Field Measurement Methods for Arsenic in Drinking Water

Water Research Foundation, 
Colorado

Field Measurement Methods for Arsenic in Drinking Water

Service Type: 
Project Highlights: 
  • Field-testing of arsenic kit with detection limit of 0.5 ppb arsenic.
  • Collection of useful operator comments regarding user friendliness of kit.
Field-testing a new arsenic kit
Carollo worked with several universities to field-test a new arsenic kit with a method detection limit of 0.5 ppb arsenic.

Utah State and Virginia Tech University worked together to develop a low cost arsenic field kit that would be portable and capable of detecting arsenic at the part per billion level. Currently, the arsenic kits offered commercially have detection limits above 10 ppb and require special laboratory equipment/conditions. After reviewing the current field methods for measuring low levels of arsenic, researchers selected an existing technique (arsine hydride generation) and modified the analytical components and method. The detection limit of this modified field technique was determined to be 0.5 ppb arsenic.

After development of the method, Carollo evaluated the technique in the field at six water utilities. Arsenic standards and groundwater samples were analyzed in the field and then sent to Utah State for re-measurement using Hydride Generation Atomic Adsorption or Inductively Couple Plasma-Mass Spectroscopy, standard technologies that are used to detect low levels of arsenic. While there was good agreement between the field method and laboratory results for about one-third of the samples measured in the field, it was apparent that users needed practice with the method to ensure consistent results. At the end of field testing, each user completed a survey that was used to determine where the method could be streamlined and improved.