中文摘要：

高 Cr (VI ) 集中是到环境和 ecologic 系统的潜在的严肃的风险。因此，有效地在水系统监视 Cr 污染并且科学地评估它的进化趋势是必要的。一个新方法在原处，由为象案例应用一样在自然的水里估计 Cr 污染和它的地区性的进化的份量上的 Cr 同位素的分析的 tracer 技术在这份报纸被报导。基于记录文学，水里的 Cr 的分离和纯化取样的为化学药品的一个试验性的过程和它的分析方法因为由热电离团 spectrometry (提姆) 的 Cr 同位素的测量被建立。在湖北省在一家化学工厂附近收集的十一件样品被这种技术分析。这些样品表演 53Cr 珍视从 ? 1.7 ～ 7.3 并且有一从采样地点在远处增加到污染来源的一个提高的趋势。一条功能的关联追随者瑞利分别法律在样品 53Cr 价值和它 Cr 污染的程度之间被建立。这研究建议 Cr 同位素的分析是一个有效方法在地区性的水系统揭示空间分发和它 Cr 污染的进化趋势。它对根据 Cr 同位素的分别估计本地水系统的自我净化的能力因此有用。

英文摘要：

High Cr （VI） concentration is a potential serious risk to environment and ecologic system. Thus, it is essential to effectively monitor Cr contamination in water systems and scientifically evaluate its evolution trend. A new method of in-situ tracer tech- nique by Cr isotopic analysis for quantitatively estimating Cr-contamination and its regional evolution in natural waters as well as a case application are reported in this paper. Based on documented literatures, an experimental procedure for chemical separation and purification of Cr in water samples and its analytical method for Cr isotopic measurement by thermal ionization mass spectrometry （TIMS） are established. Eleven samples collected around a chemical factory in Hubei Province were analyzed by this technique. These samples show 853Cr values ranging from -1.7‰ to 7.3‰ and an elevating trend with an increasing in distance from the sampling site to pollution source. A functional correlation following Rayleigh fractionation law was established between sample＇s 853Cr value and its extent of Cr contamination. This study suggests that Cr isotopic analysis is an effective method to reveal the spatial distribution and its evolution trend of Cr contamination in the regional water system. It is thus helpful to assessing the self-purifying ability of local water system according to Cr isotopic fractionation.