A new technique for ppt levels of mercury in air & water

Accepted for presentation at #acsBoston on the American Chemical Society Division of Environmental Chemistry August 16-20 2015 at both SCI-MIX and ENVR posters ABSTRACT SYMPOSIUM NAME: SCI-MIX and General Posters

ABSTRACT SYMPOSIUM PROGRAM AREA NAME: [ENVR] Division of Environmental Chemistry

CONTROL ID: 2253367

PRESENTATION TYPE: Poster

TITLE: A new technique for ppt levels of mercury in air and  water

AUTHORS (FIRST NAME, LAST NAME): John N. Driscoll1, Jennifer L. Maclachlan1

INSTITUTIONS (ALL): 1. PID Analyzers, LLC, Sandwich, MA, United States.

ABSTRACT BODY:  Abstract: We reported recently that the photoionization detector (PID) with a 10.6 eV lamp responds to mercury (Hg) with detection limits of 10 ppb. The PID is a non-specific method for Hg since it also has a strong response to VOC’s. Other non-specific methods like UV absorbance and atomic fluorescence use a gold pre concentrator (GPC) to collect Hg by forming a Au/Hg amalgam at room temperature, purging to remove water and VOC’s then rapidly heating to 500oC to release the Hg. We have found that this same technique can be coupled to the PID to produce an analyzer with detection limits in the ppt range. For Hg in water, the hydride method can be used to reduce Hg+2 to form elemental mercury that is concentrated on a GPC and detected by PID. This method has low ppt detection limits. This presentation will describe the method and results in detail.

Pittcon 2015

A New Method for the Analysis of ppb Levels of Mercury in Air and Water

Accepted for presentation at Pittcon 2015
March 8-12, 2015
New Orleans, LA
Abstract Number: 1100 - 6
Session 1100 - Environmental - Portable Instrumentation
Day and Time: 0 2015 10:25 AM
Room 256


Authors: Jack Driscoll and Jennifer Maclachlan, PID Analyzers, LLC

Methodology:	Other, gold film/photoionization
Application:	Environmental
Primary Focus:	Application
Title:	A New Method for the Analysis of ppb Levels of Mercury in Air and Water
Keywords:	Air Elemental Analysis Environmental Analysis Water Nonspecific methods such as UV absorbance or fluorescence have been successfully used for the analysis of ppb concentrations of mercury in air and water. The unique amalgamation of mercury with gold and silver makes this possible. .Air samples are collected and only the mercury is reacted with the gold surface. Any impurities are purged through, then the amalgam is heated to desorb the mercury which is measured by the detector.  We have used a very sensitive but nonspecific photoionization detector (PID) with a 10.6 eV lamp to measure mercury that has an ionization potential of 10.43 eV. The chemistry of the gold/mercury amalgam makes this method specific for mercury. The Permissible Exposure Limit (PEL) for Hg is 0.05 mg/m3 (0.408 ppm). Mercury permeation tubes were used to generate levels from 0.02 to 1 ppm. Preliminary data indicates a detection limit of > 10 ppb of Hg for the gold film photoionization detector (GFPID) analysis. Water samples are analyzed using hydride generation with sodium borahydride to reduce the inorganic salts to elemental mercury that is efficiently detected by the PID. The EPA MCL for mercury in drinking water is 2 ppb. The  detection limit for Hg in water by hydride generation GFPID was 0.2 ppb.