用氟硼酸根离子选择电极快速测定海水中的硼

建立了用氟硼酸根离子选择电极快速测定海水中硼的方法。预先用浓氢氟酸将硼转化成氟硼酸根,然后在pH4用氟硼酸根离子选择电极进行测量。样品中的Ca~(2 ),Cl~-,Br~-和I~-不干扰硼的测定。用本法对某些样品进行分析获得满意的结果。     

海水中硼的快速测定方法

海水、卤水及废水等样品中微量硼的测定方法很多,其中姜黄素法是测硼灵敏度最高的一种,现已被列入美国《水和废水标准检验法》第13版中。我们以姜黄素-分光光度法测定海水中微量硼时,在标准曲线中加入了与海水样相当的无硼人工海水,消除了阴阳离子的干扰,在半年多的海水中硼的间断性测定试验方面,获得了较满意的结果,其相对标准偏差为3.1％,测一批样品仅需4小时,因此,该法是测定海水中硼的快速准确的较好方法。     

海水中硼的测定方法

介绍了海水中硼的测定主要方法,包括容量法,分光光度法、极谱法、光谱法、离子选择电极法等及其研究进展。     

甲亚胺——H酸分光光度法测定海水中的硼

一、前言海水中硼的测定,对海洋环境化学、海洋地球化学及海洋生物化学的研究具有重要意义。硼的测定方法报导很多,但对海水中硼的测定报导较少。海水中硼的测定有甘露醇容量法,氟硼酸根离子选择电极法,萃取原子吸收法,分光光度法等。在分光光度法中主要有胭脂红酸法和姜黄素法。胭脂红酸法需在较浓硫酸介质中显色,给操作带来困难;姜黄素法需要蒸发阶段,方法比较繁琐。     

海水中硼的示波极谱测定法

海水中微量硼的测定.通常是用分光光度法[1]和光谱法。硼在通常条件下不会产生极谱波。因此不能用极谱法直接测定硼。B(Ⅲ)与铍试剂Ⅲ可形成较稳定的配合物。     

联合法制取低硼海水镁砂的研究

降低海水镁砂中硼的含量有许多方法,例如碱洗法、过碱法、吸附法和选择性吸硼树脂法等。我们先采用吸附法制得低硼海水(含B_2O_33ppm),再用改良过碱法进一步降低硼含量,可制得含B_2O_3为0.01—0.02%的低硼海水镁砂。比较结果,联合法降硼比单一法降硼优越。 用Mg(OH)_2作吸附剂,吸硼后变为含硼沉淀,经过碱洗脱硼后,可循环使用。     

海洋资源的化学——ⅩⅥ.一种新的钾试剂及其对海水体系中钾离子的富集性能

本文首次报道了一种新的钾试剂和用于海水直接提钾的高效富集剂:1,2,4,5-苯四酚-O,O',O″,O-四乙酸(简称TTAH₄),研究了这一多功能基化合物的合成方法及其对低浓溶液和海水中钾离子的化学行为,初步探讨了其捕钾机理和相应钾盐的化学结构,并确认TTAH₄作为络合给予体(Donor)通过与钾离子生成一种多核配位化合物(TTAH₃K),而达到预期的富集目的。这一设想已由元素定量分析的数据和分子光谱的测定结果所证实。     

海水中硫的微库仑法测定

在海水pH(7—8)条件下,硫主要呈HS~-离子存在。海水中硫化物的测定方法有比色法、离子选择性电极法和阴极溶出伏安法等。比色法测定的灵敏度较低,离子选择性电极可直接测定1×10~(-6)M的硫化物浓度,若与预富集法相结合测定的硫化物的最低浓度为10~(-9)M。近年来,冯建兴等人应用微库仑计测定了淡水水体中超痕重的硫化物’检出下限可达0.2ppb。但尚未见到用微库仑计测定海水硫化物的报     

海水中溴离子气相色谱测定法的研究

研究了用气相色谱测定海水及天然水中溴离子含量的方法,确定了最佳条件。天然海水,稀释200倍后;取10ml稀释水样,用氯胺T为氧化剂,将Br-氧化为溴,在六次甲基四胺催化的条件下,溴与丁酮反应生成溴代丁酮;用环已烷萃取后,用ECD检测器测定。此方法简便快速,对溴离子含量较低的天然水尤为适用。方法与碘量法相对照,取得满意结果。     

燃烧氧化-非分散红外吸收总有机碳分析仪测定海水DOC 的不确定度分析

采用实验测定和误差分析的方法, 对燃烧氧化-非分散红外吸收总有机碳分析仪vario TOC cube测定海水DOC 含量的不确定度进行了分析, 对导致测定结果不确定度的各分量进行了量化估算。结果表明, 其测定结果的不确定度主要来源于四个方面, 即样品重复性测量、标准曲线拟合、标准溶液配制(包括称量、定容、移液产生的不确定度, 标准物质纯度和相对原子质量产生的不确定度)及测量仪器本身, 相对标准不确定度分量分别为0.016、0.018、0.0086、0.0079。标准曲线拟合与样品重复性测量是影响海水DOC 测定不确定度的主要因素, 但标准溶液配制和测量仪器所引起的不确定度亦不可忽略。对实际海水DOC 浓度为1.20 mg/L 的样品分析,合成以上四种不确定度分量得到DOC 测定结果的标准不确定度为0.21 mg/L。按照正态分布,取扩展因子k=2, 则扩展不确定度为0.07 mg/L, 此海水样品中DOC 含量的测定结果应为(1.20±0.07) mg/L(k= 2)。     

用原子吸收光谱法直接测定海水中的锶

目前,化学法测定海水中的钙时,锶往往同时被测定,因此,海洋调查中,钙含量也包含了锶。如果能准确地测定锶,就可以使钙镁的结果更加准确。因此,建立一个准确、快速测定海水中锶的方法是很必要的。 通常锶的测定采用火焰光度法,或直接用石墨炉原子吸收光谱法,然而,前者需经离     

A modified analytical method for the shipboard determination of nanomolar concentrations of orthophosphate in seawater

A method for the determination of nanomolar concentrations of orthophosphate in oligotrophic seawater developed by Liang et al. (2007) has been modified to make it fully feasible for shipboard application and for faster sample throughput with minimized sample volume. The technique is based on the flow injection method with solid phase extraction on a Sep-Pak C18 cartridge and colorimetric detector. The Schlieren effect was minimized by rinsing the cartridge sequentially with 5 mL water and 2 mL 95% ethanol solution. With three micro pumps in parallel, savings of up to 80% in amount of reagents and 25% volume of seawater samples could be achieved in comparison to the previous method. Variation of stopped flow time and sample loading time gave 3 different standard curves, which corresponded to 3 linear ranges within 3.4 and 515 nM. The modified method permits the analysis of samples over a wide range of concentrations, and has been successfully applied to shipboard determination of trace orthophosphate in more than 200 seawater samples during a one-month cruise in the South China Sea. For seawater at concentrations of 20.6, 82.5, 206.2 nM orthophosphate, the relative standard deviations (RSD) (n = 6), determined daily for 6 days on board ship were 4.45%, 4.73% and 6.75%, respectively. Five seawater samples collected in the Station SEATS (South East Asia Time Series Station at 18°N, 116°E) were analyzed using the present method both on board and in a land-based laboratory, as well as with the magnesium hydroxide-induced coprecipitation (MAGIC) method, and showed no significant difference according to the statistical t-test.     

碘化钾碱性高锰酸钾法测量海水化学需氧量不确定度的研究

葡萄糖与谷氨酸以1:1的比例配制成标准物质,用人工海水和标准物质配制成系列标准溶液,根据碘化钾碱性高锰酸钾法对系列标准溶液的测量结果,获得了海水COD测量不确定度在全量程范围内的分布规律,即测量不确定度在高端大不恒定,在低端小恒定。     

Total organic carbon in seawater — comparison of measurements using persulfate oxidation and high temperature combustion

A method is described for the determination of organic carbon in liquid seawater samples by combustion at a high temperature. Although the method is not easy to perform, it has been successfully employed for a direct comparison to the standard method of persulfate oxidation. With seawater from the central western North Atlantic Ocean, the standard method measured an average of 78% as much carbon as the high temperature method. This indicates organic matter in seawater that is resistant to oxidation by persulfate; some of it appears to be of a colloidal nature. The persulfate resistant organic matter is most noticeable in a region below the surface 100 m and seems to decrease slowly with depth, indicating deep ocean biological utilization of organic matter. Due to a possible procedural error in the standard persulfate oxidation method, the differences indicated here may actually be conservative and the content of total organic carbon in the sea may be as much as twice as high as has been indicated by previous estimates.     

碱性高锰酸钾法海水化学耗氧量(COD)在线测量仪的研制

一种新型的海水COD在线测量仪已经研制出来,其采用了碱性高锰酸钾法和流动注射分析技术,仪器的测量结果与标准方法有很好的一致性,它们的相关系数超过0.98。     

Chemistry of marine resources——ⅩⅥ. A new potassium reagent and its enrichment behaviour for potassium ion in seawater

This paper first presents a new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater,i.e.,1,2,4,5-tetrahydroxybenzen -O,O'',O",O''"-tetraacetic acid (TTAH₄).The synthetic method of TTAH₄,its enrichment behaviour for potassium ion in low concentration solution and seawater,and the chemical structure of its corresponding potassium salt have been investigated.A mechanism which caused the uptake of potassium ion is suggested.Elementary analysis and IR-spectrum determination of the potassium salt proved correct evidence for a polynuclear complex,i.e., (TTAH₃K)_n.Thus,the mechanism which caused the uptake of potassium ion may be interpreted in terms of the formation of polynuclear chains as a continual sandwich type coordination complex.     

海水中溶解有机碳的测定方法

海水中溶解有机碳(DOC)的测定方法主要有过硫酸盐氧化法;紫外光氧化法和高温氧化法。近年来,随着仪器分析的进步,国外已出现能自动连续测定DOC的商售设备。 Menzel等发展的过硫酸钾氧化法,由于设备简单,容易实施,至今仍为很多人采用。     

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.     

东海外陆架及钓鱼岛以北海域鱼类、底栖生物的痕量金属测定

从海洋生物生态学本身的研究,生物体常量,微量元素的测定,前人已作了很多的工作。随着国防、工业及海上交通运输不断高速发展,各种工业废物大量抛入海洋,海洋污染日趋严重。为此,许多海洋学者又从海洋环境保护出发,对各个海域里的生物成分进行了监测,特别对生物体痕量金属的测定已作了大量工作[3-6]。测定的范围是广范的,从大洋到极地,从深海到岸边,而对受污染严重的港湾及河口的生物毒物研究得更多。