火焰原子吸收光谱法测定人尿样品中微量元素锶

<正> 现代医学研究发现:微量元素锶是人体骨骼组织中重要元素之一,它能客观反应出人体骨科疾病的情况成功地分析尿液中锶含量在医学上有很大的应用价值,前人在测定头发、血液,人尿中锶的含量方面有过报导但采用火焰原予吸收法测定人     

原子吸收分光光度法测定矿泉水中的锶

锶是人体必需微量元素，是构成人体骨骼和牙齿的正常组织成份。锶还可降低心血管疾病的死亡率。我国饮用水源水中锶含量甚微，不少矿泉水中都含有丰富的锶，锶含量在0．20～0．40mg／L和偏硅酸含量在20～30mg／L为天然饮用矿泉水。矿泉水中的锶测定方法GB／T8538—1995技术规范为EDTA、高浓度镧火焰原子吸收分光光度法。在实验运用时，前法加入EDTA2Na后标准曲线和样品管均产生大量晶状沉淀物，无法测定，后法因大量的金属离子对锶测定干扰使检测结果回收率偏高。为此，我们对此做了相应的研究改进，取得较为满意的结果。     

用显微结晶法研究钙——锶分离

原子弹爆炸,通常可产生35种放射性元素,其中包括200多个同位素。而对人体危害最大的有~(90)锶等,因为~(90)锶半衰期长(28年),裂变产额高5.6～5.8%,和钙具有相似的化学性质,常和钙一起随食物链进入人体,主要蓄积在骨骼内,生物半衰期长达4000天,因此对人体会造成长期内照射。所以~(90)锶是核裂变产物污染外环境的主要指标之一,已引起世界各     

锶与人体健康关系

锶在轻工业、电子产业和冶金等行业应用广泛。作为人体的一种必需微量元素,锶在人体健康中的作用,相关报道尚不多见。对已有文献中锶的化学性质、应用情况、来源、人均日需求量以及缺乏或过量时导致的人体常见健康问题进行分析,我国人群目前没有摄入过量锶的风险,有意识地进食富含锶的食品,有利于增进骨骼健康和减少心血管等慢性疾病发生率,锶型矿泉水和陆生藻类或可作为优良的膳食补充剂备选材料。     

饮用水中锶卫生标准的研制

锶是一种白色碱土金属,原子量8762,比重25,熔点757℃,与钙同属周期系中ＩＩＡ族元素,皆属二价化合态,都属于亲骨型分布,含钙较多的器官也含有较多的锶。目前由于对必需微量元素的理解不同,以及对锶在人体内确切的生理功能没有研究证据,所以锶是否为人体所必需的微量元素尚有不同结论〔1,2〕。由于锶的离子半径与钙的离子半径相似,故易发生相互间离子交换。锶在骨骼中竞争性抑制骨组织的钙化〔3〕。高锶低钙时可引起动物“锶佝偻病”。1　制定饮水中锶卫生标准的必要性饮水中锶的问题的提出是因我国农村改水引出的新情况。我国农村从50年代开…     

锶与骨质疏松症

骨质疏松是以骨密度、强度下降,脆性增加以及易于发生骨折为主要症状的一种全身性骨胳疾病。大量的研究表明,锶元素对体内骨骼中代谢有显著影响,锶既可抑制骨吸收,又可促进骨形成的作用。因此,锶盐具有抗骨吸收和增进骨形成双重作用,代表了在骨质疏松症治疗上一个新的重要发展方向。针对锶对骨代谢的影响进行综述。     

饮食慎防氟中毒

一、前言 氟是人体必需的微量元素之一,除职业接触外,人体中的氟主要来源于饮用水和食物。氟在人体内主要由胃吸收,饮水中的氟可被完全吸收,食物中的氟一般可被吸收75％～90％。通过饮水和食物中摄入的氟会在身体内蓄积,所以如果饮水和食物中氟含量过高,就容易导致一种全身性慢性中毒疾病——氟中毒,引起氟斑牙和氟骨病,严重的会发生骨骼变形,甚至瘫痪。它对人体的危害很大,因此,我们在生活中要     

钦水锶对大鼠骼生长发育影响的实验研究

研究了高锶饮水对大鼠骨骼生长发育的影响。结果表明，饮水中锶浓度为５－５００ｍｇ／Ｌ达１２周可引起Ｗｉｓｔａｒ大鼠血清、尿、股骨、颌骨和牙齿中锶含量增高，呈明显的剂量－反应关系。同时，锶还可使骨骼钙含量降低，牙齿钙含量和骨骼的骨密度增主同，以及除第１２周生大鼠外血清钙水平下降。     

儿童所需营养及其特点之五——矿物质

矿物质对儿童生长发育至关重要,因为它是人体的重要组成成分。人体所需矿物质的种类很多,有钙、磷、铁、锌、碘、钠、镁等。下面介绍几种最重要的矿物质。 钙:钙是生长骨骼、牙齿的主要原料。钙总量的99％沉着于骨骼和牙齿     

锶与佝偻病

一般情况下,锶的代谢和分布与钙相似。两者主要贮存在骨骼和牙齿。高锶地区的土壤锶一大于３５０ｍｇ／ｋｇ的乡村儿童中,符合佝偻病诊断体征一项或一项以上者的发病率为３１．５％;低于３５０ｍｇ／ｋｇ锶以下者,发病率为１９．５％。动物实验证明：给锶后能引起骨骺生长板蛋白我糖及软骨胶原的变化。过量锶可引起软骨大分子结构的发迹并发生佝偻病。     

氟、锶与骨质疏松症

氟、锶骨有特殊的亲和力,对骨代谢有特殊的影响。小剂量的氟制剂能中度增加骨量,用氟治疗6个月BMD就可有统计学意义。在治疗用剂量下锶盐具有拆耦联作用,在保持骨形成的同时抑制骨吸收,是非常有前景的治疗骨质疏松的药物。     

Calcium intake,calcium bioavailability and bone health

Calcium accounts for 1-2 % of adult human body weight. Over 99 % of total body Ca is found in the teeth and bones. Therefore, in addition to the obvious structural role of the skeleton, it also serves as a reservoir for Ca. Dietary Ca intake has an important impact on bone metabolism and bone health. Chronic Ca deficiency resulting from inadequate intake or poor intestinal absorption is one of several important causes of reduced bone mass and osteoporosis. It is vital, therefore, that adequate dietary Ca is consumed at all stages of life - in early life so that the genetically programmed peak bone mass can be reached and in later adulthood so that the skeletal mass can be maintained and age-related bone loss minimised. Unfortunately, there is wide variation in the estimates of daily Ca requirements made by different expert authorities. Furthermore, there is evidence that many individuals are not consuming these recommended levels. The consequence of this for bone health will be discussed in the present review. Besides the amount of Ca in the diet, the absorption of dietary Ca in foods is also a critical factor in determining the availability of Ca for bone development and maintenance. Thus, there is a need to identify food components and/or functional food ingredients that may positively influence Ca absorption in order to ensure that Ca bioavailability from foods can be optimised. This approach may be of particular value in individuals who fail to achieve the dietary recommended level of Ca.     

Solubility of various forms of strontium titanate in lungs: in vitro and in vivo studies.

At the In-Tank Precipitation Facility of the Savannah River Site, strontium and other radionuclides are removed from high-level radioactive waste and sent to the Defense Waste Processing Facility. Strontium removal is accomplished by adsorption using a slurry that includes monosodium titanate, which forms strontium titanate with unknown lung solubility characteristics. The purpose of this study was to determine the solubility of strontium titanate in the form created at the In-Tank Precipitation facility. An in vitro dissolution study was done with a slurry simulant and with several types of strontium titanate, and the results were compared. An in vivo study was also performed with high-fired SrTiO3 in rats. Strontium and titanium were measured by inductively-coupled plasma/atomic emission spectrometry. The data from both studies were used independently to assign the compounds to an absorption type based on criteria specified in ICRP 71. Results of the in vitro studies showed that the Defense Waste Processing Facility simulant should be assigned to Type M and the strontium titanate should be assigned to Type S. Results of the in vivo study verified that SrTiO3 should be assigned to Type S. Lung clearance data of SrTiO3 from rats showed that 85% cleared within the first 24 h and the remaining 15% cleared with a half-time of 130 d. The initial rapid clearance is attributed to deposition in airways as compared to the alveolar region.     

Methods for assessing gastrointestinal absorption of strontium in humans by stable tracer techniques

Intestinal absorption of strontium from an oral test dose was studied in 13 healthy human volunteers using double tracer techniques with two stable strontium isotopes as tracers. Defined amounts of one isotope were administered orally, while tracer amounts of the second isotope were injected intravenously. Two different methods were used to assess the total fraction absorbed (f1 value). Fractional intestinal strontium absorption can be calculated from the ratio of the two isotopes in plasma or urine samples (in this paper called the double-isotope method) or the convolution integral technique, since both methods provide an accurate estimate of fractional absorption and yield comparable results. The latter additionally provides information on the absorption kinetics in the gastrointestinal tract. The absorption varies with respect to the chemical form and to the amount administered. Absorption patterns are characteristically different for uptake from solutions or from whole meals.     

Strontium biokinetics in humans: influence of alginate on the uptake of ingested strontium

Radioactive isotopes of strontium, mainly 90Sr, released into the environment due to nuclear accidents may contribute significantly to the internal radiation exposure of members of the public after ingestion of strontium with contaminated foodstuffs. The committed radiation dose is significantly dependent on the fraction of the ingested activity that crossed the gut wall (f1 value). In tracer kinetic investigations, the effect of sodium alginate on the gastrointestinal absorption of strontium was studied in human subjects. Sodium alginate was proven to be a potent agent for reducing strontium absorption with high efficiency and virtually no toxicity. The data obtained show that the uptake of ingested strontium from milk was reduced by a factor of nine when alginate was added to milk. It is concluded that alginate preparations are a suitable antidote against radiostrontium.     

硅与人体健康

硅是人体中含量较多的必需微量元素之一,它在人体中参与骨的钙化过程,有助于结缔组织细胞形成细胞外的软骨基质,维护心血管正常功能,有一定的抗衰老效果。人体缺硅影响骨骼的正常发育和导致冠心病,若长期过量摄取硅会导致人体抗氧化功能降低,有可能使硅在泌尿系统堆积,生成尿结石。     

Variability in the concentrations of Ca, Mg, Sr, Na, and K in the opercula of perch (Perca fluviatilis L.) in relation to the salinity of waters of the Oder Estuary (Poland)

Macro-ionic composition of fish opercula may be an indicator of the fish stock identity. This is especially interesting in river estuaries, where individual sections of the estuary may differ in terms of their hydrochemical regimes. Diversified macro-ionic tissue composition is likely to provide clues not only about the origin of an individual fish, but also about its possible migration routes. The current study researched this aspect of the chemical composition of perch collected from different sections of the Oder River estuary. A total of 60 European perch, Perca fluviatilis L., were obtained from 3 sampling sites located in the river at Widuchowa, Szczecin Lagoon, and Pomeranian Bay, where waters are subject to dynamic macro-ionic transformations. Fish length ranged from 20 to 25 cm. Opercula of the fish were examined for their content of calcium, magnesium, strontium, sodium, and potassium, with the aid of the flame method using a Perkin-Elmer 3100 atomic absorption spectrophotometer. Perch inhabiting the waters of the Oder River between Widuchowa and Szczecin Lagoon had their opercula composed predominantly of calcium. Calcium was also the predominant ion dissolved in the water in this area; Ca represented 83.6% of all cations in the water and 41.6% of those present in the bones of the perch operculum. The increased levels of salinity near the sea were associated with the replacement of calcium in bones by other, more readily available elements (magnesium or strontium). Differences in the observed macro-ion composition of the opercula were sufficient to assign the perch studied to two distinct groups inhabiting fresh and brackish waters.     

Reduction in the absorption and retention of strontium in rats

Rats were fed a stock diet supplemented with calcium phosphate and sodium alginate, both separately and simultaneously, over a period of 4-5 months. Observations were made at intervals on the growth rate and on visual and histological abnormalities in some body tissues. No toxic effects were observed. The absorption and skeletal retention of calcium for rats on the combined supplements remained almost unchanged but the absorption and retention of strontium was reduced 7-fold.     

Biokinetics of embedded surrogate radiological dispersal device material

The terrorist use of a radiological dispersal device (RDD) has been described as "not if, but when" (). Exposures from such an event could occur by a number of routes including inhalation, wound contamination, or embedded fragments. Several of the radionuclides thought to be potential RDD components are metals or ceramic material. The use of such material would increase the potential for wounds from embedded fragments of radioactive material. To date, most research in this area has focused on inhalation exposures, while the consequence of embedded fragment exposure has not been investigated. This study modified a previously used rodent model in order to determine the biokinetics of intramuscularly implanted nonradioactive surrogate RDD material. Cobalt, iridium, or strontium titanate was embedded into the gastrocnemius muscle of Sprague Dawley rats. The rats were euthanized at 1, 3, or 6 mo post-implantation. Tissue metal analysis showed that iridium did not solubilize from the implanted pellet, while cobalt and strontium did so rapidly. Cobalt was found in all tissues analyzed, but it was localized mainly to kidney and liver as well as being excreted in the urine. Strontium was found in lung, liver, and spleen, as well as being deposited in bone. However, the greatest strontium concentrations were found in the popliteal lymph nodes, the lymph nodes responsible for draining the area of the gastrocnemius. These results indicate that, depending upon the material, a variety of treatment strategies will be needed when dealing with embedded fragment wounds from a radiological dispersal device event.