电感耦合等离子体质谱法快速测定苦荞茶中铜、铅、镉、钴、镍

建立了用硝酸-高氯酸消解样品,电感耦合等离子体质谱法(ICP-MS)测定苦荞茶中铜、铅、镉、钴、镍的方法.方法具有灵敏度高、检出限低、精密度好、基体干扰少、准确可靠、快捷、简便的特点.各元素方法检出限(3SD,μg/L)分别为:铜0.009、铅0.023、镉0.015、钴0.022、镍0.035;方法精密度(RSD,n=12)分别为:铜2.5%～3.0%、铅2.1%～2.3%、镉3.0%～3.8%、钴2.5%～2.6%、镍1.5%～1.9%;各元素加标回收率分别为:铜95.0%～105.0%、铅95.0%～105.0%、镉98.0%～105.0%、钴95.0%～105.0%、镍95.0%～105.0%.在线用铑作为内标95.0%～105.0%.方法经国家一级标准物质验证,测定值与标准值吻合.应用于实际样品测定,结果满意.     

超高效液相色谱串联质谱法快速检测烤鳗虾中硝基呋喃代谢物残留新技术

采用高检测灵敏度超高效液相色谱串联质谱开发了烤鳗虾中硝基呋喃代谢物残留量快速检测新技术.该技术包括2-氯苯甲醛为衍生剂,试剂盒方法快速样品制备,高检测灵敏度超高效液相色谱串联质谱快速测定.设计了4个添加水平(0.2、0.5、1.0、2.0 μg/kg)、8次重复的试验.结果表明,方法线性范围0～5.0 μg/kg;检测限均为0.2μg/kg;AOZ回收率89.2%～100.6%,RSD2.2%～12.6%;AMOZ回收率91.3%～107.4%,RSD 4.3%～8.7%;SEM回收率79.9%～118.0%,RSD 2.4%～12.3%和A皿回收率78.9%～105.0%,RSD3.7%～12.1%.该快速检测方法小批量(20个样品)检测周期少于5.5h.     

敌百虫在棉花和土壤中的残留研究

建立了敌百虫在棉花和土壤中残留量的高效液相色谱-电喷雾质谱(HPLC-ESI/MS)测定方法.该方法最小检出量为1.5×10-11 g,最小检出浓度在植株和土壤中均为0.05 mg/kg,加样回收率为植株71%～76%、土壤96%～103%、棉籽74%～79%,相对标准偏差分别为3.2%～16%、5.2%～12%、4.8%～6.5%.本法快速、灵敏、准确,可以用于敌百虫的残留分析.降解动态和最终残留研究结果表明,敌百虫在植株和土壤中的半衰期(T50)分别为0.4～0.6 d和0.5～1.2 d;以推荐剂量施药2～3次,或以2倍推荐剂量施药2～3次,采收间隔21 d,棉籽和土壤中敌百虫残留量均低于0.05 mg/kg.     

多环芳烃混合物的快速同步荧光光谱分析

建立了胶束溶液中多环芳烃混合物同时测定的同步荧光分析法.该法简便快速,无需对混合物进行分离,可实现11种组分的同时鉴别和定量测定.方法的检出限在0.013～3.2 ng·mL-1之间,相对标准偏差为1.05%～1.45%.此方法应用于分析河水、池塘水、污水中多环芳烃均取得了良好的效果,回收率分别为80.4%～115%、83.4%～101%和80.5%～95.9%.     

HPLC—ICP—MS法对动物源性食品中阿散酸、硝苯砷酸与洛克沙砷残留量的同时测定

建立了动物源性食品中阿散酸(ASA)、硝苯砷酸(NPAA)和洛克沙砷(ROX)的HPLC-ICP-MS分析方法.研究了液相色谱和ICP-MS条件并对提取剂进行了优化.在0 ～100 μg/L范围内阿散酸、硝苯砷酸和洛克沙砷的线性关系良好,线性相关系数均大于0.998; 阿散酸、硝苯砷酸、洛克沙砷检出限分别为2.75、3.85、4.20 μg/kg;保留时间的相对标准偏差(RSD)不大于0.12%.5种样品中3个添加水平的平均回收率为阿散酸86% ～99%,硝苯砷酸79% ～95%,洛克沙砷82% ～98%;相应的RSD分别为2.9% ～8.6%、2.8% ～7.9%、3.3% ～8.1%.     

石墨炉原子吸收法测定美白化妆品中铅和镉

本文采用石墨炉原子吸收法测定了美白化妆品中铅、镉含量.铅、镉测定的线性范围分别为0～176 ng/mL、0～88 ng/mL,相关系数r均为0.9998,回收率分别为98.2%～101.1%和98.9%～101.8%,相对标准偏差分别为1.73%和1.46%.     

西红柿、卷心菜中残留丙溴磷的提取及气相色谱-火焰光度检测法分析

 报道了一种简便、快速的西红柿、卷心菜中丙溴磷的提取净化及测定方法。采用丙酮 正己烷 (体积比为 1∶1)提取西红柿、卷心菜中的丙溴磷 ,经活性炭净化后 ,用气相色谱 火焰光度检测法直接测定其含量。丙溴磷在西红柿、卷心菜中的加标回收率分别为 96 .2 %～ 10 5 .9% ,94.7%～ 10 2 .3% ,RSD分别为 3.7%～ 4.9% ,3.7%～5 .0 %。西红柿、卷心菜中丙溴磷的最低检出限为 0 .0 6mg/kg。     

微波辅助提取-气相色谱法同时测定中草药中有机磷和氨基甲酸酯农药残留

建立了中草药中有机磷和氨基甲酸酯类农药同时检测的气相色谱分析新方法.中药材试样依据正交实验的优化条件,用正己烷-丙酮(1∶4,V∶V)混合提取剂进行微波辅助提取,经弗罗里硅土和中性氧化铝混合层析柱净化后,采用HP-5毛细管柱分离,氮磷检测器同时检测中草药中15种有机磷和6种氨基甲酸酯类农药残留量.21种农药在0.01～1.0 mg/L的浓度范围内线性良好,线性相关系数为0.9950～1.000,检出限为0.002～0.01 mg/L.在0.05、0.2、0.5 mg/kg三个添加水平的平均回收率分别为75.11%～128.57%、75.85%～120.71%和76.43%～117.25%,相对标准偏差分别为 3.10%～10.58%、5.27%～9.94%和4.03%～9.03%.方法用于中草药中有机磷和氨基甲酸酯类农药残留的同时检测,结果良好.     

悬浮液进样-火焰原子吸收光谱法测定百合中的微量元素梁保安

将处理后的百合研磨成粒度小于0.1 mm的粉状物, 加入稳定剂琼脂制成悬浮液, 用LaCl3和CsCl消除相关干扰, 采用标准加入法在同一试液中利用空气-乙炔火焰原子吸收光谱法测定Zn、 Mn、 Fe、 Cu、 Ca、 Mg、 K、 Na 8种元素. 结果表明, 兰州百合中Zn、 Mn、 Fe、 Cu、 Ca、 Mg、 K、 Na的质量分数分别是162.0、 5.0、 30.8、 8.4、 295.9、 574.2、 522.9、 291.6 μg/g. 加标回收率分别为: Zn 99.4%～100.5%、 Mn 98.0%～101.8%、 Fe 92.7%～97.5%、 Cu 99.9%～102.9%、 Ca 96.0%～100.0%、 Mg 93.3%～102.5%、 K 91.7%～103.8%、 Na 99.1%～105.0%. 以传统湿法的测定结果为参考对测定值进行t检验, 发现两者无显著性差异, 说明悬浮液进样法的测定结果准确可靠.     

原子吸收光谱法测定芦苇中重金属(铜、锌、铅、镉)

采用密封高压消解样品,火焰原子吸收光谱法测定了芦苇中锌的含量,石墨炉原子吸收光谱法测定了芦苇中铜、铅、镉的含量.结果表明:铜、锌、铅和镉在芦苇不同部位的回收率分别为85.0%～120.4%,86.4%～106.5%,85.3%～86.2%和104.0%～114%;各元素分析结果精密度(RSD)分别为Zn0.72%～4.08%,Cu4.08%～6.27%,Pb4.12%～8.47%,Cd2.33%～5.59%,测定方法简便、准确,此方法的建立将为后继研究芦苇对重金属的吸收与积累,以及芦苇作为一种重金属污染指示性植物的利用提供技术支持.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.