何根据学生的具体情况,采用更有针对性的课堂讲解的议题。     

高效液相色谱法同时测定蔬菜及水果中的吲哚丁酸和萘乙酸

采用高效液相色谱法,以DiamonsilTMC1(8250mm×4.6mm,5μm)为色谱柱,甲醇∶水∶磷酸为60∶40∶0.35(pH值3~4)作为流动相,检测波长为272nm的条件下测定萘乙酸和吲哚丁酸含量,试验结果表明:在0～50.00mg.L-1范围内线性关系良好,相关系数r吲=0.9998,r萘=0.9998,最低检出浓度为0.025mg.L-1,试样在5.00、10.00、15.00mg.L-13个添加水平下的平均回收率在81.2%~99.4%之间,相对偏差在0.41%~1.61%之间,方法简便,准确。