阳极溶出伏安法同时测定罐头食品中锌、镉、锡、铅和铜的含量

本文研究了用1.5次微分阳极溶出伏安法,在盐酸-甲醇底液中,以棒状银基汞膜电极为工作电极,同时测定罐头食品中锌、镉、锡、铅和铜的方法。在0.24M盐酸-甲醇底液中五种元素的阳极溶出峰电位分别为:锌-1.05V,镉0.74V、锡-0.55V,铅-0.44V,铜-0.25V(相对SCE)。镉、锡、铅、铜的浓度在20～500ng/ml范围、锌浓度在0.2～4μg/ml范围与峰高呈线性关系。罐头食品用混合酸消化后取稀释液测定,果汁可用底液稀释直接测定。样品测定精密度为6.7～8.0％,回收率为91.2～107％。     

合成色素及铅砷铜的极谱测定法

合成色素在乙二胺—硫氰酸钾的不同 pH 溶液中有良好的极谱波。其中 pH13时笕莱红、日落黄、胭脂红分别在-0.45,-0.49,-0.57V(vs.SCE,下同)出峰,PH10时柠檬黄在-0.49V 出峰,亮蓝在 pH3时于-0.38V 出峰,线性范围为5—100μg。在此底液基础上分别加入碘化钾、亚膏酸盐,可连续测定铜(-3.2V)、铅(-0.43V)、砷(-0.49V),铜、铅在0.2～10.0μg 范围、砷在0.1～4μg 范围内与峰电流呈线性关系。     

铋膜电极微分电位溶出法测定食品中铅和锌

目的：建立一种食品中铅和锌的快速绿色微分电位溶出分析。方法：以镀铋膜电极代替汞膜电极为工作电极进行同位镀铋微分电位溶出分析，依据溶出峰值（dt／dE）与被测离子浓度成正比的关系定量。结果：在HAc—NaAc介质中，铅、锌可在镀铋膜电极上得到灵敏的微分电位溶出峰，峰电位分别为-0．55V及-1．10V，检出限铅为0．02μg/25ml，锌为0．03μg/25ml，建立了测定食品中痕量铅、锌的铋膜电极微分电位溶出法。结论：方法无污染，灵敏、简便，是种快速绿色的分析方法。     

铅镉示波极谱法测定

目的：建立铅镉示波极谱测定方法。方法：用示波极谱法测定食品中的铅、镉。结果：铅、镉离子在盐酸-碘化钾-酒石酸钾钠-抗坏血酸底液中有一尖锐、灵敏的络合吸附波，其峰电位分为-0．54V、-0．71V（vs．SCE），二阶导数峰电流与铅、镉浓度在0-0．4μg／ml范围内呈良好线性关系，相关系数均〉0．999。结论：该体系实际应用于食品卫生、水质卫生、职业病、铅烟等领域，具有波形好、灵敏度高、结果准确等优点。     

螺旋藻中锌、铜、锰的电感耦合等离子体质谱测定法

为探讨螺旋藻样品中锌、铜、锰的电感耦合等离子体质谱测定法,优化仪器工作参数,用内标溶液校正基体效应干扰。结果显示线性范围均为0.1～500μg/L,均r0.999,锌检出限为5.0μg/L,回收率90.1%～105.7%;铜检出限为1.1μg/L,回收率为95.8%～101.5%;锰检出限为0.90μg/L,回收率93.2%～100.1%。该方法灵敏快速、简便准确,适用于螺旋藻样品中锌、铜、锰的测定。     

考核水样中19种微量元素的ICP-AES同时测定法

目的建立电感耦合等离子体-原子发射光谱法同时测定考核水样中铝、锑、砷、钡、铍、硼、镉、铬、铜、铁、铅、锰、钼、镍、硒、银、铊、钒、锌共19种微量元素含量的分析方法。方法优化了仪器条件,提高了信噪比,避免了谱线干扰,水样按考核要求用0.5%硝酸稀释后直接进样分析。结果 19种微量浓度在0～2.0μg/ml范围内呈良好线性关系,方法最低检出限在0.3～6.3μg/L,回收率为89.0%～105.1%,相对标准偏差(RSD)为0.18%～4.30%。结论该方法是一种快速,灵敏,准确的分析方法,可用于考核水样中19种微量元素的同时测定。     

黔南州部分7～14岁学生头发微量元素检测分析

目的了解黔南州7～14岁学生头发微量元素含量情况,为进一步调节学生善食,控制学生微量元素缺乏和过多引起疾病提供科学依据。方法用火焰原子吸收法测定锰、锌、铜、铁,用无火焰(石墨炉)原子吸收法测定铅。结果黔南州7～14岁学生头发锰均值4.92μg/g,头发锰﹤4.0μg/g人数占53.3%,4.0～4.95μg/g人数占12.3%,﹥4.95人数占34.4%;头发锌均数74.85μg/g,绝大部分检测值均低于110μg/g下限;头发铜均数11.38μg/g,﹤9μg/g人数占16.4%,9～30μg/g人数占83.1%,﹥30μg/g占0.5%;头发铁均数59.41μg/g,﹤25μg/g人数占1.5%,25～60μg/g人数占60.0%,﹥60μg/g人数占38.5%;头发铅均数4.38μg/g,﹤10μg/g人数占94.4%,﹥10μg/g人数占5.6%。结论绝大部分学生要补充锌的摄入,锰、铜、铁要根据每个学生不同情况增加或减少摄入,使学生体内的元素达到平衡,铅﹥10μg/g的极少数学生要防止铅的摄入,才会有益健康。     

“单扫描极谱法测定食品中铅”国家标准方法研制验证报告

[目的]验证国标--单扫描极谱法测定食品中铅的可行性.[方法]运用GB/T5009.1-1996附录A和国家示波极谱议计量检定规程,对其线性关系及范围、检出限、精密度和准确度、稳定性进行验证.[结果]线性范围0.50～20μg铅,相关系数r=0.9999,检出限0.06μg铅,方法精密度0.32%,样品精密度5.1%～10.6%,回收率82.4%～108%,[结论]该法可适用于食品中铅含量测定.     

催化极谱法测定车间空气中四乙基铅

本文报告了一种测定车间空气中四乙基铅的新方法。以活性碳采集样品,用硝酸消解浸出铅,然后在6％乙醇—0.02mol/L钒(IV)—0.1％抗坏血酸—1％碘化钾—0.04mol/L盐酸底液中测定铅的极谱催化波。峰电位为-0.5 V(对饱和甘汞电极),波高与铅浓度在0.005～2μgml~(-1)范围内成直线关系。方法灵敏度高(检测限为0.078μg/10ml四乙基铅),精密度和准确度较好,没有干扰。仪器便宜,操作简单,适宜推广应用。     

微机极谱仪测定食品中微量铬

铬的极谱催化波已有许多报道。铬的2，2’-联吡啶催化波的最大的优点是铬与亚硝酸钠形成互催化波，与亚硝酸钠极谱波完全分离。应用此催化波测定食品中微量铬，具有灵敏，重现，峰半宽小等优点，检测下限0．2μg／L，线性范围0．2～4μg／L，相对标准偏差为4．32％。锌、锰、铅、铜、镉不干扰测量，取得了满意结果。     

Risk,Efficacy, and Seeking of General,Breast, and Prostate Cancer Information

The authors investigated the independent and interactive effects of perceived risk and perceived efficacy on seeking of general, breast, and prostate cancer information. Analysis of the 2003 Health Information National Trend Survey indicates that perceived absolute risk and perceived response efficacy have generally independent—rather than interactive—effects on cancer information seeking. The influence of perceived absolute risk on prostate cancer information seeking appears to be moderated by perceived relative risk. When perceived relative risk is low, perceived absolute risk has no effect on prostate cancer information seeking; when perceived relative risk is high, perceived absolute risk exerts a significant positive influence on prostate cancer information seeking. The authors discuss the theoretical and practical implications.     

Risk, efficacy, and seeking of general, breast, and prostate cancer information

The authors investigated the independent and interactive effects of perceived risk and perceived efficacy on seeking of general, breast, and prostate cancer information. Analysis of the 2003 Health Information National Trend Survey indicates that perceived absolute risk and perceived response efficacy have generally independent-rather than interactive-effects on cancer information seeking. The influence of perceived absolute risk on prostate cancer information seeking appears to be moderated by perceived relative risk. When perceived relative risk is low, perceived absolute risk has no effect on prostate cancer information seeking; when perceived relative risk is high, perceived absolute risk exerts a significant positive influence on prostate cancer information seeking. The authors discuss the theoretical and practical implications.     

Bioaccumulation,metabolism, and effects of DDT,fenitrothion, and chlorpyrifos onSaccharomyces cerevisiae

Saccharomyces cerevisiae accumulated DDT, fenitrothion, and chlorpyrifos rapidly from yeast glucose medium. The maximum concentrations of DDT, fenitrothion, and chlorpyrifos accumulated were 8,253, 18,960 and 11,579 g/g (dry wt), respectively. The pattern of accumulation was similar for all insecticides. The bioconcentration factor was inversely proportional to insecticide solubilities.Saccharomyces metabolized the three insecticides, but only two metabolites of DDT (DDD and DDE) were identified. Protoplast cultures were more sensitive to DDT and fenitrothion compared to normal cultures but were less sensitive to chlorpyrifos. Both the normal and protoplast cultures recovered from the toxic effect after 24 hr.     

Water,sanitation, and hygiene in schools: Status and implications of low coverage in Ethiopia,Kenya, Mozambique,Rwanda, Uganda,and Zambia

Adequate access to water, sanitation, and hygiene (WaSH) in schools impacts health, educational outcomes, and gender disparities. Little multi-country research has been published on WaSH in rural schools in Sub-Saharan Africa. In this multi-national cross-sectional WaSH study, we document WaSH access, continuity, quality, quantity, and reliability in 2270 schools that were randomly sampled in rural regions of six Sub-Saharan African countries: Ethiopia, Kenya, Mozambique, Rwanda, Uganda, and Zambia. Data collection included: school WaSH surveys containing internationally established WaSH indicators, direct observation, and field- and laboratory-based microbiological water quality testing. We found 1% of rural schools in Ethiopia and Mozambique to 23% of rural schools in Rwanda had improved water sources on premises, improved sanitation, and water and soap for handwashing. Fewer than 23% of rural schools in the six countries studied met the World Health Organization’s recommended student-to-latrine ratios for boys and for girls. Fewer than 20% were observed to have at least four of five recommended menstrual hygiene services (separate-sex latrines with doors and locks, water for use, waste bin). The low access to safe and adequate WaSH services in rural schools suggest opportunities for WaSH interventions that could have substantive impact on health, education, and gender disparities.     

Analysis of protein amino acids,non-protein amino acids and metabolites,dietary protein,glucose, fructose,sucrose, phenolic,and flavonoid content and antioxidative properties of potato tubers,peels, and cortexes (pulps)

The composition and antioxidative activity of whole potato tubers from five Korean cultivars, three peels from one cultivar, and eight pulps (cortexes) after peeling from six different cultivars were evaluated. Whole tubers were sectioned into three parts followed by analysis of the peels and pulps of each part. The following characteristics were determined: the dimensions and water content of whole tubers; nutritional protein content consisting of protein and free amino acids by an automated Kjeldahl nitrogen assay; free non-protein amino acids, metabolites, and fructose, glucose, and sucrose content by HPLC; phenolic compounds by HPLC and LC/MS; total phenolics and flavonoids by colorimetry; and antioxidative properties by ABTS, DPPH, and FRAP assays. The results demonstrate differences and similarities in the content of nutritional and bioactive compounds and in their bioactivities from whole potatoes, peels, and pulps. The present study reports for the first time the analysis of multiple potato nutrients and bioactive components as well the antioxidative properties of whole potatoes, peels, and pulps derived from the same tubers. The described methods are expected to facilitate the analysis of commercial and newly-developed potato cultivars, peels, and pulps and relate their composition and antioxidative activities to their reported nutritional, health-promoting, and industrial properties.     

Knowledge, attitudes, and practices related to treatment and prevention of cholera, Haiti, 2010

In response to the recent cholera outbreak, a public health response targeted high-risk communities, including resource-poor communities in Port-au-Prince, Haiti. A survey covering knowledge and practices indicated that hygiene messages were received and induced behavior change, specifically related to water treatment practices. Self-reported household water treatment increased from 30.3% to 73.9%.