火焰原子吸收法快速测定味精中铅和锌

味精中铅、锌按以往双硫腙法需分别测定 ,不仅工作量大 ,费时 ,而且条件难以控制。本法在ｐＨ8 0时 ,在10 0ｍｌ消解提取瓶中以双硫腙醋酸丁酯提取 ,然后用火焰原子吸收法同时测定铅和锌 ,现介绍如下。材料与方法1.原理 :样品中铅和锌在一定ｐＨ条件下与双硫腙络合 ,经醋酸丁酯萃取后导入火焰原子吸收光谱仪中 ,火焰原子化后吸收特定波长共振线 ,其吸收量与被测元素量成正比 ,与标准系列比较定量。2 .仪器 :日本岛津ＡＡ 6 10 5型原子吸收分光光度计 ;Ｕ 12 5ＭＮ型记录仪 10 0ｍｖ ;日产ＨＴＶ ,Ｌ2 33 型铅 ,锌空心阴极灯泡 ;日本ＡＤ公司…     

双硫腙分光光度法测定水中微量锌

目的　进一步验证双硫腙水相分光光度法测定水中微量锌的可靠性和适用性。方法　应用双硫腙水相分光光度法对锌合成密码水样和锌标准物质进行测定 ,同时与国标法进行实验对比。结果　两种方法测定锌标准物质的相对标准偏差分别为 0 7%和 4 2 % ,差异无显著性 (P >0 0 5 )。双硫腙水相分光光度法测定锌合成密码水样的相对标准偏差为 1 1% ,相对误差为 - 2 4 %。结论　双硫腙水相分光光度法能够准确测定合成密码水样和锌标准物质 ,是一种操作更加简便、快捷、准确、环保、低成本的新方法。     

水中锌测定方法的改进

水中锌的测定方法有原子吸收分光光度法、双硫腙分光光度法。双硫腙分光光度法由于设备简单 ,特别适用于基层实验室。但该法操作复杂、繁锁。作者改用甲基药红指示剂 ,采用一次性萃取法测定水中锌。该方法操作简便、快速、稳定 ,结果满意。现报告于下。1　材料与方法1.1　仪器与试剂　采用 752 C紫外分光光度计。 1锌标准液 1ml=1.0 0 μg锌应用液。 2双硫腙应用液吸光度 0 .4 (波长 53 5nm,1cm比色杯 )。 3乙酸 -乙酸钠缓冲液 ( p H4 .7)。 4 2 5%硫代硫酸钠溶液。 50 .2 %甲基橙指示剂。 6 1+1氨水。1.2　操作　按 GB5750 - 85双硫腙分…     

介绍一种简便、快速尿汞测定方法——双硫腙湿热消化法

前言目前国内尿汞测定法大部分为双硫腙法和蛋白汞法。双硫腙法又可分为热消化法、冷消化法、蒸馏法、酸硷中和法等等。我们从1962年以来曾采用过热消化、冷消化、蛋白汞等方法进行尿汞定量。在实践工作中我们体会到蛋白汞法对于尿汞测定不但灵敏度、回收率均低,而且费时间、操作过程繁琐,很不适应汞中毒防治的需要。双硫腙和许多金属离子进行络合反应时非常灵敏,有些方面甚致超过光谱分析,所以双硫腙法测定尿汞又带来某些困难,尤其象热消化法、蒸馏法等,需要回流冷凝等装置,这些装置均需严格的净化处理,操作时还需要较大量电力,冷却水等,因此,应用热消化法、蒸馏法进行现场测定或者是大量人员体检时的尿汞测定是有一定困难的。冷消化法消化时间太长,临床应用也受到一定限制。鉴于上述情况,我们实验和采用了双硫腙湿热消化法。该法测定尿汞简便、快速,测定结果比较稳定。测定过程的全部反应均在同一比色管内完成,该法所用仪器设备简单,适合临床检验应用,尤其适合现场尿汞测定。实验数据简介:     

塞曼恒温平台涂钼石墨炉原子吸收直接测定尿中铅,镉

铅、镉对人体健康的影响是众所周知的,迄今为止,尿铅、尿镉的浓度仍是环境评价、职业中毒的主要指标之一。以往尿铅、尿镉的测定多采用双硫腙比色法和火焰原子吸收法。其灵敏度都较低,操作繁杂费时。石墨炉原子吸收法具有方法简单、灵敏、快速、可靠的优点。但直接测定尿中铅和镉,复杂多变     

驱铅病人尿中铅含量的原子吸收法测定

尿铅的测定目前普遍采用冷消化—双硫腙比色法、热消化—双硫腙比色法和阳极溶出伏安法。这些方法对于一般的晨尿类样品的铅含量的测定具有灵敏度高和检测限低等优点。但是用这些方法来测定驱铅病人尿中的铅含量时,常常因样品中铅的浓度太高,超出了工作曲线的线性范围,难以准确计量,可能引起了较大的测量误差。考虑到火焰原子分光光度法的测定铅的线性范围较宽,笔者用它直接进样测定驱铅尿样中铅含量,具有快速、操作简便、结果准确、省时省力等优点。1 实验部分     

极谱法与原子吸收法测定尿铅的比较

测定尿铅的方法较多,常用的有双硫腙比色法,石墨炉无焰原子吸收法(简称GFAAS),示波极谱催化法(简称JP法),示波极谱催化法与经典的双硫腙比色法测定尿铅已作了比较,本文就示波极谱催化法与石墨炉无焰原子吸收法测定尿铅作全面比较,报道如下: 1 仪器与试剂 1.1 仪器:JP—Ⅱ型示波极谱仪;日立170—50A原子吸收分光光度计。 1.2 试剂:分别同方法。     

分光光度法测定锌盐泡制皮蛋中微量锌

本文着重介绍双硫腙比色法测定无铅皮蛋中的锌以及讨论了用锌盐代替铅盐泡制皮蛋的重要意义。选用的方法精密度高 ,且比较灵敏 ,适于皮蛋中锌的测定。现报告如下。1　实验部分1 1　试剂与仪器　所用试剂均为分析纯 ,无锌水 :用全玻璃容器重新蒸馏蒸馏水 ;0 0 1%双硫腙四氯化碳溶液 (10 0 μg/ml) ;2 5 %硫代硫酸钠溶液(pH4 0～ 5 5 ) ;锌标准溶液 (1μg/ml) :精密称取锌粒 0 10 0 0 g ,溶解于 10ml 2N盐酸中 ,加重蒸馏水稀释到 10 0 0ml,配成 10 0 μg/ml的贮备液 (贮存瓶事先用浓硝酸处理后备用 ) ,精密吸取贮备液 1ml,用重蒸馏水稀释…     

问题解答

[问]我国测定尿汞的方法有哪几种?其正常值是多少?以那几种较为实用? [答]目前我国已经报告的尿汞测定方法有:双硫腙法、蛋白沉淀法、离子交换层析法、无火焰原子吸收法和仪器快速测定法(用590型或732型汞蒸气测定仪)等方法。其中双硫腙法又分为蒸馏法、冷消化法、热消化法和酸碱中和等4种消化方法。     

双硫腙分光光度法测定水中锌方法的改进

锌是人类大量使用的金属.工业废水的污染和使用镀锌水管,都可能给水体带来污染,影响水体的性质.危害人体健康.因此锌的测定是各类水质监测的一项重要指标.水中锌的测定常采用火焰原子吸收光谱法和双硫腙比色法.光谱法仪器昂贵,对基层实验室还未能普及.双硫腙比色法仍然为较常用的经典方法.但笔者在实际工作中发现,由于该法干扰因素较多,标准曲线的线性关系较差,回归方程相关系数很难达到0.9990以上的要求,测定结果误差较大.因此本文尝试在不改变所用试剂的基础上,对提取方法加以改进,取得满意的效果.现将实验结果报告如下,以供参考.     

Trends in meningococcal disease in Italy in 1988

Meningococcal disease in Italy decreased 15% in 1988 from the previous year (290 vs. 342 cases). The decline was particularly evident in military cases (1.7/100,000 in 1988 vs. 5/100,000 in 1987) reflecting the full coverage of bivalent serogroup (A + C) meningococcal polysaccaride vaccine in army recruits, achieved since January 1988. The highest proportion of cases was seen in people older than 25 years of age (25%). Serogroup C constituted 60% of the isolates, while 19% belonged to serogroup B. The proportion of strains resistant to sulphonamides was 45%, while 15% were resistant to Minocycline and none to Rifampin. Out of the five military cases, only one (due to serogroup C) was attributable to the vaccine failure. A single coprimary case, but no secondary cases occurred among civilians. These findings are consistent with the trends reported in Italy in the previous years.     

Benzene in blood and phenol in urine in monitoring benzene exposure in industry

Determinations of benzene concentration in blood and of phenol in urine were made by head-space gas chromatography techniques on samples taken near the end of the work day from two groups of workers potentially exposed to low levels of benzene in the work-place atmosphere. Preliminary results suggest that benzene in blood is more reliable than phenol tests for assessing both exposure and uptake of benzene. Normal values of phenol in urine (10 mg/liter or less) were found in nearly all those cases in which benzene was detected in the blood.     

2015年郑州市饮用水放射性水平状况调查

目的了解郑州市不同地区、不同季节、不同水源类型的放射性水平。方法分别于丰水期和枯水期采集郑州市区黄河水源水、井水源水、丹江口水源水、出厂水和末梢水各一份;以县为单位,每单位采集出厂水、末梢水、水库水、河水、井水各1份,按《生活饮用水生活标准检验方法》(GB/T 5750.13-2006)检测饮用水中总α和总β放射性水平,依据《生活饮用水卫生标准》(GB 5749-2006)进行判定。结果丰水期、枯水期水体总α、总β放射性水平均低于国家标准限值。结论郑州市不同水源类型均处于正常的天然放射性本底水平。     

Occupational stress in nurses in psychiatric institutions in Taiwan

Nurses are known to be exposed to occupational stress. However, occupational stress is not well documented for nurses in psychiatric institutions in Taiwan. A cross-sectional study was conducted to explore the work-related stress and risk factors of nurses in psychiatric institutions in Taiwan. A structured questionnaire was distributed to nurses at five state-owned psychiatric hospitals in Taiwan in 2001. Demographic information, working environment, and personal health status were inquired. Occupational stress was assessed based on the Chinese version of Job Content Questionnaire (JCQ). General health status and mental health were evaluated by the International Quality of Life Assessment Short Form-36 (IQOLA SF-36). A total of 573 questionnaires were disseminated to nurses and 518 (90.4%) were satisfactorily completed by nurses, including 408 female full-time nurses who had been in their current work for more than 6 months. In the past one month, 17.2% of nurses reported being under significant stress often or always. Assault episodes were reported by 45.1% of nurses in the past 6 months. Among the nurses, 16.9%, 25.2%, 50.0%, and 7.8% belong to the "High strain", "Low strain", "Active", and "Passive" groups, respectively. Perceived occupational stress was associated with young age, widowed/divorced/separated marital status, high psychological demand, low workplace support, and threat of assault at work. Lower general health score was associated with low job control, high psychological demand, and perceived occupational stress. A lower mental health score was associated with low job control, high psychological demand, low workplace support, and perceived occupational stress. We concluded that nurses in psychiatric institutions are under significant stress related to work factors.     

Changes in nursing administration in supporting transplantation in Brazil

This historical and bibliographic study aimed to understand how Nursing was organized to support care in transplantation. The HISA, LILACS, BDENF, PERIENF and DEDALUS databases were consulted, and thirteen references were found, ten of which were scientific articles, two were master's dissertations and one was a doctoral thesis. The span of time chosen for study ranges from the date of the first kidney transplant in Brazil (1965), to the date of publication of the last scientific article found in the databases mentioned above (2003). After reading these articles, the ones that were similar in topic were grouped together, thus creating the thematic axis for the presentation of the results. The results showed that the Nursing profession has played an important and active role in transplants ever since the first procedure in 1965.     

2019年中国肿瘤流行病学研究进展

恶性肿瘤已成为中国居民的主要死因之一。近些年来,中国政府积极推进肿瘤预防和控制领域的研究工作,取得了很大的进步。本文简要汇总中国在肿瘤流行病学领域的研究进展,具体包括2019年的肿瘤负担、癌症危险因素及其干预、筛查和早期发现、癌症防治专项行动(2019-2022年)方案等方面,以期为我国肿瘤防治工作的有效开展提供技术支撑和理论依据。     

2012年绵阳市蔬菜中农药残留状况

目的 了解绵阳市2012年市售蔬菜中农药残留情况,为食用蔬菜监管提供依据.方法 全部样品均按照GB/T 5009-2003的方法进行农药的残留检测.依据GB 2763-2005《食品中农药最大残留限量》进行判定.结果 2012年共检测蔬菜165份,农药检出率和超标率分别为72.12％和23.64％.豆类、根茎类、叶菜类、瓜果菜类和食用菌类蔬菜检测农药残留超标率分别为8.00％、23.53％、36.00％、5.26％和27.03％,差异有统计学意义(x2=11.41,P＜0.01).不同种类农药超标率差异有统计学意义(x2 =62.42,P＜0.01).夏季和冬季蔬菜农药超标率差异无统计学意义(x2=3.44,P＞0.05).结论 绵阳市叶菜类蔬菜中农药残留情况较为严重,应采取有效措施,加强蔬菜的监督管理,从源头禁止高毒农药的使用,加大蔬菜种植、销售环节的监测,确保市民食用蔬菜的安全.