PRECONCENTRATION OF TRACE ZINC IN SEAWATER ON CPPI RESIN BY FIA AND ON-LINE DETECTION BY ICP-AFS

A quite new type of chelating resin Carboxymethylated Polyethylenimine-Polymethylenepolyphenylene Isocyanate(CPPI)is used for the preconcentration of Zn from high salt water such as seawater. The preconcentration is controlled through the technique of Flow Injection Analysis(FIA).The concentrated sample solution is then directly transferred to an Inductively Coupled Plasma-Atomic Fluorescence Spectrometer(ICP-AFS)for determination.The detection limit of Zn by the technique is about 0.06 ppb.

Study of pressure effects on ocean in-situ detection using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy(LIBS) has attracted extensive attention as a new technique for in-situ marine application. In this work, the influence of deep-sea high pressure environment on LIBS signals was investigated by using a compact LIBS-sea system developed by Ocean University of China for the in-situ chemical analysis of seawater. The results from the field measurements show that the liquid pressure has a significant effect on the LIBS signals. Higher peak intensity and larger line broadening were obtained as the pressure increases. By comparing the variations of the temperature and salinity with the LIBS signals, a weak correlation between them can be observed. Under high pressure conditions, the optimal laser energy was higher than that in air environment. When the laser energy exceeded 17 mJ, the effect of laser energy on the signal intensity weakened. The signal intensity decreases gradually at larger delays. The obtained results verified the feasibility of the LIBS technique for the deep-sea in-situ detection, and we hope this technology can contribute to surveying more deep-sea environments such as the hydrothermal vent regions.

Impedance characteristics for solid Ag/AgCl electrode used as recording electric field generated by vessels in seawater

Ag/AgCl electrode has been prepared using pressed powder techniques. In order to verify the feasibility of this type of electrode used as detecting electric field generated by vessels in seawater, its characteristics of DC resistance, low frequency AC impedance, and receiving impedance in artificial seawater have been studied by polarization measurements, low frequency electrochemical impedance spectra, the open and short circuit cell conditions. The results show that the electrode can keep a low resistance when it responses the weak electrostatic field in seawater. The AC impedance of the electrode decreases as the frequency of the signal increasing. The receiving impedance decreases when the frequency of external field increases too. The valid detection bandwidth is determined by the properties of the impedance and the reactions occurring on the surface of the electrode.

Amalgamated gold-nanoalloys with enhanced catalytic activity for the detection of mercury ions(Hg^2+)in seawater samples

Mercury(Hg)is extremely toxic,and continues to cause major threats to aquatic life,human health and the environment.Hg^2+mainly derives from seawater as a product of atmospheric deposition,therefore there is great demand for sensing approaches that can detect Hg^2+in seawater samples.Herein,we demonstrate that the peroxidase-mimicking activity of gold nanoparticles(AuNPs)or so-called nanozymes,can be exploited for the detection of Hg^2+ions in various water samples.In a high electrolyte environment,the catalytic activity for the oxidation of 3,3’,5,5’-tetramethylbenzidine(TMB)was significantly diminished due to poor stability of the bare-AuNPs.This activity was reduced by-73.7%when the NaCl concentration was higher than 1.168%,which is much lower than that of seawater(-3.5%),thus presenting its unsuitability for detecting Hg^2+in harsh water matrices.To overcome this limitation,AuNPs were first functionalized with oligo-ethylene glycol(OEG),of which their colloidal form presented high stability in NaCl concentrations up to 20%and across a wide range of pHs from 1-14.Interestingly,the catalytic activity of OEG-AuNPs for the oxidation of TMB was strongly suppressed by the coating,but enhanced upon formation of Au-Hg amalgamation.This novel finding underlies a straightforward,sensitive,and highly selective detection platform for Hg^2+in water samples.The approach could detect the exposure limit level for Hg^2+in drinking water(i.e.,2 ppb for tap and bottled water)as set by the United States Environmental Protection Agency(EPA)and the World Health Organization(WHO).When Hg^2+was spiked into a 3.5%saline solution and a coastal seawater certified reference material(CRM),the detection limits were found to be 10 ancM 3 ppb,respectively,which exceed the Hg^2+concentrations commonly found within seawater(-60-80 ppb).The whole procedure takes less than 45 min to conduct,providing a highly innovative,rapid and low-cost approach for detecting Hg^2+in complex water matrices.

In-situ determination of onset lithium plating for safe Li-ion batteries

Lithium plating in working batteries has attracted wide attention in the exploration of safe energy storage. Establishing an effective and rapid early-warning method is strongly considered but quite challenging since lithium plating behavior is determined by diverse factors. In this contribution, we present a non-destructive electrochemical detection method based on transient state analysis and threeelectrode cell configuration. Through dividing the iR drop value by the current density, the as-obtained impedance quantity(R_(i)) can serve as a descriptor to describe the change of electrochemical reaction impedance on the graphite anode. The onset of lithium plating can be identified from the sharp drop of R_(i). Once the dendritic plated lithium occurs, the extra electrochemical reactions at the lithium interfaces leads to growing active area and reduced surface resistance of the anode. We proposed a protocol to operate the batteries under the limited capacity, which renders the cell with 98.2% capacity retention after 1000 cycles without lithium plating. The early-warning method has also been validated in in-situ optical microscopy batteries and practical pouch cells, providing a general but effective method for online lithium plating detection towards safe batteries.

海水磁流体中的磁声波传播

海水可以被看成是磁流体并能传播磁声波,运用建立的海洋磁流体力学模型,从理论上通过声波密度扰动驱动下的离子密度群聚现象,以及磁场脉冲驱动下的离子密度群聚现象的分析,得到磁声波的微观特征,即在地磁场的作用下,声波传播的粒子密度极大值前后会形成离子密度漂移电流,海水的盐离子将群聚到中性粒子密度极大值区,而当在海水中激励一个磁脉冲时,盐离子将产生磁场梯度漂移运动,使得盐离子向磁脉冲极大值区域群聚。在此基础上,探讨海水中无人潜航器激励磁声波的传播特征,提出通过高灵敏磁感应搜索线圈探测磁声波传播时产生的磁场扰动,从而实现一种有效的高灵敏非声探测潜航器的方法。

Thin,soft,skin-integrated electronics for real-time and wireless detectionof uricacid in sweat

Wearable sweat sensors are gaining significant attention due to their unparalleled potential for noninvasive health monitoring.Sweat,as a kind of body fluid,contains informative physiological indicators that are related to personalized health status.Advances in wearable sweat sampling and routing technologies,flexible,and stretchable materials,and wireless digital technologies have led to the development of integrated sweat sensors that are comfortable,flexible,light,and intelligent.Herein,we report a flexible and integrated wearable device via incorporating a microfluidic system and a sensing chip with skin-integrated electronic format toward in-situ monitoring of uric acid(UA)in sweat that associates with gout,cardiovascular,and renal diseases.The microfluidic system validly realizes the real-time capture perspiration from human skin.The obtained detection range is 5-200μM and the detection limit is 1.79μM,which offers an importance diagnostic method for clinical relevant lab test.The soft and flexible features of the constructed device allows it to be mounted onto nearly anywhere on the body.We tested the sweat UA in diverse subjects and various body locations during exercise,and similar trends were also observed by using a commercial UA assay kit.

海水生化需氧量快速检测技术研究进展

生化需氧量(BOD)是反映水体中有机物含量的重要指标之一,也是水质评价中广泛用于判断有机物污染程度的综合性指标。因此,监测海水BOD的含量分布和变化,对于准确分析海水水质变化,推进海洋生态环境保护,维护海洋资源的健康可持续发展具有重要意义。传统的BOD检测方法是五日培养法,但该方法存在操作过程复杂、耗时、时效性差等问题,无法及时反映海水样品的BOD含量,不适用于海水BOD的现场快速测定。总结了近年来发展的各类有望用于海水BOD快速检测的分析技术,包括传统的BOD快速检测技术、基于微生物传感器的BOD快速检测技术、基于荧光分析法的BOD快速检测技术、基于软测量法的BOD快速检测技术等,重点介绍了各种检测技术的测定原理及应用,以期为原位、实时、高分辨监测海水BOD提供了支撑。

Review of the application of in-situ sensing techniques to address the tea growth characteristics from leaf to field

The tea plant is a valuable and evergreen crop that is extensively cultivated in China and many other countries.Currently,there is growing research interest in this plant.For the tea industry,it is crucial to develop rapid and non-invasive methods to evaluate tea plants in their natural environment.This article provides a comprehensive overview of non-invasive sensing techniques used for in-situ detection of tea plants.The topics covered include leaf,canopy,and field-level assessments,as well as statistical analysis techniques and characteristics specific to the research.Non-invasive testing technology is primarily used for monitoring and predicting tea pests and diseases,monitoring quality,and nutrients,determining tenderness and grade,identifying tea plant varieties,automatically detecting,and identifying tea buds,monitoring tea plant growth,and extracting tea garden areas through remote sensing.It also helps to evaluate planting suitability,assess disasters,and estimate yields.Additionally,the article examines the challenges and prospects of emerging techniques aimed at resolving the in-situ detection problem for tea plants.It can assist researchers and producers in comprehensively understanding the tea environment,quality characteristics,and growth process,thereby enhancing tea production quality,and fostering tea industry development.

海水中6种均三氮苯类除草剂同步检测方法建立

本研究建立了海水中莠去津、莠灭净、西玛津、扑草净、氰草津和异戊乙净6种均三氮苯类除草剂农药残留的液相色谱-串联质谱(LC-MS/MS)同步检测方法。使用乙腈提取海水中均三氮苯类农药,采用新型纳米材料制作的SPE小柱对提取液进行净化,利用液相色谱-串联质谱法进行分析,外标法定量。结果显示,6种均三氮苯类除草剂在0.20、1.00和20.00μg/L水平下的平均添加回收率为65.40%~97.40%,相对标准偏差为0.89%~5.86%,方法定量限(灵敏度)为0.03~0.05μg/L。本研究建立的方法可用于海水中6种均三氮苯类除草剂的同步检测,具有快速便捷、准确可靠的优点。

分光光度法测定海水中叶绿素a的方法研究

海水中叶绿素a指标是评价海水富营养化的一个重要参数,现行标准GB 17378.7—2007《海洋监测规范》中规定海水中叶绿素a的两种分析方法,分别是荧光分光光度法和分光光度法,但是这两种分析方法都没明确检出限、精密度和准确度等方法特征性指标。以GB 17378.7—2007《海洋监测规范》和HJ 168—2020《环境监测分析方法标准制订技术导则》等为依据,采用分光光度法,通过试验确立分光光度法分析海水中叶绿素a的检出限等特征性指标数据,以方便日常工作数据填报以及为其他实验室分析人员提供参考。

海洋底水原位探测技术与中国南海天然气水合物勘探

在分析研究国内外海洋底水原位探测技术的前提下,详细阐述了自主研发的"海水溶解气甲烷原位探测技术成果"的研发思路、关键技术和与国外技术的区别;结合该技术在我国南海北部水合物赋存区获得海洋底水原位甲烷测试数据以及现有分层海水技术在南海北部表层海水和台西南盆地底层海水中甲烷测试数据,进行了水合物勘探中分层海水甲烷指标地球化学特征和不同海水测量方法技术在天然气水合物勘探中指示作用的研究和评价,旨在为天然气水合物中海水地球化学勘探方法的选择和发展方向提供参考依据。结果表明:(1)表层海水溶解气甲烷异常在区域水合物远景区中具有10~50nmol·L^(-1)的绝对甲烷浓度和面积较大(上千km^2)的区域地球化学特征;(2)底层海水甲烷异常背景值一般具有100nmol·L^(-1)以上的绝对甲烷浓度和面积较确定的局部地球化学异常特征;(3)海洋底水原位甲烷地球化学异常数据在水合物赋存区上的异常具有300~800nmol·L^(-1)的绝对甲烷浓度并具有高衬度异常特征。勘探技术成果显示:(1)常规技术和CTD技术获取的表层海水异常能够筛选水合物勘探远景区;(2)底水原位技术和台湾的岩心钻探技术(core top water)获取的底水地球化学异常与地下烃类聚集体渗漏相关,并有以生物成因气为主的同位素特征,因此该异常能够显示与水合物相关的甲烷渗漏地,为水合物赋存区段的识别提供依据。海水原位地球化学勘探技术在水合物海水地球化学勘探中具有广阔的应用前景。

海水中重金属检测方法研究及治理技术探索

文章介绍了海水中重金属的检测方法的工作原理、研究进展及其优缺点,包括原子吸收光谱法、原子荧光法、阳极溶出伏安法、催化极谱法、电感耦合等离子体质谱法及其他方法;概述了水体中重金属污染防治的物理法、化学法、生物法和膜分离技术等4种常用方法,提出了海水中重金属污染治理方法建议。

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。

海水就地测量探测器探测效率的MonteCarlo研究

为研制用于海洋放射性监测（特别是核电海域）的海水中就地7能谱仪，利用MonteCarlo程序MCNP，采用分层抽样、结果加权叠加的方法，模拟了海水中NaI（T1）、HPGe、CdZnTe、LaBr等探测器在理想状况下对几种有关7射线的能谱，并分析计算出以上各探测器对海水中137CS、60Co、56Mn、40K等放射性核素的探测效率、有效探测距离。结果表明，各探测器对γ放射性核素的有效探测距离约为20～40cm，具体数值与探测器种类和γ射线能量有关。综合探测效率和能量分辨率而言，LaBr探测器具有最好的实际应用价值。该结果为实际的海水中就地γ能谱仪的探测器选择和应用提供了重要参考。

海洋金属腐蚀监检测电化学传感器的研制

研制了一种适用于材料海水腐蚀试验站网金属挂片腐蚀检测的电化学传感器,设计了弹性固定装置,并应用所研制的传感器,对于碳钢试片在3.5％NaCl溶液中进行了测试,结果表明,传感器能够如实地反映试片的腐蚀状况。

海水中苯扎溴铵除藻剂的紫外可见分光光度法测定

Benzalkonium bromide is a high-efficiency algaecide.Its concentration in seawater was measured by the method of spectrophotometer. The results indicated that the deposition appeared if the concentration of benzalkonium bromide in seawater was more than 50mg·L -1,and affected the detection of benzalkonium bromide.But,there was a good linear relationship between concentration and absorbance when the concentration was lower than 50mg·L -1 (R 2=0.9996). Therefore,spectrophotometer could be used to detect benzalkonium bromide in seawater.

海洋低频电场探测电极性能表征

为探测海洋环境中的低频电场,制备了固态Ag/AgCl电极,通过对电极稳定性、灵敏度及其对已知电场信号响应特性的考察,探讨了其用于海水环境中电场传感器探测电极的可行性,并用电化学交流阻抗的方法研究了不同频率范围时电极的界面反应特性。结果表明,在海水环境中,Ag/AgCl电极稳定性好,灵敏度高,频率响应特性好,能够较准确地探测海水中一定频率范围的交流电场信号,可作为海洋环境中电场传感器的探测电极。受电极界面反应影响,电极在探测信号时对应着一个最佳工作频率范围。

碳钢试片实海电化学检测与腐蚀规律的相关性

By using polarization resistance measurement and electrochemical impedance spectroscopy(EIS),in field corrosion electrochemical detections of Q235 carbon steel and Q235 ultrafine grained steel immersed samples in Zhoushan Marine Corrosion Test Station were performed for 4 years.Dynamic corrosion data during exposure were obtained.Electrochemical detection results reflected not only the corrosion modalities and corrosion rates of the samples,but also the direct influence of marine environmental factors on the corrosion behavior.Seawater temperature was the major factor influencing the corrosion behaviors of carbon steels,and corrosion rates of these samples increased with increasing seawater temperature.The influence of seawater velocity and orientation of flow was less than that of temperature.

反渗透膜组件检测实验平台一体化控制系统

以反渗透膜组件检测实验平台为依托,研究适用于海水淡化系列实验平台的典型控制系统。实验平台的参数采集采用高精度智能仪表和就地仪表相结合,其控制系统集控制、检测、记录、报警为一体,具备开放性及可扩展性,满足不同实验的需要。结果表明:系统运行状况良好,系统的可靠性、先进性均能达到预期指标,一体化控制系统完全适用于海水淡化系列实验平台。