阳极溶出伏安法测定氯化锌-氯化铵电解制锌体系中铅和镉

采用阳极溶出伏安法,建立了在ZnCl₂-NH₄Cl体系中,使用乙二胺四乙酸二钠(EDTA)和磺基水杨酸消除Cu²⁺对Pb²⁺测定的影响,不经预分离同时测定溶液中Pb²⁺和Cd²⁺的方法。在扫描电位为-0.80～-0.30 V、富集电位为-0.85 V、富集时间为100 s、扫描速率为0.015 V/s的优化试验条件下,Pb²⁺和Cd²⁺分别在-0.48 V和-0.68 V处有灵敏的溶出峰。溶液中可能存在的常见离子不干扰测定。Pb²⁺、Cd²⁺浓度分别在9.7×10^-9～2.4×10^-4、1.8×10^-8～8.9×10^-5 mol/L范围内与其峰电流呈良好的线性关系,相关系数分别为0.995和0.998。方法中Pb²⁺、Cd²⁺的检出限分别为3.9×10^-9、1.9×10^-9 mol/L。采用实验方法测定了ZnSO₄电解液和ZnCl₂-NH₄Cl电解液中的Pb²⁺和Cd²⁺,结果的相对标准偏差(RSD,n=6)分别为0.83%～2.1%、0.56%～0.75%,回收率分别为89%～108%、92%～104%。     

Effects of saline stress on mineral composition,phenolic acids and flavonoids in leaves of artichoke and cardoon genotypes grown in floating system

BACKGROUND: Cynara cardunculus is a species native to the Mediterranean basin. It includes globe artichoke and cultivated cardoon as well as their progenitor wild cardoon. The species is a source of biophenols, and its leaf extracts have been widely used in herbal medicine as hepatoprotectors and choleretics since ancient times. The aim of this study was to determine the effect of increasing the level of salinity in the nutrient solution (1 or 30 mmol L^?1 NaCl) on biomass production, mineral composition, radical‐scavenging activity, caffeoylquinic acids and flavonoids in three artichoke (‘Romolo’, ‘Violetto di Provenza’ and ‘Violetto di Romagna’) and three cultivated cardoon (‘Bianco Avorio’, ‘Bianco Gigante Inerme’ and ‘Gigante di Romagna’) cultivars grown in a floating system. RESULTS: Increased salinity in the nutrient solution decreased the leaf dry biomass and leaf number of artichoke and cultivated cardoon cultivars. Salinity reduced macro‐ and microelement accumulation in leaves (e.g. N, K, Ca, Mg, Fe, Mn and B) but improved their antioxidant activity, total polyphenols, chlorogenic acid, cynarin and luteolin. The cultivated cardoons, especially ‘Bianco Avorio’ and ‘Gigante di Romagna’, showed higher biomass and leaf number than those observed in artichoke genotypes. ‘Violetto di Provenza’ exhibited the highest content of chlorogenic acid, closely followed by ‘Violetto di Romagna’, whereas for cynarin content the highest values were recorded in ‘Violetto di Provenza’, ‘Bianco Avorio’ and ‘Gigante di Romagna’. The highest content of luteolin was recorded in ‘Gigante di Romagna’ and ‘Bianco Avorio’, while the highest content of apigenin was observed in ‘Gigante di Romagna’. CONCLUSION: The results showed that the floating system could be considered an effective tool to improve quality aspects through proper management of the salt concentration in the nutrient solution. They also suggest that specific cultivars should be selected to obtain the desired profile of bioactive compounds. © 2012 Society of Chemical Industry     

Purification and structural characterisation of lipid transfer protein from red wine and grapes

Lipid transfer proteins (LTP) play a major role in plant defence and are of particular interest due to their known ability to cause allergic reactions. These proteins are expressed in grapes and also remain detectable after vinification, especially in red wine. However, it remains unknown whether the protein undergoes any changes during the vinification process. Here, we present a purification method for LTPs from Dornfelder grapes and wine. By liquid-chromatography–mass spectroscopy (LC–MS/MS) we identified LTPs from two different species (Vitis vinifera and Vitis aestivalis). Additionally, the purified LTPs were characterised using spectrometric methods, confirming their high purity and structural stability during vinification. We conclude that LTPs are resistant to the alcohol content (13.5 vol%), acidic milieu of wine and other ingredients present during the vinification process, indicating that the allergenic potential of grape LTP is not diminished by the vinification process.     

钾混盐矿生产氯化钾尾盐利用研究

将氯化钾车间副产尾盐用淡水溶解后,用新老卤进行兑卤,观测其蒸发结晶路线,为尾盐的成矿再利用提供重要数据参数.     

草莓复合涂膜保鲜效果的研究

以草莓为实验原料,采用魔芋精粉、丁香提取物和氯化钙复合涂膜方法对草莓进行涂膜保鲜实验。选择失重率和Vc含量为指标,以单因素实验和正交实验优化保鲜膜配方,结果表明,常温下,魔芋精粉浓度0.5%、丁香提取物浓度2.0%、氯化钙浓度1.2%的复合涂膜剂对草莓的保鲜效果最好,有效地延长了保质期。该最佳配比的复合涂膜剂在低温下对草莓的保鲜效果比在室温下更显著,相关指标明显优于室温下的涂膜组。     

织物涂层剂研究新进展

纺织品涂层整理剂简称涂层剂,是指一种均匀涂布于织物表面能形成薄膜的高分子类化合物.阐述了近年来新研发的一些织物涂层剂(如新型聚丙烯酸酯类涂层剂、聚氨酯类涂层剂、聚氯乙烯类涂层剂、有机硅类涂层剂)的制备、特性及应用,指出了今后织物涂层剂的研究方向:绿色环保型、特殊功能型、“智能”化、多功能型.     

双活性基固色剂的合成及应用

以二甲基二烯丙基氯化铵(DMDAAC)和烯丙基缩水甘油醚(AGE)为原料,过硫酸钠为引发剂,合成了一种环保型双活性基固色剂P(DMDAAC-AGE).通过FT-IR、TG-DTA和SEM等表征了固色剂的结构和性能.讨论了影响固色剂P(DMDAAC-AGE)性能的主要因素.合成P(DMDAAC-AGE)的优化工艺条件为:单体n(AGE)∶n(DMDAAC)=1∶2,在水相介质中,反应混合液中总单体初始质量分数为30%,引发剂0.75%(对单体质量),引发剂和原料AGE的加料方式为连续滴加,80℃保温反应6 h.将合成的固色剂用于活性染料染棉织物的固色,湿摩擦牢度可达4级,干摩擦牢度可达4～5级,皂洗沾色牢度可达4级.     

食盐中氯化钠测定的研究

食盐是人们日常生活中必备的调味品,氯化钠是食用盐的主要成分,是食盐咸味的主要来源。作为食盐生产企业必须控制的指标,氯化钠项目的检测尤为重要,但是不同产品标准规定的氯化钠的检测方法存在着或多或少的差别,常用的氯化钠测定方法为计算法,一个项目涉及到5个项目的检测,且计算过程繁琐。本研究根据食盐中杂质化合物的不同将食用盐分成几个类型,将复杂的计算过程列表表示,使计算过程变得清晰明了。同时汇总了现行食用盐标准中氯化钠含量的测定方法幵迚行了比较分析,以期给管理部门、生产企业及检验人员提供更多的参考和思考。     

液相色谱串联质谱测定狗肉中的氯化琥珀胆碱

用Na_2CO_3—NaHCO_3缓冲盐震荡超声提取狗肉的氯化琥珀胆碱,过WCX固相萃取柱净化,液相色谱三重四极杆串联质谱定性、定量。结果表明,氯化琥珀胆碱在0.5~250.0ng/mL浓度范围内线性关系良好(r=0.999 87),回收率达96%以上,精密度小于13%,检出限为0.004 mg/kg。因此,该方法可用于狗肉中氯化琥珀胆碱快速、灵敏、准确的测定。