浙江不同地区银杏叶中微量元素的研究

用荧光分光光度法和能量色散X荧光分析法测定了浙江不同地区银杏叶中某些微量元素含量的变化。结果表明:不同地区的银杏叶中微量元素硒、铜、锌、铬、铁和锰的含量范围分别为0.1～2.17×10~(-6),2.8～6.9×10~(-6),6.1～17.1×10~(-6),1.1～6.6×10~(-6),74～399×10~(-6)和15～73×10~(-5).     

大肠癌与七种元素关系的分析

用原子吸收光谱法测定了38例大肠癌组织及其边缘组织中铬、锰、锌、铁、镁、钙、铜的含量.结果表明,癌组织中锰含量(0.281±0.179)×10-6,镁含量(76.85±17.66)×10-6,高于其边缘组织(P＜0.01).七种元素含量与大肠癌的病理类型及分化程度无关.提示,大肠癌的发生与锰、镁的含量变化有关.     

胃癌与七种元素关系的分析

57例胃癌癌灶内锌值为(13.740±4.150)×10~(-6),低于癌边缘组织(15.677±4.567)×10~(-6)(P<0.01),亦低于正常组织(15.897±3.580)×10~(-6)(P<0.01)。癌灶铜值为(7.91±6.19)×10~(-6),高于正常组织(5.62±12.01)×10~(-6)(P<0.05),癌灶铜/锌比值亦高于正常组织(P<0.01),但与边缘组织无显著性差异。分化较好的胃腺癌与未分化癌间七种微量元素含量均无显著性差异。这些结果提示,胃癌组织中锌值的降低与铜/锌比值的升高可作为胃癌的辅助诊断指标,而且锌值的检测更具意义。但与分化程度无关。     

增强夜间视力的元素——锌

锌是人体及许多动植物的必需元素之一。成人体内含锌量约为 2 . 3ｇ ,为铁含量的一半 ,但比铜高几十倍。人体的一切器官和血液中都都含有锌。肝和视网膜内的锌含量特别高 ,肝脏中锌含量为 10× 10 - 6 ～ 2 0 0× 10 - 6 (10 - 6 即百分万分之一 ) ,视网膜内高达 50 0× 10 - 6 ～ 10 0 0 0× 10 - 6 。人和动物的精液中也含有大量锌。有趣的是 ,鱼类在产卵前 ,几乎把把身体中全部的锌转移到鱼卵中去。增强夜间视力的元素——锌     

714名0～6岁儿童头发中6种微量元素含量及水平分析

报道了南山区714名0～6岁儿童头发中锌、铜、铁、钙、镁和锰的含量，发锌79．88×10－6、发铜9．64×10－6、发铁31．36×10－6、发钙560．54×10－6、发镁为66．12×10－6、发锰为2．24×10－6，并对分析数据进行了医学统计分析，结果表明各年龄组间、性别间无显著性差异。     

半枝莲中铜,锰,锌的初级形态分析

按照微量元素初级形态分析要求,对抗癌中药半枝莲的原药、头煎、二煎、及其残渣、用0.45μm膜分离煎液所得的颗粒物及可溶态共7种样品中的铜、锰、锌进行测定。通过计算得到一系列形态分析参数。其中原药中微量元素含量Cu 18.56×10~(-6),Zn 149.4×10~(-6),Mn 218.8×10~(-6)。头煎提取率:Cu32.67％、Zn 43.69％、Mn 44.49％。二煎提取率:Cu 1.61％、Zn 16.13％、Mn 5.01％。     

毛细管电泳单脉冲伏安测定重金属铜铅锌镉

以毛细管为分离通道 ,在KNO3 缓冲溶液中 ,用表面镀汞膜的金微电极作为工作电极 ,采用单脉冲伏安法同时测定铜、锌、铅、镉含量 ,考察并优化了影响分离和检测的相关因素 :缓冲溶液pH、分离高压、脉冲上限和下限、脉冲宽度等。该法的最佳实验条件 :5mmol/LKNO3(pH6.0) ,分离高压20kV ,脉冲上限 -0.2V ,脉冲下限 -1.15V(vs.SCE) ,脉冲宽度500ms。结果表明 ,各峰面积与其离子浓度成线性关系 ,线性范围(μg/mL)分别为 :铜5.0×10-2～10.0;锌1.0×10-2～10.0 ;铅5.0×10-2～5.0 ;镉2.0×10-2～10.0。加标回收率在95%～110%之间。用该法较好地测定了水样中的重金属铜锌铅镉     

广州地区妊娠妇女锌、钙代谢状况调查

调查了31名早孕妇女的头发锌、钙含量,其中锌为(139.0±40.1)×10-6,钙为(1081±478)×10-6;中孕妇女37名,发锌为(142.4±25.2)×10-6,钙为(666.1±143.3)×10-6;而69名晚孕妇女头发锌含量为(140.9±25.0)×10-6,钙含量为(864.7±562.8)×10-6。对照组为非妊娠健康妇女,共41名,头发锌含量为(158.1±61.9)×10-6,钙含量为(1241±546)×10-6。结果显示,三期妊娠妇女的发锌、发钙含量均显著低于正常对照组。     

广州地区健康儿童及成人发硒含量调查

测定了广州地区52名健康儿童及72名健康成人的发硒含量。儿童平均年龄6.4±3.3岁,儿童男性发硒含量为(0.44±0.14)×10-6,女性为(0.40±0.15)×10-6。成人平均年龄53.3±14.7岁,成人男性发硒含量为(0.49±0.12)×10-6,女性为(0.51±0.12)×10-6。儿童及成人发硒含量男女之间不存在显著性差异,男性儿童与男性成人发硒含量不存在显著性差异,但女性儿童发硒含量显著低于女性成年人。     

微量元素锌与反复呼吸道感染的相关性

对28例反复呼吸道感染患儿(下称复感儿)及26例健康儿进行微量元素发锌测定。发现前者发锌平均值为(92.3±14.7)×10~(-6),后者为(132.5±21.5)×10~(-6),P<0.01,差异非常显著。对复感儿进行口服锌治疗,观察其疗效及治疗前后发锌变化。治疗前发锌平均值为(92.3±14.7)×10~(-6),治疗后为(137.5±20.2)×10~(-6),P<0.01差异非常显著。有效率达85.7％。故缺锌可能是复感儿患病的影响因素之一,锌治疗小儿反复呼吸道感染是十分必要的。     

ICP-AES测定铀污染土壤植物中铀的研究

采用电感耦合等离子体发射光谱(ICP-AES)对铀污染土壤植物中铀的测定方法进行了研究.在λU385.958 nm处,选择了仪器的最佳工作条件,考察了酸度和常见共存元素对测定的干扰情况,并且对比了干灰化消解和湿式消解对测定的影响.研究发现2%硝酸溶液为最佳介质,干扰离子对测定没有显著影响,干灰化消解比湿式消解得彻底.在选定条件下,方法检出限为0.18 mg·L-1,测定下限为0.61 mg·L-1,5.0000 mg·L-1的铀标准溶液的相对标准偏差RSD(n=10)为0.81%,方法回收率为96.2%～106.2%.该方法操作简单,快速.结果表明,用ICP-AES测定铀污染土壤植物样品中的铀是可行的.     

测定血清中Na 含量不确定度的评定

对血清中Na离子含量的测量不确定度进行评定。不确定度的来源主要包括Na离子标准工作液的配制过程、血清样品的定容消化制备、标准曲线拟合、钠离子各分量不确定度的合成等引入的不确定度计算出各分量的不确定度,通过合成得到测量结果的合成不确定度、扩展不确定度及测试结果的报告形式。     

Interpretation of inorganic arsenic metabolism in humans in the light of observations made in vitro and in vivo in the rat

The toxicity of inorganic trivalent arsenic for living organisms is reduced by in vivo methylation of the element. In man, this biotransformation leads to the synthesis of monomethylarsonic (MMA) and dimethylarsinic (DMA) acids, which are efficiently eliminated in urine along with the unchanged form (As_i). In order to document the methylation process in humans, the kinetics of As_i, MMA and DMA elimination were studied in volunteers given a single dose of one of these three arsenicals or repeated doses of As_i. The arsenic methylation efficiency was also assessed in subjects acutely intoxicated with arsenic trioxide (As₂O₃) and in patients with liver diseases. Several observations in humans can be explained by the properties of the enzymic systems involved in the methylation process which we have characterized in vitro and in vivo in rats as follows: (1) production of As_i metabolites is catalyzed by an enzymic system whose activity is highest in liver cytosol; (2) different enzymic activities, using the same methyl group donor (S-adenosylmethionine), lead to the production of mono- and di-methylated derivatives which are excreted in urine as MMA and DMA; (3) dimethylating activity is highly sensitive to inhibition by excess of inorganic arsenic; (4) reduced glutathione concentration in liver moderates the arsenic methylation process through several mechanisms, e.g. stimulation of the first methylation reaction leading to MMA, facilitation of As_i uptake by hepatocytes, stimulation of the biliary excretion of the element, reduction of pentavalent forms before methylation, and protection of a reducing environment in the cells necessary to maintain the activity of the enzymic systems.     

超临界流体萃取技术在提取中药挥发油中的应用

用超监介CO2流体萃取技术对多种中药挥发油的提取进行了综述,并将其与传统的水蒸馏法进行比较。结果表明,用超临界流体法不仅挥发油的收率高,而且提取时间也大大缩短。     

Assessment of performance of laboratories in determining acrylamide in crispbread

A proficiency testing round was undertaken to assess the performance of laboratories to measure acrylamide in a sample of crispbread. Retail samples of crispbread were ground to a fine powder and after thorough mixing were packed in 40 g units for distribution. Ten samples were selected at random and analyzed in duplicate for acrylamide by liquid chromatography/mass spectrometry (LC/MS). Standard statistical tests showed that the material was homogeneous for the purposes of proficiency testing. Test samples were distributed to 55 laboratories in 16 countries in Europe, North America, Australia, and the Middle East. The results were analyzed by standard proficiency testing statistical procedures, and laboratories were awarded z-scores on the basis of their reported results. Based on a target standard deviation (sigmap value) taken from the Horwitz equation, for a robust mean value of 1.2 mg/kg acrylamide, satisfactory results (z-score within +/- 2 for those between 0.8 and 1.6 mg/kg) were obtained by 86% of the 37 laboratories that returned results. Only 1 laboratory was unsatisfactory and 4 had questionable results. About equal numbers of laboratories used gas chromatography (GC)/MS and LC/MS procedures with about 25% using MS/MS and one using GC with electron capture detection. There was no evident trend in performance or bias in results. GC/MS and LC/MS data were evenly distributed across the population of laboratories reporting results.     

茶叶中高氯酸盐检测方法研究进展

茶叶中新型污染物高氯酸盐在近年来受到越来越多的关注,相应的检测技术也在不断加强.参考国内外文献,综述了茶叶中高氯酸盐的检测方法.目前,茶叶中高氯酸盐的检测方法主要有离子色谱法（IC）、离子色谱-质谱法（IC-MS）和高效液相色谱-串联质谱法（LC-MS-MS）.比较了不同检测方法的局限性和优越性,重点比较了高效液相色谱-串联质谱法不同前处理方法、净化小柱和检测条件的优劣,对茶叶高氯酸盐检测技术的发展和研究进行了展望,为检测茶叶中高氯酸盐的新材料研发和检测新标准的建立提供理论依据.     

成都西部金马地区土壤微量元素特征研究

对成都平原西部金马镇深层土壤取样分析,研究了具有指示意义的几种微量元素富集情况,揭示了土壤原生地球化学环境质量;通过异常信息的筛选,分析了各元素异常反映的地球化学及地质信息.     

Effect of vibration in processes of structure formation in polymers

It was shown that the strength characteristics of the samples produced from thermoplastics (low density polyethylene, polyamide 6, Armamid, and polyethylene terephthalate) increase as a result of short vibration treating with a frequency close to that of natural vibrations of the structural elements.     

Use of matrix-modifiers in atomic-absorption determination of chromium in argillites

The direct atomic-absorption determination of chromium in argillites, without preliminary concentration and separation, has been studied. A map of selective flame zones for determining Cr in argillites has been designed. An express method for determining Cr in Estonian argillites has been suggested.