共查询到20条相似文献，搜索用时 140 毫秒
1.
参考《海洋监测规范第6部分:生物体分析》(GB17378.6-1998)的规范方法,采用单一HNO3-HClO4常压方法消化贻贝成分分析分析标准物质(GBW08571)。取样量为0.500g时,在加热温度为160℃～210℃,加入10mL HNO3、2mLHClO4,加盖加热7h左右,最后的样品消化液赶酸赶净的条件下,样品消化液直接以原子吸收分光光度计测定,其中Cu,Pb,Zn,Cd,Cr的测定值都在标准值范围之内。并着重对比温度对消化效果的影响以及Cu,Cd以火焰法与无火焰法测定的差别。 相似文献
2.
3.
本文报道了利用能量色散X射线荧光光谱测定海洋沉积物中微量元素V,Cr,Y,Zr和Nb的分析方法。该方法简便、快速,测试的精密度和准确度较好,满足了目前海洋沉积物样品的分析需要。 相似文献
4.
5.
6.
以海洋沉积物中镉检测结果为例分析报道了近期对我国56个海洋行业监测检测实验室参加的能力验证结果进行了评价,并对测定结果异常进行了原因分析,这对能力验证活动组织者和参加者完善能力验证方式及实际检测提供帮助。此次能力验证的结果表明,提供海洋沉积物中Cd测定有效检测数据的55个实验室,其中满意、可疑以及不满意的实验室数目分别为42、11和2个,分别占总数的76.4%、20.0%和3.6%;测定结果达不到要求的原因主要来自于技术人员的操作水平和对样品制备及设备的把控能力,对检测技术人员系统地训练和培训是提升实验室检测准确度的关键。 相似文献
7.
准确测定海洋沉积物中重金属元素的含量,对于健康海洋的监测、维护和治理具有重要的指导意义。本文报道了电感耦合等离子体质谱法(ICP-MS)同时测定海洋沉积物中铜、锌、铅和镉四种元素微波密闭消解条件的正交试验优化结果。运用正交试验法,选取L16(45)正交表,按五因素四水平安排试验,研究不同酸体系和配比下,以及不同微波消解条件下沉积物样品的消解效果。经极差分析及方差分析后,得到海洋沉积物样品在称样量为0.05 g左右(精确到±0.000 1 g)情况下,最佳消解条件为HNO3(体积分数69%)用量6.0 mL、H_2O_2(体积分数30%)用量3.0 mL、HF(体积分数49%)用量3.0 mL、第三步程序消解温度190℃、保温时间15min。结果表明,正交优化后的方法准确度高,对三种有证海洋沉积物标准物质的测试均在标准值范围内;回收率好,各元素回收率在91.52%～107.55%之间;精密度高,重复性好,重复性的相对标准偏差为1.29%～8.21%;方法检出限低,各元素方法定量下限为0.005～0.057μg/g。该方法准确可靠,满足海洋沉积物样品中铜、锌、铅和镉等元素含量准确测定的测试需求。 相似文献
8.
9.
10.
磷作为海洋浮游生物生长必需营养元素之一,其准确测定对海洋生态系统元素循环过程的研究具有重要意义。目前,文献中对于海洋浮游生物中总磷的测定方法报道不多。由于海洋浮游生物生存的高盐海洋环境,高盐基体的存在导致常规检测方法不能准确测定磷的含量。为剔除高盐基体效应及干扰,本文运用微波密闭消解预处理样品,采用电感耦合等离子体发射光谱法(ICP-OES)联合标准加入法建立工作曲线,同时结合样品的特异性,对ICP-OES分析谱线、射频功率、雾化气流速、观测高度、蠕动泵泵速和观测方式等仪器参数进行优化,构建确定了准确测定海洋浮游生物中总磷的优化条件和技术流程。实验结果显示, ICP-OES最佳工作条件为分析谱线P213.617 nm,射频功率1 300 W,雾化气流量0.8 L/min,观测高度14mm,进样泵速1.5 m L/min,观测方式轴向。标准加入法标准曲线相关系数大于0.999,相对标准偏差为1.36%~1.67%,加标回收率为92.6%~94.3%,方法检出限为0.010 mg/L,检测结果具有较高的准确度和精密度,可为海洋浮游生物及其它高基体生物样品中磷含量的准确测定提供技术支持。 相似文献
11.
An intercomparison study of voltammetric and atomic absorption spectrometric methods for determining cadmium, lead and copper in seawater samples was conducted. The voltammetric approach utilizes differential pulse anodic stripping voltammetry using a rotating, glassy carbon, mercury film electrode under conditions developed to minimize contamination sources and to enhance sensitivity for seawater matrices. The atomic absorption approach involves a concentration step using either an organic solvent extraction of metal dithiocarbamate chelates or a Chelex-100 column with detection by graphite furnace atomic absorption spectrometry. Similar and consistent results were obtained using both methods for the three trace metals studied on a wide range of natural seawater samples. Both methods are comparable in sensitivity for cadmium and copper, however the voltammetric method is better suited for the analysis of lead in seawater because of its enhanced sensitivity and low blank. An advantage of the voltammetric approach is its amenability towards real-time shipboard analysis. 相似文献
12.
本研究建立了AMS(Accelerator mass spectrum,加速器质谱)测定海水中129 I的气载分离制样方法:对加入载体的海水样品进行氧化还原处理,在加热的条件下将生成的单质碘吹出,并使用吸收装置吸收,后经阴离子交换树脂富集纯化,最后生成用于AMS分析的AgI沉淀,本方法全程回收率50%~70%,在相对密闭的体系中进行,减少了碘的损失,相对于萃取-反萃取的制样方法具有可操作性强,避免有机试剂使用等优点,可用于固态、液态和气态样品中129 I的AMS分析制样。 相似文献
13.
电解富集-液体闪烁计数法测量北极海水中氚活度 总被引：1，自引：1，他引：0
A method of measuring the tritium in seawater based on electrolytic enrichment and ultra-low background liquid scintillation counting techniques was established. The different factors influencing the detection limit were studied, including the counting time, the electrolytic volume of the seawater samples, the selection of background water, scintillation solution and their ratio. After optimizing the parameters and electrolyzing 350 mL volume of samples, the detection limit of the method was as low as 0.10 Bq/L. In order to test the optimization of system for this method, of the 84 seawater samples collected from the Arctic Ocean we measured, 92% were above the detection limit(the activity of this samples ranged from 0.10 Bq/L to 1.44 Bq/L with an average of(0.30±0.24) Bq/L).In future research, if we need to accurately measure the tritium activity in samples, the volume of the electrolytic samples will be increased to further reduce the minimum detectable activity. 相似文献
14.
An energy conversion system based on deep-sea pressure 总被引：1，自引：0，他引：1
A novel seawater pressure energy conversion system that utilizes seawater pressure to generate electricity has been studied in this paper. The energy conversion system utilizes the pressure difference between the pressurized seawater and the empty pressure container to drive hydraulic motor and the coaxially coupled generator to generate electric power. The output electric energy is recorded by the data logger throughout the process. In the current study, technical analysis is performed with the emphasis on conversion efficiency between seawater pressure energy and output electric energy. The analysis is conducted at various pressure differences through the throttle valve so as to obtain maximum conversion efficiency. Research shows that the optimum pressure difference through the throttle valve and the maximum conversion efficiency can be theoretically calculated when the properties of the conversion system are given. Simulation results have demonstrated the influence of pressure difference on conversion efficiency. The test apparatus has been designed, built and tested in 2004. It successfully generated electric energy of approximately 0.85 kW h at the depth of 2400 m with empty pressure container's holding capacity of 200 L in the voyage “DY105-16” in South China Sea on June 12, 2004. The actual conversion efficiency from seawater pressure energy to electric energy reaches as high as 63.8% which is attractive for underwater equipments. The success of the experiment has tested the feasibility of utilizing seawater pressure energy and brings a new power supply way for long-term in-situ underwater equipments. 相似文献
15.
稀土元素已越来越多地应用于示踪各类地球化学体系的物质来源与岩石矿物形成等演化过程。但在进行海水样品的稀土元素检测时，由于样品的高盐特征和稀土元素的痕量特征又使得分析具有相当的挑战性。本研究旨在从高盐的海水基质中有效分离并富集痕量的稀土元素，同时结合电感耦合等离子体质谱（Inductively Coupled Plasma Mass Spectrometry, ICP-MS）技术对海水中的稀土进行定量分析。通过对海水样品稀土元素的定量限分析、加标回收实验和梯度加标回收实验，验证了方法的准确性，评估方法的分离富集效率。通过共沉淀过程中的pH比较、氢氧化钠与氨水作为共沉淀剂的比较，确定了富集过程中共沉淀剂用量、种类等影响因素。通过稀土元素配分曲线的绘制与类似样品结果进行比对，以及标准海水的检测结果，验证了方法在实际样品中的可行性。本研究探索了共沉淀富集法在分离富集海水中稀土元素的实验条件，实现高盐背景下痕量稀土的准确定量，并将其用于近岸海水与孔隙水的实际检测。 相似文献
16.
17.
A chemoreduction-purge-and-trap gas chromatographic method has been developed for the determination of trace dimethylsulfoxide (DMSO) in seawater. In the analysis procedure, DMSO was first reduced to dimethylsufide (DMS) by sodium borohydride and then the produced DMS was analyzed using the purge-and-trap technique coupled with gas chromatographic separation and flame photometric detection. Under the optimum conditions, 97% DMSO was reduced in the standard solution samples with a standard deviation of 5% (n=5). The detection limit of DMSO was 2.7 pmol of sulfur, corresponding to a concentration of 0.75 nmol/L for a 40 ml sample. This method was applied to determine the dissolved DMSO (DMSOd) and particulate DMSO (DMSOp) concentrations in the surface seawater of the Jiaozhou Bay, and the results showed that the DMSOd and DMSOp concentrations varied from 16.8 to 921.1 nmol/L (mean:165.2 nmol/L) and from 8.0 to 162.4 nmol/L (mean:57.7 nmol/L), respectively. The high concentrations of DMSOp were generally found in productive regions. Consequently, a significant correlation was found between the concentrations of DMSOp and chlorophyll a, suggesting that phytoplankton biomass might play an important role in controlling the distribution of DMSOp in the bay. Moreover, in the study area, the concentrations of DMSOd were significantly correlated with the levels of DMS, implying that the production of DMSOd is mainly via photochemical and biological oxidation of DMS. 相似文献
18.
This article deals with a new method of analysing in seawater, i. e. the uranium is concentrated with an aqueous suspension of basic zinc carbonate, subsequently isolated and determined by extraction-photometric method. In concentrating uranium such factors as stirring time, amount of adsorbent used, acidity of seawater were studied and conditions suitable for analysis were found. This method is simple, accurate and good in reproducibility. It is not necessary to adjust the pH of seawater before analysis. This technique can also be applied to determination of uranium in river or lake. 相似文献
19.
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. 相似文献
20.
镀铜镉柱还原——重氮偶氮染色法在检测海水领域具有重要的位置,算法的不断创新优化成为海水水质检测质量的的关键。本研究以硝酸钾作为标准溶液,海水作溶剂做相关实验,并且在实际海水检测应用中得到良好的效果。通过对实验原理的分析及实验过程的探究,确定了本研究的最佳还原与显色条件。并采用偏最小二乘法（partial least squares regression,PLS）算法模型对实验数据进行预处理,利用浊度对其进行补偿,最终得到硝酸盐氮的最优模型。经实验结果比对,该方法确定的检测系统线性范围宽、检出限低,符合海水的快速检测要求。在此基础上设计了一套在线自动检测装置,解决了海水在线、实时监测的难题。 相似文献