Accelerated Acid Digestion

EPA Contract Number: 68D98132
Title: Accelerated Acid Digestion
Investigators: Later, Douglas W.
Small Business: Mountain States Analytical Inc. (MSAI)
EPA Contact: Manager, SBIR Program
Phase: I
Project Period: September 1, 1998 through March 1, 1999
Project Amount: $69,957
RFA: Small Business Innovation Research (SBIR) - Phase I (1998) RFA Text |  Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)


Accelerated Acid Digestion (AAD) is a new sample preparation technique for digesting metals in solid matrices for analysis by instrumental techniques such as AA and ICP. The sample is placed in a closed, micro-volume acid digestion cell and digested under elevated pressure (100-500 psi) and temperature (50-180 oC) conditions using conventional acids, such as nitric and hydrochloric acids. Because the system is closed and pressurized, losses of volatile metals are minimized. Temperatures higher than the boiling point of the acid solution can be utilized, enhancing the digestion efficiency. The elevated temperature accelerates the dissolution reaction kinetic processes shortening the time required for complete digestion. Digestion acid consumption can be reduced from several hours to 5-10 minutes per sample. Controlling the acid strength, temperature, and pressure allows simulation of promulgated EPA SW-846 Methods 3050 (open- beaker, hot-plate digestion) and 3051 (microwave digestion). The most important advantages of this technique are its potential for automation and a 90% reduction in acid utilization. The AAD concepts have been proven with a prototype system. Under this SBIR project, MSAI will develop an automated, multiple-cell AAD system and an EPA SW-846 method for this technique.

Supplemental Keywords:

small business, SBIR, pollution prevention, engineering, chemistry, EPA., Scientific Discipline, Sustainable Industry/Business, cleaner production/pollution prevention, Chemistry, Technology for Sustainable Environment, Analytical Chemistry, New/Innovative technologies, waste reduction, Accelerated Acid Digestion, innovative technology, pollution prevention, innovative technologies

Progress and Final Reports:

  • Final Report