盐酸标准物质的研制

本文介绍了盐酸标准物质的研制程序，其中包括溶液的配制、均匀性和稳定性检验、分析方法和数据统计处理方法等。并选择了具有高准确度的精密库仑法和自动电位滴定法分析定值，对制备浓度为０．００６ｍｏｌ／ｄｍ３盐酸标准物质，其定值的相对不确定度可达０．２％，稳定期在一年以上。     

海水中砷标准物质的研制

本文介绍了海水中砷标准物质的研制过程，其中包括溶液的配制、均匀性和稳定性检验，标样的分析方法。并对标准物质的定值数据进行统计处理，两种浓度的定值结果分别为：１．００μｇ／ｃｍ３±０．０４μｇ／ｃｍ３和５１．０μｇ／ｄｍ３±２．６μｇ／ｄｍ３。两种浓度砷标准物质的稳定期均为一年     

海水中硒标准物质的研制

本文介绍了海水中硒标准物质的研制过程，其中包括溶液的配制、均匀性和稳定性检验以及标样的分析方法。并对标准物质的定值数据进行统计处理，海水中硒两种浓度的定值结果分别为１．００±０．０５μｇ／ｃｍ３和２０．０±１．２μｇ／ｄｍ３。稳定期均为一年。     

磷酸盐系列标准物质的研制

本文介绍了供测定水和海水中活性磷酸盐含量的标准物质的研究程序。其中包括了标准物质的配制、均匀性和稳定性检验、分析方法和数据统计处理等。并采用离子色谱法和分光光度法进行定值，对制备浓度分别为０．４０、０．８０、１．６０、３．２０、４．８０μｍｏｌ／ｄｍ３的磷酸盐标准物质，其相对不稳定度分别为３％、２％、１％、１％、１％。稳定期为一年以上。     

海洋动物标准物质的研制及其技术流程

以缢蛏为例,详细介绍了海洋动物标准物质的研制及其技术流程,对研制过程中候选物的确定,以及标准物质所必须具备的特性量值等进行了全面叙述.海洋动物标准物质制备的技术流程主要包括:均匀性、稳定性和准确性的检验,定值分析方法、数据的统计分析以及定值数据结果的表达.有证标准物质的包装运输、认定证书和标签等方面的操作也都应按照规定...     

标准物质的作用及其应用

标准物质是高度均匀、良好稳定和量值准确的测量标准 ,也是中华人民共和国计量法中依法管理的计量标准。它具有复现、保存和传递量值的基本作用。在物理、化学、生物与工程测量等领域中用于校准测量仪器和测量过程、评价测量方法的准确度和检测实验室的测试能力、确定材料或产品的特性量值、进行量值仲裁等[1 ] 。国家海洋局第二海洋研究所从 1 976年起开始研制标准物质 ,至今已研制并批量生产了多项国家级标准物质 ,其中获国家一级标准物质证书和制造计量器具许可证的共 9项 :盐酸溶液标准物质 ( GBW0 862 2 )、碘酸钾溶液标准物质 ( GB…     

黄海沉积物标准物质研制

报道了中国黄海海洋标准物质的研制过程,其中包括样品的采集、制备,均匀性检验、稳定性考察以及定值分析方法,并对数据进行了数理统计,给出了标准物质的定值数据。最后确定标准值45个,参考值8个,信息值11个,共计测定元素64个。     

南海颗粒物的氨基酸通量与组成

本文对在南海中部布设的两个层次（１１９１ｍ和３６９６ｍ）沉积物捕集器的沉降粒子进行了颗粒沉降通量和氨基酸组成的研究。南海的物质通量呈现季节性变化，深层样变动范围在６９．６～１４１．７ｍｇ／（ｍ２·ｄ）；但火山灰侵入后，其物质通量（按每月平均）高出１～２个数量级，氨基酸和氨基糖含量亦由原来的１０×１０－３和０．９×１０－３减少为０．０９×１０－３和０．０２×１０－３。氨基酸组分中以天门冬氨酸占优势，其次为甘氨酸与谷氨酸。在火山灰影响下，其丰度顺序为：谷氨酸＞天门冬氨酸＞甘氨酸。     

海水基质活性磷酸盐标准物质研制

本研究以西太平洋表层海水为基质,制备了浓度为0.5～4.0μmol/L的海水活性磷酸盐系列标准物质。通过对所研制的4批次样品进行均匀性、稳定性评估,确定样品性能良好。对基于磷钼蓝分光光度法的气泡间隔连续流动分析系统的反应和操作条件进行优化,优化后的方法检出限低至0.03μmol/L。不同浓度样品的相对标准偏差为0.37%～2.45%(n=9);通过与国际已有有证标准物质比对,本研究方法测量误差小于0.05μmol/L。经6家具有中国计量认证资质且具备海水磷酸盐检测能力的实验室联合定值,确定了该系列标准物质的标准值,并对定值结果的不确定度进行了分析评价,相对扩展不确定度为2%～10%。     

南海东北部沉积物间隙水氮和硅的研究

测定了南海东北部沉积物间隙水中ＮＯ３－Ｎ，ＮＯ２－Ｎ和ＳｉＯ３－Ｓｉ的含量。６个站位的５─１０ｃｍ层的ＮＯ３－Ｎ，ＮＯ２－Ｎ和ＳｉＯ３－Ｓｉ的含量分别为０．４７—１．７０，０．８４—２．６０和１０．１７—１１．６９μｍｏｌ／Ｌ。研究了上述物质含量在５０号站的深度分布。估算了ＮＯ２－Ｎ和ＳｉＯ３－Ｓｉ从间隙水向上覆水扩散的通量分别为０．０３３和０．０１９ｍｍｏｌ／ｍ２·ｄ。     

A comparative study of three methods for the determination of iodate in seawater

A comparative study of three methods for the determination of iodate-iodine in seawater is described. In one method the iodate is determined polarographically while in the others the iodate is determined colorimetrically as iodonium ions. In one of the colorimetric methods each sample is pre-treated with excess iodine-water in an attempt to eliminate suspected interference from naturally occurring reducing agents. The tests were conducted on a selection of open-ocean and near-shore waters with iodate concentrations ranging from 0 to 60 μg 1^?1-I. The tests indicated that the polarographic method and the colorimetric method without iodine-water give the more reliable measurement of iodate concentration. Also, the method with iodine water was found to be in error especially at low iodate concentrations. Reducing agents, if present, were found not to interfere significantly.     

On the feasibility of some photochemical reactions of iodide in seawater

Aerated solutions of potassium iodide in de-ionised water, of between 5–20% (w/v), were exposed to ambient spring sunlight to estimate the rate of photochemical production of molecular iodine from iodide and oxygen in seawater. This rate cannot be measured directly as other reactions, for example the reduction of molecular iodine by organic matter, interfere. Also, a parallel photo-oxidation, initiated by organic matter in real seawater, may also occur. The experiments yield a half-life for iodide in tropical surface waters of about 29 months suggesting that the reaction is insignificant. At this rate it will not compete effectively against the reduction of molecular iodine by organic matter, and hence molecular iodine should not appear. The experiments also consider the photo-oxidation by nitrate, and iodate, a combination of nitrite and oxygen, and eliminate significant interference by chloride, bromide and the phosphate buffer. The rate of photo-oxidation with each of the first three oxidations is found to be first order with respect to oxidant concentration. The variation of photo-oxidation rate with pH is also studied, with a brief investigation without conventional oxidant, where electron cage complexes still promote photo-oxidation. The photochemical action spectrum for these reactions in sunlight is shown to extend between 300 and 425 nm. The photo-oxidation of iodide by iodate is more interesting to marine chemistry as the photo-reduction of iodate. Nevertheless, the reduction-rate is judged to be several orders too low to be significant in seawater. The mechanism of the reactions are discussed and lessons drawn on the stability of potassium iodide solutions used in iodate analysis. The KI actinometer is recommended to those studying other photochemical systems activated by UV-A light as it is linear and very simple and reliable.     

海水中无机混合元素标准样品的研制

对海水中无机混合元素标准样品进行了研究和制备。样品采用高纯试剂重量法制备,以人工海水为样品介质,用原子吸收法和原子荧光法对样品进行均匀性和稳定性研究;多家实验室协作分析定值后数理统计确定标准值,并进行不确定度评估。结果表明,海水中无机混合元素标准样品的均匀性和稳定性良好;可用于海水污染监测的仪器较准、分析方法的评价与验证、实验分析的质量控制和能力验证等方面。     

海山富钴结壳标准物质研制

报道了我国与俄罗斯合作研制的三个海山富钴结壳标准物质GSMC-1,2,3.这三个标准物质的原样分别取自西太平洋麦哲伦海山和中太平洋海山.样品经风干、选配、球磨制备成均匀的粉体样品,其均匀性采用高精度的X-射线荧光光谱法检验.样品的化学组分采用国内外多实验室协同分析方式定值,有八个国内实验室和八个国外实验室参加了合作分析.测试组分均为57个,其中GSMC-1,2有43个组分定为保证值,10个组分作为参考值;GSMC-3有45个组分定为保证值,8个组分作为参考值.经2a多的试用,三个标准物质已于2005年被国家计量部门批准为国家一级标准物质,其编号分别为GBW07337,GBW07338和GBW07339.     

Studies on the determination of inorganic iodine in seawater

Existing methods for the determination of the various forms of iodine present in seawater are laborious or unwieldy in use. This paper describes modified forms of the iodate and total iodine methods described by Barkley and Thompson (1960), a spectrophotometric procedure for iodate determination derived from Johannesson's (1958) work, and an automatic method for total iodine determination. Procedures for iodate and total-iodine determination which are suitable for use aboard ship, are recommended. Both procedures for iodate determination returned a standard deviation close to 0.5 μg/l when several replicate samples of a seawater containing approximately 30 μg/l of iodate-iodine were analysed. The automatic method for total iodine determination yielded a standard deviation of 0.8 μg/l by the repeated analysis of a seawater containing a total of approximately 50 μg/l of iodine. Suitable methods for the filtration and storage of seawater are also described.     

The biogeochemical effect of seaweeds upon close-to natural concentrations of dissolved iodate and iodide in seawater – Preliminary study with Laminaria digitata and Fucus serratus

Toward assessing the biogeochemical significance of seaweeds in relation to dissolved iodine in seawater, the effect of whole seaweeds (Laminaria digitata and Fucus serratus) upon iodide and iodate, at essentially natural concentrations, has been studied. The weeds were carefully removed from the sub-littoral zone of the Menai Straits and exposed to iodide and iodate at their natural temperature (6 °C), but under continuous illumination. Laminaria digitata was found to decrease the concentration of iodate with an exponential rate constant of 0.008–0.24 h⁻¹. This is a newly discovered process which, if substantiated, will require an entirely new mechanism. Generally, apparent iodide concentration increased except in a run with seawater augmented with iodide, where it first decreased. The rate constant for loss of iodide was 0.014–0.16 h⁻¹. Meanwhile, F. serratus was found not to decrease iodate concentrations, as did L. digitata. Indeed, after ∼30 h iodate concentrations increased, suggesting that the weed may take in iodide before oxidising and releasing it. If substantiated, this finding may offer a way into one of the most elusive of processes within the iodine cycle – iodide oxidation. With both seaweeds sustained long-term increases of apparent iodide concentration are most easily explained as a secretion by the weeds of organic matter which is capable of reducing the Ce(IV) reagent used in determination of total iodine. Modelling of the catalytic method used is provided to support this contention. The possibility of developing this to measure the strain that seaweeds endure in this kind of biogeochemical flux experiment is discussed. A Chemical Oxygen Demand type of approach is applied using Ce(IV) as oxidant. The results of the iodine experiments are contrasted with the several investigations of ¹³¹I interaction with seaweeds, which have routinely used discs of weed cut from the frond. It is argued that experiments conducted with stable iodine may measure a different variable to that measured in radio-iodine experiments.     

The stability of dissolved inorganic species of iodine in seawater

An oxidation state diagram was used to study the relative stability of inorganic iodine species in an aqueous system. It is shown that although iodate is the most stable form, iodide may exist as a metastable form in a basic solution. Molecular iodine may undergo disproportionation to form iodide and iodate. Results from laboratory studies suggest that molecular iodine is rapidly taken up by seawater, and hypoiodite is probably formed. Hypoiodite is also unstable in seawater, and may react with organic matter or undergo autodecomposition. Direct reactions between molecular iodine and organic matter were not observed.