trace concentration meaning in English

痕量浓度

The determination of trace concentrations of mercury in minerals is described
文章论述矿物中痕量汞的测定。
The determination of trace concentrations of mercury in mineral materials is described
译文：文章论述矿物中痕量汞的测定。
A highly sensitive chromatographic system is desirable particularly for monitoring analyte present in trace concentrations within samples
高灵敏的层析系统是一个理想的系统，特别对监测存在于样本追踪浓度的分析物。
As an example , a test with the water sample in which nitrobenzene is in a trace concentration and treated using spe for gc analysis has showed a perfect result
文章从选择固相萃取柱到萃取液进入色谱分析这样一个完整的过程，并以使用该技术萃取环境水样中的硝基苯类化合物为例，具体阐述了如何使用固相萃取技术建立一个方便实用的环境水质监测分析方法。