Sampling for particulate trace element determination using water sampling bottles: methodology and comparison to in situ pumps
Sampling for particulate trace element determination using water sampling bottles: methodology and comparison to in situ pumps
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DOI：
10.4319/lom.2012.10.367
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发表时间：
2012-05
期刊：
影响因子：
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通讯作者：
H. Planquette;R. Sherrell
中科院分区：
文献类型：
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作者：
H. Planquette;R. Sherrell
在2008-09年的GEOTRACES相互校准航行期间，对从安装在玫瑰花形的GO‐FLO瓶中过滤的5 - 10 L样品中常规采集和分析微粒痕量元素的程序进行了评价。研究了在获得颗粒痕量元素的可靠和一致分布方面的重要问题：采样瓶中颗粒沉降的影响;过滤器的类型、性能和元素空白;过滤器消化程序;以及ICP-MS分析程序。我们确定，在过滤前轻轻混合取样瓶，并将过滤时间限制在1-2小时，可最大限度地减少沉降伪影。在这些测试中，0.45 µm聚砜过滤器具有最佳的颗粒负载特性、空白和物理属性，适合海上常规使用。最大过滤器装载量要求在公海台站使用25毫米过滤器，这对实现低空白校正至关重要;大多数元素对工艺过滤器空白的校正< 10%。在硝酸和氢氟酸中加热消化是必要的，以实现所有颗粒元素的溶解。通过重复取样评价的重现性总体上非常好，分析重现性< ± 4%。使用优化的方法，GO-FLO-filtered颗粒元素剖面中Al、P、Mn、Fe、Co、Cu、Zn、Cd和Ba的含量与SAFe站（北卡罗来纳州东部）现场泵送收集的含量相当。太平洋）和圣巴巴拉盆地（沿海加州，美国），没有系统性偏差的采样系统。这里评估的方法表明，低容量方法可用于确定海洋流域尺度水文巡航中颗粒微量元素的分布，具有效率，精度和高空间分辨率。
Procedures for routine collection and analysis of particulate trace elements from 5‐10 L samples filtered from rosette‐mounted GO‐FLO bottles were evaluated during the GEOTRACES intercalibration cruises of 2008–09. Issues important in obtaining reliable and consistent distributions of particulate trace elements were investigated: the effect of particle settling in sampling bottles; type, performance, and elemental blanks of filters; filter digestion procedures; and ICP‐MS analytical procedures. We determined that gentle mixing of sampling bottles just before filtration, and limiting filtration time to 1–2 h, minimizes settling artifacts. Among those tested, 0.45 µm polysulfone filters had the best particle loading characteristics, blanks, and physical attributes for routine use at sea. Maximum filter loading, requiring use of 25 mm filters at open ocean stations, was critical to achieve low blank corrections; most elements had < 10% correction for a process filter blank. Heated digestion in nitric and hydrofluoric acids was necessary to effect dissolution of all particulate elements. Reproducibility, evaluated through replicate sampling, is very good overall, and analytical reproducibility was < ±4%. Using the optimized methods, GO‐FLO—filtered particulate elemental profiles for Al, P, Mn, Fe, Co, Cu, Zn, Cd, and Ba compared well to those collected by in situ pumping at the SAFe station (eastern N. Pacific) and at Santa Barbara Basin (coastal California, USA), with no systematic bias for either sampling system. The methodologies evaluated here demonstrate that low‐volume methods can be used to determine distributions of particulate trace elements on ocean basin‐scale hydrographic cruises, with efficiency, precision, and high spatial resolution.