Structure, properties and application to water-soluble coatings of complex antimicrobial agent Ag-carboxymethyl chitosan-thiabendazole

The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.

Development of controlled release formulations of thiabendazole

This study aimed to develop controlled release formulation of Thiabendazole for reduced contaminations to soil water and agricultural produces. The idea behind this work was based on changing the ionization status of Thiabendazole molecule throughout pH changes to become a cation then adsorbing it to bentonite clay surfaces. Equilibrium concentrations of Thiabendazole in the adsorption solutions were determined by HPLC. Results showed that Thiabendazole was better adsorbed in clay at the lowest pH value (pH 3). Furthermore, raising the temperature of the adsorption reaction increased the adsorbed amount of Thiabendazole. Release experiments showed that Thiabendazole is extremely slower at pH 3 than at pH 5.5 or pH 9. These promising results suggest that application of Thiabendazole clay based formulation may reduce the applied rate and that the released fraction consequently may reduce the environmental contamination. It is also advantageous to use these formulations in the acidic soil for plant disease control.

Crystal Structure of a Mn(Ⅱ) Coordination Polymer:[Mn(TP)(TBZH)_(2n)(TBZH=Thiabendazole,TP=Terephthalic Acid)

The structure of a manganese（Ⅱ） polymer,[Mn（TP）（TBZH）]2n 1（TBZH=thiabendazole,TP=terephthalic acid）,has been determined by X-ray crystallography and characterized by elemental analysis,IR spectrum and thermogravimetric analysis.It crystallizes in the orthorhombic system,space group Pbcn with a=12.7813（12）,b=10.7544（10）,c=20.1270（19）A,V=2766.6（4）A^3,Z=8,C14H9Mn0.50N3O2S,Mr=310.77,Dc=1.492g/cm^3,F（000）=1268,μ=0.674 mm^-1 and S=1.064.The 1-D chain architecture of 1 is constructed from terephthalic acid and manganese atoms.Hydrogen bonds and aryl ring π-π stacking interactions in 1 contribute to form a 3-D supramo-lecular structure.

Crystal Structure of a Cu(Ⅱ) Coordination Polymer: [Cu(IP)(TBZH)]_(2n) (TBZH = Thiabendazole, IP = Isophthalic Acid)

The structure of a copper（Ⅱ） polymer, [Cu（IP）（TBZH）]2n 1 （TBZH = thiabendazole, IP = isophthalic acid）, has been determined by X-ray crystallography and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. It crystallizes in the monoclinic system, space group P21/n with a = 11.76, b = 10.41, c = 14.08A^°, β = 104.80°, V= 1666.0（3）A^°^3, Z = 4, Mr= 428.90, Dc= 1.710 g/cm^3, F（000） = 868,μ = 1.468 mm^-1 and S = 1.001. The 2-D layered gridding architecture of 1 is constructed from isophthalic acid and binuclear copper atoms. Hydrogen bonds and aryl ring π-π stacking interactions in 1 contribute to a supramolecular structure.

Rapid determination of thiabendazole in orange extract using excitation-emission matrix fluorescence and second-order calibration based on alternating trilinear decomposition/alternating normalization-weighted error algorithms

A novel approach is proposed for direct quantitative analysis of thiabendazole in the orange extract by using excitation-emission matrix fluorescence coupled with second-order calibration methods based on the alternating trilinear decomposition(ATLD) and the alternating normalization-weighted error(ANWE) algorithms,respectively. The average recoveries of thiabendazole in the orange extract by using ATLD and ANWE with an estimated component number of two were 99.7 ± 3.3% and 103.5 ± 4.1%,respectively. Furthermore,the accuracy of the two algorithms was also evaluated through elliptical joint confidence region(EJCR) tests as well as figures of merit,such as sensitivity(SEN),selectivity(SEL) and limit of detection(LOD). The experimental results demonstrate that both algorithms have been satisfactorily applied to the determination of thiabendazole in orange extract,and the perform-ance of ANWE is slightly better than that of ATLD.

Thiabendazole inhibits ubiquinone reduction activity of mitochondrial respiratory complex Ⅱ via a water molecule mediated binding feature

The mitochondrial respiratory complex Ⅱ or succinate:ubiquinone oxidoreductase(SQR)is a key membrane complex in both the tricarboxylic acid cycle and aerobic respiration.Five disinfectant compounds were investigated with their potent inhibition effects on the ubiquinone reduction activity of the porcine mitochondrial SQR by enzymatic assay and crystallography.Crystal structure of the SQR bound with thiabendazole(TBZ)reveals a different inhibitor-binding feature at the ubiquinone binding site where a water molecule plays an important role.The obvious inhibitory effect of TBZ based on the biochemical data(IC50~100μmol/L)and the significant structure-based binding affinity calculation(~94μmol/L)draw the suspicion of using TBZ as a good disinfectant compound for nematode infections treatment and fruit storage.

固相萃取富集-高效液相色谱法测定环境水中多菌灵和噻菌灵

建立了以固相萃取技术富集,高效液相色谱法进行分离和检测多菌灵和噻菌灵2种杀菌剂的方法。环境水中的多菌灵和噻菌灵用3MEmpore6mLC18Cartridge进行固相萃取。以HypersilODS柱为分析柱,优化得到高效液相色谱分离条件流动相为甲醇水(50∶50,V/V);流速为0.7mL/min;柱温为55℃;在286nm波长下检测,检出限为0.05mg/L。本法操作简便,灵敏,回收率高。

高效液相色谱法同时测定甜瓜样品中的抑霉唑和噻菌灵

提出了一种用高效液相色谱法 (HPLC)同时测定甜瓜样品中的抑霉唑和噻菌灵残留量的方法。用乙酸乙酯作提取剂提取甜瓜样品 ,通过一个净化步骤分离样品中共提取组分。采用InertsilC8 3色谱柱 (15 0mm× 4 .6mm ,5 μmi.d ,) ,流动相为乙腈∶水 =75∶2 5 ,外标法定量 ,方法的检出限噻菌灵为 0 .70ng ,抑霉唑为1.5 3ng ;回收率为 87.5 %～ 98.0 % ;相对标准偏差为 1.5 %～ 4 .2 %。本法用于甜瓜样品中抑霉唑、噻菌灵含量的测定 ,获得了满意的结果。

固相微萃取-高效液相色谱-荧光检测法测定番茄中的多菌灵和噻菌灵

建立了应用固相微萃取(SPME)-高效液相色谱(HPLC)-荧光检测法测定番茄中多菌灵(MBC)和噻菌灵(TBZ)的分析方法.考察了萃取纤维、萃取时间、萃取温度、解吸时间、解吸液组成、解吸模式、pH值、有机溶剂和离子强度对MBC和TBZ萃取效率的影响,对SPME条件和色谱条件进行了优化.SPME在室温下进行,采用65 μm聚二甲基硅氧烷/二乙烯苯(PDMS/DVB)萃取纤维,萃取溶液中加入100 g/L NaCl,搅拌速度为1 100 r/min,萃取时间为50 min.将该法用于番茄中MBC和TBZ的测定,MBC和TBZ的定量线性范围均为0.01～1.0 mg/kg;线性相关系数分别为0.995 8和0.996 7;检出限分别为0.003和0.001 mg/kg;回收率分别为83.5%和85.6%(n=5),相对标准偏差(RSDs)分别为6.5%和3.8%.该方法操作简单,无需使用有机溶剂,适于分析番茄样品中的MBC和TBZ.

分散固相萃取—高效液相色谱法测定水果中多菌灵和噻菌灵

分析了现行苯并咪唑类农药残留检测方法中存在的问题,并对分散固相萃取—高效液相色谱法检测苯并咪唑类农药残留方法进行了研究。通过对方法的条件进行优化、改进,获得高效、快捷、经济的前处理方法,成功建立了分散固相萃取—高效液相色谱法。其中使用C18和PSA吸附剂组合将多菌灵的回收率由文献中大于110%降到91.8%～104.7%,噻菌灵的回收率由文献中的17%～44%提高到88%～102%,满足了要求。在苹果、香蕉、桃、柑橘、葡萄、草莓6种水果上进行方法验证,研究结果表明,农药浓度在0.01～3.0mg/kg内呈良好的线性关系,线性相关系数在0.999以上,平均回收率在88%～104.7%,方法的RSD值小于5%。方法的准确度和精密度都满足要求,为相关标准的制定提供了依据。

液相色谱-质谱法同时测定甜瓜样品中的噻菌灵、甲基托布津、扑海因

采用液相色谱 质谱法同时测定甜瓜样品中的噻菌灵、甲基托布津和扑海因含量。离子化技术采用大气压电喷雾 (+)方式 ,定量测定使用选择离子监测模式。检测离子m /z :2 0 2 .2 5、343.2 8、331 .0 7。检出限 :噻菌灵为 0 .1 pg ,甲基托布津为 1 0 .2pg ,扑海因为 2 .4 2ng ;回收率为 81 .0 %～ 1 1 0 % ;相对标准偏差为1 5 %～ 1 6 .8%。方法灵敏度高 ,选择性好 ,准确度高 ,用于甜瓜样品中噻菌灵、甲基托布津、扑海因的测定 。

HPLC法测定常见蔬菜水果中多菌灵、噻菌灵和苯菌灵残留量

建立了植物源性食品中多菌灵、噻菌灵和苯菌灵的高效液相色谱多残留简捷并可靠的检测方法。样品经乙腈提取,MCX固相萃取柱净化后,采用HPLC法测定,以甲醇-0.1%甲酸水溶液为流动相,1.0 mL/min等度洗脱,在0.1～20μg/mL范围内,多菌灵和噻菌灵的峰面积与其浓度呈线性相关,R≥0.9998,检出限均为25μg/kg,添加回收率91.0%～103.5%,变异系数0.44%～8.96%。

噻菌灵在柑橘、香蕉和芒果贮藏期的残留降解研究

为了解柑橘、香蕉和芒果贮藏期间使用噻菌灵后的降解情况及其对果实安全性的影响,用高效液相色谱法对果肉中噻菌灵的残留水平进行了分析。样品中的噻菌灵经乙腈提取,乙二胺-N丙基硅烷(PSA)吸附剂、C18吸附剂(ODS)和无水硫酸镁净化后,测定残留量。添加0.2～1.0 mg/kg浓度水平噻菌灵,在3种水果中的平均添加回收率为87.6%～104.8%,相对标准偏差(RSD)均在7%以下,噻菌灵最低检出限为0.002 5 mg/kg,满足残留分析的要求。结果表明,贮藏期间使用噻菌灵后,果肉中噻菌灵残留量随时间延长先增加后减少;在试验使用水平下,果肉中噻菌灵残留低于我国、国际食品法典委员会(CAC)欧盟和美国规定的最大残留限量要求,其残留污染性较小,不会对果实安全质量造成负面影响。

保鲜剂处理对银杏果采后生理及贮藏品质的影响

【目的】探讨保鲜剂在银杏果贮藏保鲜中的应用效果。【方法】以银杏果主栽品种大佛指为试材,分别采用二氯异氰尿酸钠熏蒸、G型二氧化氯片剂、FK葡萄保鲜片剂以及噻苯咪唑悬浮剂处理银杏果,研究其在4℃冷藏过程中的生理生化及相关营养和贮藏品质的变化规律。【结果】采用噻苯咪唑悬浮剂浸泡处理银杏果,可有效抑制贮藏期间银杏果呼吸强度及MDA含量的升高,保持较低的细胞膜透性;贮藏末期,经噻苯咪唑处理的银杏果POD活性和CAT活性较高,分别为1970.3 U.g-1,826.2 U.g-1;噻苯咪唑处理可延缓银杏果还原糖、可溶性总糖的生成,保持淀粉含量在较高的水平,贮藏末期淀粉含量为21.39%;噻苯咪唑溶液浸泡也可使银杏果含水量增加;噻苯咪唑处理还可抑制银杏种仁霉变的发生,保持较高好果率。【结论】噻苯咪唑悬浮剂处理银杏果,可以保持其贮藏品质,延长其贮藏寿命,贮藏效果优于其它保鲜剂。

噻菌灵农药的表面增强拉曼光谱分析

利用表面增强拉曼光谱技术(SERS)分析噻菌灵农药的拉曼特征峰。采用微波法制备银溶胶表面增强基底,利用激光显微共焦拉曼光谱仪分别采集514.5和785nm激发波长下的噻菌灵农药拉曼光谱,解析不同激发波长下的拉曼特征峰并进行比较。结果表明:不同激发波长下噻菌灵的拉曼峰强度和拉曼频移差异较大,514.5nm激发波长下的782和1 012cm-1最强,是C—H变形振动较强特征峰,而785nm激发波长下的1 284,1 450和1 592cm-1最强,是环振动和CN伸缩振动较强特征峰。对比分析各个激发波长下噻菌灵的SERS谱图,找到了噻菌灵农药的5个较强特征拉曼峰:782,1 012,1 284,1 450和1 592cm-1。这些特征峰可作为食品及农产品中噻菌灵农药残留定性定量判别的依据。

超高效液相色谱-串联质谱法测定莲雾中多菌灵、噻菌灵和甲霜灵残留

建立了莲雾中多菌灵、噻菌灵和甲霜灵残留的超高效液相色谱-串联质谱（UPLC-MS/MS）的快速检测方法。样品直接用乙腈匀浆提取,过0.22μm滤膜后,在电喷雾正离子模式下以多反应监测（MRM）模式测定,基质匹配标准溶液外标法定量。结果表明：方法的线性范围为0.01~0.5μg/m L,决定系数（R2）〉0.99;在0.04、0.4和2 mg/kg 3个添加水平下,方法的平均回收率为75%~107%,相对标准偏差为2.0%~8.9%（n=5）,定量限均为0.04 mg/kg。该方法样品前处理简单、快速,分析时间短,灵敏度、准确度和精密度均符合农药残留检测要求。

固相萃取-高效液相色谱法同时测定噻菌灵和多菌灵在浓缩菠萝汁中的残留量

建立了一种可同时测定浓缩菠萝汁中噻菌灵和多菌灵残留量的反相高效液相色谱分析法.浓缩菠萝汁样品与水按一定比例稀释后,经过调节溶液的pH值、离心、过滤,用混合相固相萃取小柱（Mixed-mode SPE）进行提取、净化,并用配有二极管阵列检测器（DAD）的液相色谱仪检测,外标法定量.使用噻菌灵和多菌灵对照品进行添加回收率测定,结果显示,本方法对噻菌灵的检出限为0.020 mg/kg,回收率为75.7%～93.3%;对多菌灵的检出限为0.020 mg/kg,回收率为80.8%～99.2%;测定的相对标准偏差均不大于5.7%.本方法简单、快速、准确,能满足常规噻菌灵和多菌灵残留量检测的需要.

高效液相色谱法测定柑橘中多菌灵、噻菌灵、甲基硫菌灵和硫菌灵残留量

应用高效液相色谱法测定了柑橘中多菌灵、噻菌灵、甲基硫菌灵和硫菌灵的残留量。样品用乙腈提取后，经氨基活性碳复合固相萃取小柱净化处理，以甲醇-水混合溶液为流动相梯度洗脱，经ZORBAX Extend-C18（150mm×4．6mm，5μm）色谱柱分离，在267nm波长处，用紫外检测器检测。4种菌灵农药的质量浓度在0．1～10．0mg·L^-1范围与其峰面积呈线性关系，检出限（3S／N）均为0．05mg·kg^-1。方法对多菌灵、噻菌灵、甲基硫菌灵和硫菌灵的平均回收率在75．0％～98．7％之间，相对标准偏差（n=7）在3．2％～14．3％之间。

浓缩刺梨汁中噻菌灵和多菌灵残留量的高效液相色谱法测定

研究了一种可同时测定浓缩刺梨汁中噻菌灵和多菌灵残留量的固相萃取-高效液相色谱法。浓缩刺梨汁样品与水按一定比例稀释后，经过调pH、离心、过滤，用混合相固相萃取小柱（Mixed—mode SPE）进行提取、净化，用配有二级管阵列检测器（DAD）的液相色谱仪检测，外标法定量。用噻菌灵和多菌灵对照品进行添加回收率测定，结果显示本方法对噻菌灵的测定低限为0．020mg／kg，回收率为77．5％～87．1％；对多菌灵的测定低限为0．020mg／kg，回收率为74．0％～96．3％；测定的相对标准偏差均不大于7．4％。本方法能满足常规噻菌灵和多菌灵残留量检测的需要。

羧甲基壳聚糖银噻苯咪唑的制备及其抑菌性能

研究了一种新型广谱复合抗菌剂羧甲基壳聚糖银噻苯咪唑的制备与性能。抗菌实验结果表明:该新型复合抗菌剂能综合其单一组分抗菌剂或二元组分(羧甲基壳聚糖银和羧甲基壳聚糖噻苯咪唑)复合抗菌剂的优点,对大肠杆菌、金黄色葡萄球菌、白色念珠菌、黑曲霉和毛霉等代表性微生物的最小抑菌浓度分别为20×10-6、25×10-6、20×10-6、40×10-6和450×10-6 g/mL,具有优良的广谱抗菌效果;同时,克服了银离子的变色缺陷;银和噻苯咪唑分别与高分子羧甲基壳聚糖中的胺基和羧基发生了键合作用。