漫反射光谱手工与机器制样方法测试结果与对比分析

矿物含量及其变化有可能蕴藏着环境信息。赤铁矿和针铁矿是常见的两种化合物,在各种类型的沉积物中基本都有分布。在古气候研究中,赤铁矿和针铁矿的含量变化可以用来指示气候的干湿变化。漫反射光谱方法(DRS)可以进行赤铁矿和针铁矿含量测算,具有灵敏度高、速度快、准确度高等特点。这种方法虽然很实用,但是对于样品量比较大的研究来说,其手工磨样速度比较慢,而用机器研磨则会大幅提高样品制备效率,但是机器研磨是否会对分析结果产生影响尚未有研究报道。本文对30个河流相和湖泊相样品进行了漫反射光谱对比分析实验,发现手工和机器磨样在磁性矿物浓度上的变化趋势基本一致,但是两者之间存在一定的差异。因此,如果研究目的是希望从整体变化趋势来反演气候变化的过程,用机器研磨方法可以达到要求且效率明显提高;如果是进行浓度含量等其它方面的研究,则传统的手工方法是优先选择。

Diffuse reflection spectrum comparative analysis between the handmade and machine grinding samples

Background, aim, and scope The concentration and change of mineral species may contain environmental information. Hematite and goethite are common iron-containing compound and nearly distributed in all of the sediments. In research on paleoclimate, content change of hematite and goethite could reflect dry and wet climate change. Diffuse reflection spectrum (DRS) method is generally used to measure the relative content of hematite and goethite, because of its advantages, such as high sensitivity, high speed, high precision and so on. However, we have to grind samples by hand before measuring and this is time-consuming with regard to researchers who have large number of samples. Machine grinding method is high productive but we have no knowledge about whether it would influence the DRS results. Materials and methods Here, we selected 30 fluvial or lacustrine samples for magnetic minerals and DRS comparative analysis. Results The goethite concentration has a minor difference, however, the general trend is nearly the same although there are differences about concentration. Discussion The concentration of the handmade is a bit high than machine grinding at some points. This may be led by the goethite mineral change which is possibly generated by the machine grinding transient temperature exceeded the goethite Currie temperature after rejecting other factors. Conclusions Machine grinding method is priority if we just invert the climate change processes by general trend and this method is highly efficient. On the other hand, handmade method is priority if we do research about the content and so forth. Recommendations and perspectives Machine grinding method is priority if we just invert the climate change processes by general trend and this method is highly efficient. On the other hand, handmade method is priority if we do research about the content and so forth.