泛滥平原沉积物标准物质研制

泛滥平原沉积物能代表流域内元素的平均分布规律并具有普遍的适用性,是地球化学填图工作的重要介质。目前国际上尚无泛滥平原沉积物标准物质,国外相似标准物质的研制注重于环境方面,定值成分较少;我国同类的土壤和水系沉积物标准物质受限于不同工作需要,研制目的各不相同,且多数标准物质不足。为满足需求,本文研制了长江流域、赣江流域、汉水流域、淮河流域、黄河流域、海河流域、黑龙江流域共7个泛滥平原沉积物国家一级标准物质(编号为GBW07385～GBW07391)。此系列标准物质采用X射线荧光光谱压片法测试了26种成分,主量成分的RSD小于1%,微量元素的RSD约为2%,所有成分的RSD均小于7%,方差检验的F值均小于临界值F0. 05(24,25)=1. 96,表明样品的均匀性良好。在23个月的考察期内,检验的24种成分未发现统计学意义的明显变化,证明样品的稳定性良好。由全国13家实验室采用不同原理的、可靠的多种分析方法共同完成了73种元素和化合物共511个特性成分的定值测试,除GBW07386和GBW07388的CO2未能赋值外,其余494个特性成分给出了认定值与不确定度,15个特性成分给出了参考值,是我国同类标准物质定值最为齐全的一个系列。该系列标准物质代表了各自流域元素的背景含量,适用于多目标地球化学调查、土地质量地球化学调查等样品的分析质量监控,亦可用作环境、农业等领域相关样品测试的量值和质量监控标准。

Preparation of Seven Certified Reference Materials for Floodplain Sediments

BACKGROUND:Floodplain sediment, which is an important sampling media for geochemical mapping, can represent the average distribution of elements in the basins and has universal applicability. At present, there is no floodplain sediment reference material in the world. The development of similar standards in foreign countries focuses on the environment, and there are fewer fixed components. The same standards for soil and river sediments in China are limited by different work needs, and the development aims are different. Most of the standard substances are insufficient.
OBJECTIVES:To develop 7 national first-level reference materials for floodplain sediments in the Yangtze River, Gan River, Han River, Huaihe River, Yellow River, Haihe River and Heilongjiang River (GBW07385-GBW07391).CANDIDATES CHARACTERISTICS:Sample GSS-29 is the floodplain sediment of the Yangtze River. It is grayish yellow and contains high contents of silty. GSS-30 is the floodplain sediment of the Gan River, which is sub clay with relatively fine particle size. GSS-31 is the floodplain sediment of the Han River, which is gray-black, fine-grained and contains relatively high contents of organic matter. GSS-32 is the floodplain sediment of the Huaihe River, which is grey-black, fine-grained and clay-like. GSS-33 is the floodplain sediment of the Yellow River, which is black clay with relatively fine grain size and relatively high contents of organic matter. GSS-34 is the floodplain sediment of the Haihe River, which is sub clay with a relatively fine grain size and high content of clay formed in block. GSS-35 is the floodplain sediment of the Heilongjiang River, which is black and loose, with a relatively fine grain size and high content of clay where some was formed in block.
METHODS:A series of reference materials was tested using X-ray Fluorescence Spectrometry to measure 26 components. The RSD of the main components was less than 1%, the RSD of minor elements was 2% and the RSD of trace components was less than 5%. The F value of the variance test was less than the list threshold F_0.05(24,25)=1.96, indicating that all seven materials were homogeneous. No significant statistical changes were found in the 24 elements and compounds tested within 23 months, indicating that the stability of these materials were stable. Thirteen laboratories have participated in this inter-laboratory program, and have adopted various reliable analytical methods based on different principles to set the values.
RESULTS:A total of 511 characteristic components, including 73 elements and compounds, have been tested. In addition to the CO₂ values of GBW07386 and GBW07388 that cannot be assigned, the remaining 494 characteristic components are given the certified value and uncertainty, and 15 characteristic components are given. The trace elements in GSS-29 have the mostly high background contents. The trace elements in GSS-30 have medium background values, and the contents of W, Sn and Mo are relatively high. The contents of Cd and Mo in GSS-31 are relatively high. The trace elements in GSS-32 have low background contents, and the contents of Cd, Hg, Mo, N, S and P are lower than the background level. The content of Hg in GSS-33 is very low. The trace elements in GSS-34 have the mostly medium and high background levels, and the contents of F, Cl and Br are relatively high. The organic matter content of GSS-35 is relatively high.
CONCLUSIONS:The seven reference materials for floodplain sediments have been certified by the General Administration of Quality Supervision, Inspection and Quarantine of the People''s Republic of China (AQSIQ) in 2017. This series of floodplain sediment certified reference materials (GBW07385-GBW07391) represents the background values of the elements of each corresponding drainage area. It can be used for monitoring the quality of geochemical sample analysis or the quality of sample analysis in other fields, such as geology, environment, and agriculture.