Determination of Hexavalent Chromium in Drinking Water Using Segmented Flow Analysis

Poster-Other
Poster Presentation

Prepared by , B. Sanchez

Contact Information: [email protected]; 559-707-2296


ABSTRACT

Segmented Flow Analysis (FIA) is a cost and time effective alternative procedure for a wide range of analytical techniques, specifically hexavalent chromium (Cr VI) in drinking water. It is advantageous to have alternative methods other than ion chromatography (EPA 218.6 or 218.7), which are the approved methods for the determination of Cr VI in drinking water. The use of FIA to determine Cr VI is substantially quicker than other methods. It has a run time of 120 seconds per sample and can consistently produce low-level results. The goal of this study is to present information about this method and the capabilities of the instrument that could lead to a broader acceptance of this method for drinking water analysis. This method was initially explored as California and other states begin to develop more stringent guidelines for hexavalent chromium. While the use of flow analysis is approved for determining Cr VI in wastewater, the use of this methodology is not yet approved by the EPA for drinking water. After the acceptance of Cr VI for wastewater (Standard Method 3500 Cr B) in our laboratory, the goal of acquiring acceptance for drinking water was initiated. Method detection limit studies, initial demonstration of accuracy and precision and total reporting limit verification were competed. This resulted in determining that the MDL for Cr VI is 0.035ug/L, with a reporting level of 0.05ug/L. In California, the maximum contamination level is 10ug/L and the required detection limit for reporting is currently 1ug/L; both are well above the method detection limit and the reporting level acquired when using the FIA system. While this method is not yet approved, it is vital to bring attention to this possible alternative procedure because it has the capability to drastically improve efficiency and lower costs.