N,N—二甲基甲酰胺吸收氮氧化物对取代氨基脲的氧化

Ｎ，Ｎ┐二甲基甲酰胺吸收氮氧化物对取代氨基脲的氧化王彩兰王玉炉＊张深松王晓阳李建平（河南师范大学化学系新乡４５３００２）关键词取代氨基脲，ＤＭＦ－ＮＯｘ，氧化，偶氮脲１９９７－０３－１９收稿，１９９７－０７－０２修回国家自然科学基金，河南省自然科学基...     

催化脱氢法合成新型偶氮化合物

催化脱氢法合成新型偶氮化合物王彩兰王玉炉王晓阳李建平王红马东兰（河南师范大学化学系新乡４５３００２）偶氮化合物是一类重要的有机化合物，它被广泛用作染料和分析试剂，还能用于现代科技中的非线性光学材料、油溶性染料等［１］。近来许多研究表明，偶氮苯类衍生物...     

DMSO溶液中有机溶质与尿素、酰胺的Gibbs自由能相互作用参数

ＤＭＳＯ溶液中有机溶质与尿素、酰胺的Ｇｉｂｂｓ自由能相互作用参数张心宽白同春卢雁李强＊（河南新乡师专化学系４５３０００）（河南师范大学化学系新乡４５３００２）酰胺、尿素等模拟生物分子的溶液热力学性质是许多热力学工作者关心的重要课题［１］。一些作者［２...     

磷酸三丁酯－二氧化氮配合物的结构与氧化性能研究

磷酸三丁酯－二氧化氮配合物的结构与氧化性能研究张青枝，张深松，乔仁忠，鲁富贵（河南师范大学化学系，新乡４５３００２）华国雄（河南飞龙精细化学制品有限公司，４５３００３）磷酸三丁酯（ＴＢＰ）是一种给电子化合物，可以和多种化合物形成配合物，因而被广泛地应...     

碱性蓄电池正极用球形微粒Ni（OH）2的制备,性能和结构

碱性蓄电池正极用球形微粒Ｎｉ（ＯＨ）２的制备、性能和结构赵林治＊杨书廷赵培正吕庆章丁立张明春（河南师范大学化学系新乡４５３００２）关键词Ｎｉ（ＯＨ）２，球形微粒，制备，性能，结构，氢氧化镍电极１９９７－０６－１６收稿，１９９７－１１－１７修回国家自然...     

合成乳酸乙酯精馏残液的分析

合成乳酸乙酯精馏残液的分析张青枝，华国雄，鲁富贵，张深松，赵根锁（河南师范大学化学系新乡４５３００２）（河南省化学研究所郑州）关键词乳酸乙酯，精馏残液，红外光谱，电子轰击质谱采用乳酸、乙醇直接酯化法［１］，有机溶剂共沸法［２］，合成乳酸乙酯收率较低。...     

氮的有机元素分析历史和基耶达的贡献

氮的有机元素分析历史和基耶达的贡献魏天俊冯光瑛刘景清（河南师范大学４５３００２）（河南地矿测试中心４５００５３）一、氮的有机元素分析历史［１，２］有机元素分析为有机化学发展做出了很大贡献，成为化学研究和化学工业的有力工具。而氮元素分析方法的进步更是促...     

苄基醚的电解氧化

苄基醚的电解氧化杨健，李毅，李青，王桂兰，李志鸿（河南师范大学化学系，新乡４５３００２）苄基醚断链的研究已有报道，但大都采用化学试剂（氧化剂、催化剂）氧化断裂￣［１－３］。这要消耗大量的化学物质，目前具有实用价值的使醚键氧化断裂的方法还很少￣［４］，...     

含盐混合溶剂气液平衡的线性关系

含盐混合溶剂气液平衡的线性关系刘文彬，王键吉，王彩兰，卢锦梭（河南师范大学化学系新乡４５３００２）１　引言纯物质的气液平衡规律早已被Ｃｌａｕｓｉｕｓ－Ｃｌａｐｅｙｒｏｎ方程所描述；两组分气液平衡的Ｔ－ｐ－ｘ关系也可从热力学理论导出。当少量的非挥发性溶...     

α－Fe_2O_3／SnO_2气敏薄膜的结构与性质

α－Ｆｅ＿２Ｏ＿３／ＳｎＯ＿２气敏薄膜的结构与性质娄向东，杨秀清，李靖华，沈荷生，沈瑜生（河南师范大学化学系新乡４５３００２）（中国科学技术大学材料科学与工程系合肥）关键词α－Ｆｅ＿２Ｏ＿３，ＳｎＯ＿２，双层膜，气敏性能α－Ｆｅ＿２Ｏ＿３具有刚玉结构...     

原子吸收光谱法测定茶叶中铅和镉时消解方法的优化

采用多种方法对同一种茶叶进行消解,用原子吸收光谱法测定不同方法消解的茶叶中有害微量元素铅和镉的含量并进行对比,探索了茶叶中微量元素铅和镉低损耗的最佳消解条件.实验结果表明,不同的消解方式对茶叶中微量元素的测定结果影响很大.测定茶叶中铅和镉元素时,采用硝酸-高氯酸加盖浸泡过夜方法较为理想.     

黑苦荞保健茶中重金属的分析评价

采用原子吸收光谱法和原子荧光光度法测定了四川省凉山州某几个品牌黑苦荞保健茶中的重金属铅、镉、铬、无机砷和汞的含量,并以NY/T 1510-2007标准绿色食品麦类制品为依据,对黑苦荞保健茶重金属污染状况进行了分析评价。结果表明,黑苦荞保健茶受重金属元素污染的程度由高到低表现为铅、铬、镉、无机砷和汞,但含量均未超过国家标准规定;黑苦荞叶芽茶和全株茶的重金属污染较为严重,全胚茶未受重金属污染。     

湛江市不同茶场出品的绿茶茶水中微量元素的测定分析

采用原子吸收法测定了湛江不同茶场出品的绿茶茶水中的锌、铜、铁、钙、镁、锰、镉、镍、铅的含量。结果显示，绿茶茶水中含有较丰富的多种矿物元素和人体必需的微量元素，不同茶场出品的绿茶茶水中微量元素含量有所不同，浸泡次数不同，微量元素含量不同，第一次浸泡的茶水中微量元素的含量明显大于第二次浸泡。     

Calcium(II)-selective potentiometric sensor based on p -isopropylcalix6arene in PVC matrix

In Japan, large amounts of fertilizer nitrogen are applied to tea plantations. We collected samples of tea plantation soil each season for a year. Samples were analyzed for their contents of various inorganic chemicals and total N. Nitrogen was present mainly in the top 0 to 30?cm of soil. However, at times the concentration of nitrate N in the soil water was more than 35?mg?L^?1, even in the deepest layers. The contents of various metal elements in the soil were examined. Ba, Fe, Sr and Zn contents were high in the top 0 to 30?cm of soil. But Al and Mn contents were not always high in the top 0 to 30?cm of soil. From the correlation analysis among contents of various inorganic chemicals, it was suggested that increased leaching of Al, Mn, and Zn from tea plantation soil occurred with increased nitrate N concentration.     

高压密封消解FAAS法分析5种冬青科苦丁茶嫩芽中无机元素及其分布

采集5种冬青科苦丁茶嫩芽样品,经高压密封消解,用火焰原子吸收光谱法测定Ca、Mg、Mn、Fe、Zn的含量。结果表明,在优化的测定条件下,Ca、Mg、Mn、Fe、Zn的回收率为90.1%~105.4%,测定结果的相对标准偏差为1.35%~3.78%(n=5)。用该方法对茶叶标准参考物(GBW 10016)进行了测定,测定结果与标准值相符合。5种冬青科苦丁茶嫩芽中所测元素的含量存在差异,但其总体分布具有一定的相似性,其中苦丁茶冬青嫩芽中Ca和Zn较高。     

常见茶叶中14种元素含量分析及重金属风险评价

采集传统名茶地标产品样品各3种为实验样品,通过ICP-OES和ICP-MS对样品进行K、Ca、Mg、Mn、B、Cu、Fe、Ni、Zn、Cr、Co、Cd、As、Pb等14种元素的含量测定.利用单因素方差分析、主成分分析、污染评价等方法,对茶叶无机元素含量进行分析和污染评价,并对污染来源进行了研究.结果表明,不同产地茶叶样...     

茶叶中微量元素浸出率的研究

采用原子吸收分光光度法测定了茶叶及其浸泡液中微量元素的含量。结果表明，绿茶茶叶中含有较为丰富的多种矿物质元素和人体必需的微量元素，不同的微量元素浸出率不同。     

Study on essential and toxic elements intake from drinking of Chinese tea

Twenty different brands of Chinese tea were analyzed for multiple trace elements, including some essential and toxic elements, by neutron activation analysis (NAA). A comparison among tea brands from China, India, US and other countries was made for the ranges and averages of concentrations for Na, K, Mn, Cu, and Br. It has been observed that the trace element contents in tea leaves are largely dependent upon the soil and the environment where the tea grows. Chinese tea is rich in Mn and Cu comparing with those of other counties surveyed, but is indigent in Na. The transference ratio for each element determined (i.e., the fraction of an element in tea leave transferred into solution when tea is leached by percolation) is also reported. Adult daily intakes of some essential and toxic elements from tea drinking were also estimated.     

Determination of trace elements in drinking tea by various analytical techniques

Tea has been one of the most popular simulating beverages which is both heavily produced and consumed in Taiwan. The determination of minor or trace elements in drinking tea and tea leaves is therefore important for estimating the daily intake of Taiwanese considered as a safety indicator. In order to accurately and precisely determine the concentrations of trace elements in samples, several analytical methods such as AAS, NAA and ICP-AES are suggested. This paper attempts to utilize all three methods to determine the concentrations of minor or trace elements in different types of tea leaves and the extracts percolated from them. The influence of fermentation processes on the concentration levels of minor or trace elements in tea samples is investigated. Because only free metal ions are bioavailable for the human body, it is necessary to determine their concentrations in drinking tea. The dissolution of trace elements in drinking tea is therefore studied by simulating the common Chinese style of tea percolation. Concentrations of thirteen elements including Zn, Mn, Ca, Cu, Ni, Al, K, Mg, Cd, Pb, Na, Co and Sc are determined.     

春砂仁无机成分与药效的研究

采集了阳春县三个产地有代表性的春砂仁．用原子吸收光谱、控制气忿和罩帽电极发射光谱等法，测定其无机成分。结果表明，春砂仁对Zn、Mn有较大富集作用．其含量与春砂仁质量正相关；不同产地春砂仁的挥发油、无机成分与药效成分之间存在差别，证实以金花坑的春砂仁质量最优。