保健食品中铅、砷、汞微波消解前处理方法的研究

目的 应用微波消解前处理测定保健食品中铅、砷、汞的含量。方法 用微波溶样系统对保健食品进行消解，消解过的样品可用于石墨炉的原子吸收光谱仪和原子荧光光谱仪同时测定保健食品中的铅、砷、汞的含量。结果 本方法测定铅、砷、汞的检出限分别0．28μg／kg、0．007mg／kg和0．10μg/kg；回收率分别为88．5％～106．0％、85．0％～106．0％、和88．2％～96．7％；测定线性范围分别为0～100．0 ng／ml、0～200．0,ng／ml和0～60．0μg／L。结论 该方法简便、快速，灵敏度、精密度、准确度较好，适合保健食品的快速消解及微量金属污染物的定量分析。     

微波消解同时测定农产品中铅、镉、汞

目的:建立一种适合同时测定农产品中铅,汞,镉的样品前处理方法。方法:采用微波消解方法处理样品,样品消化液经赶酸后定容,分别用来测定汞和铅、镉。结果:测定铅,镉,汞方法的线性范围分别为:0.0μg/L～20μg/L,0.0μg/L～2μg/L,0.0μg/L～5μg/L;相关系数分别为:0.9979,0.9978,0.9988;回收率分别为:95.8%～103%,95.1%～104%,98.4%～110.6%;方法的检测限分别为0.012μg/L,0.009μg/L,0.0027μg/L。结论:该方法精密度好,准确度高,快速简单,能够很好地满足农产品中铅,汞,镉含量的测定要求。     

微波消解-石墨炉原子吸收光谱法测定土壤中铅和镉

[目的]建立微波消解-石墨炉原子吸收光谱测定土壤中铅和镉的分析方法。[方法]土壤样品研磨过100目筛,用硝酸-氢氟酸-过氧化氢混合消解液微波消解后,石墨炉原子吸收光谱测定。[结果]铅浓度为5.0~40.0μg/L、镉浓度为0.20~2.00μg/L时,石墨炉原子吸收光谱测定土壤中铅和镉的方法线性良好,相关系数均为0.9999。铅和镉的方法定量检出限分别为5.0、0.040mg/kg。加标回收率为90.0%~110.0%,相对标准偏差为4.1%~6.9%,标样的测定结果在不确定度范围内。[结论]该方法简便、快速,基体干扰少,结果准确,适用于土壤中铅、镉含量的测定。     

微波消解-石墨炉原子吸收法测定滩涂中的铅和镉

目的:建立滩涂中铅和镉的微波消解-石墨炉原子吸收光谱测定方法。方法:以磷酸二氢铵-硝酸镁作基体改进剂,采用硝酸-氢氟酸进行微波消解,利用塞曼扣背景,石墨炉原子吸收法测定滩涂中的铅和镉含量。结果:铅和镉分别在2.0μg/L～50.0μg/L和0.2μg/L～5.0μg/L范围内具有良好的线性,相关系数大于0.999,加标回收率为90%～103%,RSD均小于5.0%。结论:建立的方法具有简便、灵敏、准确的特点,适合于高盐滩涂中铅镉的测定。     

连续测定化妆品中微量汞、砷、铅的方法研究

目的：建立一种快速消解法消化样品并能连续测定化妆品中汞、砷、铅的方法。方法：应用微波消解法消化样品，氢化物-原子荧光光谱法连续测定化妆品同一试样中汞、砷、铅。结果：在经过优化的实验条件下。汞、砷、铅的检出限分别为0．005、0．08、0．2μg／L；本方法取样0．5g，稀释62．5倍，汞、砷、铅的最低检测浓度分别为0．6、10．0、30．6μg／kg，测定化妆品中汞、砷、铅的荧光强度与其浓度的线性范围分别为0-2．5、0-50和0-50μg/L。得到3种元素的回收率在90％-102％之间，相对标准偏差小于或等于2％，方法操作更为简便、快速、准确、灵敏度高。结论：化妆品中微量汞、砷、铅可以用微波消解-氢化物原子荧光光谱法连续测定。     

中药材中重金属的测定

采用微波消解样品、石墨炉原子吸收分光光度法测定植物药材中铅和镉 ,冷原子吸收分光光度法测定植物药材中的汞。用此方法测定了美国NBS15 70标准参考物质菠菜粉 ,以及 2 3种 2 6 4份植物药材。铅、镉、汞方法的平均回收率分别为 95 8%、97 5 %、99 2 % ;检出限 (LOD)分别为 0 0 0 6mg kg、0 2 0 8μg kg、0 0 2 6 μg kg;定量限 (LOQ)分别为 0 0 19mg kg、0 6 94μg kg、0 0 87μg kg。此方法同样适用于食物样品中铅、镉和汞的检测工作     

微波消解-石墨炉原子吸收法测定小海鲜产品中的铅和镉

目的:建立小海鲜产品中铅和镉的微波消解-石墨炉原子吸收光谱测定方法。方法:以磷酸二氢铵-硝酸镁作基体改进剂,采用硝酸进行微波消解,利用塞曼扣背景,石墨炉原子吸收法测定小海鲜产品中的铅和镉含量。结果:铅和镉分别在2.0μg/L～50.0μg/L和0.2μg/L～5.0μg/L范围内具有良好的线性,相关系数大于0.999,铅镉的的最低检出限为5.4μg/kg湿重和0.31μg/kg湿重,加标回收率为90.0%～102.0%,RSD均小于5.0%,采用本法对国家标准物质贻贝GBW08571进行测定,经t检验(P>0.05),测定结果与标准值无显著性差异。结论:建立的方法具有简便、灵敏、准确的特点,适合于高盐海产品中铅镉的测定。     

微波消解等离子体质谱法测定各类食品中痕量汞、镉、铅、砷准确性探讨

目的 建立微波消解-电感耦合等离子体质谱法（ICP-MS）准确测定各类食品中痕量汞、镉、铅、砷的分析方法。方法 采用微波消解法处理样品,ICP-MS测定以^72Ge、^103Rh、^185Re作为内标消除非质谱干扰,八极杆碰撞池（ORS^3）消除质谱干扰。结果 采用本方法测定汞、镉、铅、砷的定量限分别为0.05、0.05、0.40、0.40μg/L;在定量限附近测定的回收率和相对标准偏差分别为：100.0%、90.0%、96.0%、112.0%和7.6%、8.0%、11.8%、6.2%。结论 采用ICP-MS法准确测定食品中痕量有害元素的关键点及控制措施,适用于食品安全风险监测大批量样品的分析。     

微波消解-石墨炉原子吸收光谱法测定蔬菜中微量铅和镉

目的：建立了微波消解技术进行样品前处理，结合石墨炉原子吸收测定蔬菜中重金属元素铅和镉的方法。方法：在蔬菜试样中加入适量硝酸及过氧化氢，进行微波消解。消解液中的铅和镉用石墨炉原子吸收分光光度计直接测定。为提高灰化温度，有效消除基体干扰，选用磷酸二氢铵作基体改进剂。结果：铅和镉的检出限分别为1．83μg／kg和0．394μg／kg。样品测定回收率分别为94％～109％和96％～108％，RSD分别为2．8％～6．3％和2．4％～6．6％。结论：所得分析结果与常规湿式消解比较，具有更好的准确度和精密度。此方法还具有操作简单、快速、减少污染和损失等优点。     

石墨炉原子吸收法测定蔬菜中铅和镉

目的：建立蔬菜中微量铅和镉的测定方法。方法：采用微波消解样品，石墨炉原子吸收法测定蔬菜中铅和镉。结果：铅：在0～100μg/L范围内，r=0．999l。镉：在0～40μg/L范围内，r=0．9995。铅的特征量为13pg，检出限为5μg/kg，镉的特征量为0．5pg，检出限为0．1μg/kg。相对标准偏差：铅：4．8％，镉：4．6％，茶叶样品加标回收率分别为铅：89％～104．8％，镉：91．9％～102．6％。结论：石墨炉原子吸收法测定蔬菜中铅和镉，是一种快速、灵敏、准确的分析方法。     

Heat-related illnesses, deaths, and risk factors--Cincinnati and Dayton, Ohio, 1999, and United States, 1979-1997

During the summer of 1999, a heat wave occurred in the midwestern and eastern United States. This period of hot and humid weather persisted from July 12 through August 1, 1999, and caused or contributed to 22 deaths among persons residing in Cincinnati (18 deaths) and Dayton (four deaths). A CDC survey of 24 U.S. metropolitan areas indicated that Ohio recorded some of the highest rates for heat-related deaths during the 1999 heat wave, with Cincinnati reporting 21 per million and Dayton reporting seven per million (CDC, unpublished data, 1999). This report describes four heat-related deaths representative of those that occurred in Cincinnati or Dayton during the 1999 heat wave, summarizes heat-related deaths in the United States during 1979-1997, describes risk factors associated with heat-related illness and death, and recommends preventive measures.     

International standards and international reference preparations: amphotericin B, vancomycin, capreomycin, cefalotin, demethylchlortetracycline, gentamycin, gramicidin S, kanamycin and kanamycin B, lincomycin, lymecycline, methacycline, paromomycin, rifamycin SV, ristocetin and ristocetin B, spiramycin, and triacetyloleandomycin

Each of the preparations described here was obtained and evaluated at the request of a WHO Expert Committee on Biological Standardization. Unless otherwise stated, a standard procedure was used to distribute the material into individual ampoules. The procedure was as follows. Upon receipt by the National Institute for Medical Research (NIMR), London, materials were stored temporarily in the dark at a temperature of -10°C or lower, and protected from moisture. At a convenient time they were brought back to room temperature, mixed, and distributed into individual neutral glass ampoules so that each ampoule contained 50-100 mg of powder. If it was known that the material was light-sensitive non-actinic glass ampoules were used. After exhaustive drying in vacuum over phosphorus(V) oxide, the ampoules were either constricted (up to 1963) or fitted with capillary leak plugs, dried for a further period under the same conditions, filled with dry nitrogen, and sealed by fusion of the glass. The total drying period varied from 8 to 38 days according to the nature of the material. After they had been tested for leaks, the ampoules were stored in the dark at -20°C.     

Zinc, copper, and magnesium and risks for all-cause, cancer, and cardiovascular mortality

BACKGROUND: Experimental data suggest that zinc, copper, and magnesium are involved in carcinogenesis and atherogenesis. Few longitudinal studies have related these minerals to cancer or cardiovascular disease mortality in a population. METHODS: Data from the Paris Prospective Study 2, a cohort of 4035 men age 30-60 years at baseline, were used to assess the association between serum zinc, copper, and magnesium and all-cause, cancer, and cardiovascular disease mortality. Serum mineral values measured at baseline were divided into quartiles and classified into low (1st quartile, referent group), medium (2nd-3rd quartiles), and high (4th quartile) values. During 18-year follow up, 339 deaths occurred, 176 as a result of cancer and 56 of cardiovascular origin. Relative risks (RRs) for each element were inferred using Cox's proportional hazard model after controlling for various potential confounders. RESULTS: High copper values (4th quartile) were associated with a 50% increase in RRs for all-cause deaths (RR = 1.5; 95% confidence interval = 1.1-2.1), a 40% increase for cancer mortality (1.4; 0.9-2.2), and a 30% increase for cardiovascular mortality (1.3; 0.6-2.8) compared with low values (1st quartile). High magnesium values were negatively related to mortality with a 40% decrease in RR for all-cause (0.6; 0.4-0.8) and cardiovascular deaths (0.6; 0.2-1.2) and by 50% for cancer deaths (0.5; 0.3-0.8). Additionally, subjects with a combination of low zinc and high copper values had synergistically increased all-cause (2.6; 1.4-5.0) and cancer (2.7; 1.0-7.3) mortality risks. Similarly, combined low zinc and high magnesium values were associated with decreased all-cause (0.2; 0.1-0.5) and cancer (0.2; 0.1-0.8) mortality risks. CONCLUSIONS: High serum copper, low serum magnesium, and concomitance of low serum zinc with high serum copper or low serum magnesium contribute to an increased mortality risk in middle-aged men.     

Psychological distress, gender, and health lifestyles in Belarus, Kazakhstan, Russia, and Ukraine

This paper examines the relationship between psychological distress, gender, and health lifestyles in Belarus, Kazakhstan, Russia, and Ukraine. These countries have been subjected to highly stressful and extensive social change associated with the transition out of communism. Data were collected by face-to-face interviews (n = 10,406) in November 2001. Distress was measured by 12 psychological distress symptoms. Health lifestyles focused on measures of alcohol consumption, smoking and diet. We found that females carried a much heavier burden of psychological distress than males, but this distress did not translate into greater alcohol consumption and smoking for these women or for men. The greatest influence of distress on health lifestyle practices was on daily diets in that both less distressed females and males consumed a more balanced diet than more distressed persons. Our findings suggest that it is the normative demands of a particular lifestyle, rather than distress, that principally shapes the pattern of heavy male drinking. This is an important finding as some sources indicate heavy drinking is largely responsible for the health crisis in the former socialist states.     

Dietary sodium, calcium, and potassium, and blood pressure

The cross-sectional association of systolic blood pressure with dietary sodium, calcium, and potassium, as estimated from dietary histories, was investigated by multiple regression analysis of data gathered in the Netherlands in the early 1950s in a general health examination of 2,291 middle-aged civil servants and spouses of civil servants. A statistically significant negative trend with systolic blood pressure was seen for calcium intake in both males and females, even after adjustments for covariates. For sodium and potassium intake, the observed negative trends were not significant after multivariate analyses. In addition, no consistent associations were found between diastolic blood pressure and the micronutrients after multivariate analyses, except for a significant negative association with calcium intake in females. In this study population, blood pressure was a strong independent risk factor of total mortality: 15- and 25-year mortality was about twice as high for hypertensives (greater than or equal to 160 mmHg) as for normotensives (less than 160 mmHg). These findings support the conclusion in recent epidemiologic studies that higher intakes of calcium are associated with lower systolic blood pressure, and they extend the evidence to an earlier time period.     

Professional and Consumer Publications, Programs, Audiovisuals, and Software

Books, curricula, audiovisuals, and other resources that nutrition professionals may use for reference, continuing education, or in a formal or informal education setting are designated “professional.” Books, handouts, diet plans, and other resources specified by authors as being written for general audiences are categorized as “consumer.” Inclusion of any material in this section does not imply endorsement by the Society for Nutrition Education. Evaluative comments contained in the reviews reflect the views of the authors. Prices quoted are those provided by the publishers at the time materials were submitted. They may no longer be current when the review is published.     

Professional and Consumer Publications, Programs, Audiovisuals, and Software

Books, curricula, audiovisuals, and other resources that nutrition professionals may use for reference, continuing education, or in a formal or informal education setting are designated “professional.” Books, handouts, diet plans, and other resources specified by authors as being written for general audiences are categorized as “consumer.” Inclusion of any material in this section does not imply endorsement by the Society for Nutrition Education. Evaluative comments contained in the reviews reflect the views of the authors. Prices quoted are those provided by the publishers at the time materials were submitted. They may no longer be current when the review is published.