离子色谱-抑制电导法分别测定海水中阴离子和阳离子

以氢氧化钾为流动相,阴离子交换分离,抑制电导检测,可以同时分离F-、Cl-、Br-、NO3-、SO42-、PO43-I、-等海水中的常见阴离子,利用梯度淋洗可以使以上各种离子在其最佳保留时间和最佳峰形条件下出峰。以8 mmol/L H2SO4为淋洗液,阳离子交换分离,抑制电导检测,可以同时分离测定海水中的Na 、K 、Mg2 、Ca2 、Sr2 和Ba2 。在所采用的色谱条件下各阴阳离子均可以得到很好的线性和很低的检出限。     

顶空法测定海水中一氧化碳

建立了顶空分析法结合ta3000痕量气体分析仪测定海水中CO浓度的方法,对实验条件进行了选择,确定了环境温度、平衡时间和液气相比等最佳实验条件。结果表明,在20℃的环境温度下采用50mL玻璃注射器进行测定,液气相比为44∶6和平衡时间为5min能够较好地测定出海水中CO的浓度。在优化实验条件下,CO测定的线性范围为0～2.7×10-6(V/V),r=0.999,P<0.0001;相对标准偏差<4.4%;回收率为90.5%;检出限为0.02nmol/L。同时应用该方法测定了北黄海海水中的CO,测得CO的浓度是0.20～3.13nmol/L,表明该方法能够满足于海水中CO浓度的测定。     

Development of pre-concentration procedure for the determination of Hg isotope ratios in seawater samples

Hg concentrations in seawater are usually too low to allow direct (without pre-concentration and removal of salt matrix) measurement of its isotope ratios with multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). Therefore, a new method for the pre-concentration of Hg from large volumes of seawater was developed. The final method allows for relatively fast (about 2.5 L h⁻¹) and quantitative pre-concentration of Hg from seawater samples with an average Hg recovery of 98 ± 6%. Using this newly developed method we determined Hg isotope ratios in seawater. Reference seawater samples were compared to samples potentially impacted by anthropogenic activity. The results show negative mass dependent fractionation relative to the NIST 3133 Hg standard with δ²⁰²Hg values in the range from −0.50‰ to −1.50‰. In addition, positive mass independent fractionation of ²⁰⁰Hg was observed for samples from reference sites, while impacted sites did not show significant Δ²⁰⁰Hg values. Although the influence of the impacted sediments is limited to the seawater and particulate matter in very close proximity to the sediment, this observation may raise the possibility of using Δ²⁰⁰Hg to distinguish between samples from impacted and reference sites.     

大体积进样-原子荧光光谱法 测定海水中痕量汞

海洋中的汞在生物体内会转化为毒性高的甲基汞,影响海洋生物体的健康,进而威胁到人类的健康。同时,由于汞元素的记忆效应,使其会残留在光谱仪器设备中,影响仪器空白值和参数设置,以及测量结果的准确性和可靠性。海水中的汞含量处于超痕量水平,其分析检测是目前的难点之一。本文研究了一种大体积进样-原子荧光光谱法测定海水中痕量汞的方法,考察了不同前处理方式、酸的种类、还原剂浓度和原子化方式对检测的影响,并针对性利用烷基汞验证了不同条件下的检测结果,对方法进行了改进和验证,并对不同海域的海水进行了检测。实验结果表明：采用大体积进样,用盐酸代替硫酸,检测低浓度样品结果更准确;用甲基汞、乙基汞加标和低浓度还原剂对比验证过硫酸钾消解前处理时室温消化24h和加热煮沸1min两种消解方式,两种方式的加标回收率均接近100%;测量不同海域海水样品平行性好,结果准确,该方法对不同海域海水具有普遍适用性。     

石墨炉原子吸收光谱中海水的背景吸收研究

由于海水的成分复杂,含盐量高,给用石墨炉直接测定其中的痕量杂质带来许多困难^[1]。Sturgeon等用预先分离的方法来克服干扰^[2]。为了进行直接测定,研究海水背景吸收的来源、特点和消除方法是重要的。海水背景吸收的波长特性和在石墨管内蒸发行为的研究表明,海水的背景吸收主要来自氯化钠。时间特性的研究表明,背景吸收的时间分布及背景峰高与原子化阶段的加热方式和原子化温度有关。作者还研究了基体改进。剂和其它减小背景吸收的方法。     

超浸润光热材料的构筑及其多功能应用研究

随着工业社会的不断发展,不同行业对于超浸润材料的功能提出了更高的要求,超浸润材料向多功能化或智能化转型成为其发展的必然趋势。同时,在人们对环境问题日益重视的背景下,符合环保可持续、高效、低耗的新技术受到关注,具有光热效应的超浸润材料作为实现油水分离、海水淡化及太阳能蒸发等领域的新兴产品而成为研究热点。本文首先介绍了近年来碳基、有机物基、半导体基及复合型超浸润光热材料构筑的研究现状并对其局限性进行了分析,然后梳理并详细论述超浸润光热材料在防覆冰、海水淡化、油水分离等领域的应用进展及其作用机理,进而总结了其目前制备过程中存在的环境危害性等问题,并对功能性与智能型超浸润光热材料的发展趋势及研究路线进行了展望。     

Assessment of heavy metal pollutants at various sites along the Jordanian coastline of the Gulf of Aqaba,Red Sea

This research investigated the levels of 16 trace and heavy elements in seawater for the first time in the northern Gulf of Aqaba. The concentrations of four selected sites along the Jordanian coast. The elements were determined by using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Observed concentrations of Co, Cu, Ni, and Zn in seawater were higher than the threshold levels that were recommended by the Australian Water Quality Guidelines. The levels of As and Se in seawater were also higher than previously reported values from Arab seas. Moreover, it could be concluded that the Gulf of Aqaba (Jordanian coast) is highly contaminated by Ni, due to seawater concentrations exceeding both Australian and US EPA guidelines. Based on the results of this study, additional investigations are necessary to determine the anthropogenic activities that may cause this pollution. The determination of elemental concentrations in biota and sediment is also highly recommended for the Jordanian coast. This study and future studies will be useful for assessment and monitoring of marine pollution in the Gulf of Aqaba.     

FTIR光谱的海水入侵区水-岩(土)间氟迁移机理分析

滨海地区饮水型氟中毒和海水入侵十分普遍。海水入侵引起地下水性质的改变对岩（土）氟迁移具有潜在影响，但尚未有直接模拟实验证实，其氟迁移机理也不明确。用淡水和海（卤）水混合及配制溶液模拟海水入侵过程，对含水砂层沉积物进行静态水-岩（土）氟迁移模拟实验，对比分析沉积物FTIR特征，探讨海水入侵对岩（土）氟迁移影响规律及机理。结果表明，含水砂层沉积物氟迁移量大小顺序为：海水＞1∶1淡海＞淡水；卤水＞1∶1淡卤＞淡水，随海（卤）水混入程度增加，含水砂层沉积物岩（土）氟迁移能力增强。氟迁移能力随NaCl和NaHCO₃浓度增加而增加，随CaCl₂浓度增加而降低。对含水砂层沉积物傅里叶红外吸收光谱（FTIR）分析表明，随NaCl和NaHCO₃浓度增加，NaCl溶液中沉积物Si-O-Si键伸缩振动峰强度明显增强，氟磷灰石弯曲振动峰减弱，O-H键特征峰变化不明显，而NaHCO₃溶液中沉积物羟基磷灰石弯曲振动峰和Si-O-Si键伸缩振动峰强度变化不明显，O-H键特征峰强度变化明显，表明NaHCO₃溶液主要通过OH-与F-离子交换，而NaCl溶液是通过Si-O-Si键中Si-O置换来影响岩（土）氟迁移。随CaCl₂浓度增加，Si-O-Si键伸缩振动峰强度明显减弱，氟磷灰石弯曲振动峰强度增强，表明Ca2+强烈地抑制岩（土）氟析出。同时，随NaCl和NaHCO₃浓度增加和CaCl₂浓度减少，Si-F特征峰强度减弱，Si-O-Si键弯曲振动峰向低波数偏移。由于大气CO₂混入，1 mol·L-1 CaCl₂作用沉积物出现1 460和1 420 cm-1碳酸根特征峰。由于碳酸根沉积作用，1 mol·L-1的NaHCO₃作用的沉积物在1 460 cm-1处峰强度增强，且在875 cm-1出现新峰，但是在淡海卤水和NaCl溶液作用的沉积物中无碳酸根特征峰，表明含水砂层中无萤石（CaF₂）溶解作用。海水入侵引起的偏碱性、高钠低钙的环境促进岩（土）氟迁移释放，是滨海地区高氟地下水重要动力。     

海水重金属电化学传感器检测系统

研制了一种新型的海水重金属电化学传感器流动分析系统.通过在线过滤、紫外线消解、电化学富集以及离子选择性电极电位测定等过程,实现对海水重金属的高灵敏、高选择性的快速检测.在海水基体条件下,对于镉、铅和铜的测定线性范围分别为1.0×10-9～1.0×10-7 mol/L,3.0×10-9～1.0×10-7 mol/L和1.0×10-9～1.0× 10-7 mol/L,相应检出限为2.8×10-10,6.6×10-10和5.1×10-10 mol/L,连续6次测定的RSD均小于5％,全程分析在25 min内完成.应用于实际海水样品分析,其测定结果与溶出伏安法一致.此传感器性能可靠、成本低廉,在海水重金属现场快速监测方面具有良好的应用前景.     

Determination of bismuth in open ocean waters by inductively coupled plasma sector-field mass spectrometry after chelating resin column preconcentration

A novel low-blank method is described for the analysis of bismuth in seawater based on preconcentration using an ethylenediaminetriacetic acid chelating resin column followed by determination with inductively coupled plasma sector-field mass spectrometry (ICPSFMS). A sample is siphoned into and drains through the column with the flow rate being kept constant by using a flotation device. Bi in 250 mL of acidified seawater is extracted onto the column in this process and eluted with 2 mL of 3 M HNO₃ followed by 3 mL of ultra-high purity water. The concentration of Bi in the eluate is measured by ICPMS. The benefits of the method compared to others are its simplicity, a smaller amount of seawater, and lower procedural blanks and detection limits at pg kg⁻¹ levels. Data on dissolved Bi in open ocean reference samples of SAFe and GEOTRACES programs are presented for the first time.