skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Determination of the Efficiency of Mixed-Acid Digestions of Sediments

Abstract

Mixed-acid digestion is a method often used for the determination of elemental analysis of sediment samples. It is crucial that efficiency details associated with the digestion method be well understood on an element by element basis. Battelle’s Marine Sciences Laboratory Standard Operating Procedure for Sediment Mixed-Acid Digestions was modified to identify conditions which produce optimal recovery of elements. The parameters that were adjusted for testing were mass of sediment, mixed-acid volume, mixed-acid composition and digestion time. Digestion involves treatment of the sediment sample with mixed-acid mixtures at 135º C ± 10º in a Teflon® digestion bomb. Typical analytical methods include Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma – Mass Spectrometry (ICP-MS). Initial experiments involved determining the optimal ratio of acid volume to mass of sediment. Experiments were designed to identify the point at which insufficient acid was used to effectively digest a given mass of sediment. When the mass of sediment was varied between 0.2 and 1.0 gram using a 4 mL aqua regia acid mixture (3 mL hydrochloric acid and 1 mL nitric acid), there was no effect on the recovery of the elements Al, Ba, Ca, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb,more » Sr, Ti, V, and Zn. The next experiments focused on a time study to resolve the shortest digestive time for optimal elemental recovery. Two masses of sediment were investigated, 0.25 and 0.7 g, again utilizing aqua regia digestion (4 mL). Maximum recovery was reached after 4 hours of digestion; additional digestion time released no or only minimal amounts of elements from the sediments. The final set of experiments was designed to identify optimal conditions for the total digestion of sediment using a mixture of hydrochloric acid, nitric acid, hydrofluoric acid, hydrogen peroxide, and boric acid. These experiments were designed to determine the optimal volume of hydrofluoric acid needed to achieve a total digestion. Utilizing two masses of sediment 0.25 and 0.5 g and varying the volume of hydrofluoric acid and boric acid. Total digestion was achieved with a minimum volume of 0.5 mL hydrofluoric acid and a .25 g of sediment. Future experiments incorporating the findings in these experiments will be executed using a heated carbon block as the source for thermal energy.« less

Authors:
;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
993373
Report Number(s):
PNNL-SA-51400
TRN: US201023%%220
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Undergraduate Research, VII:150; Journal Volume: 7
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 54 ENVIRONMENTAL SCIENCES; SEDIMENTS; DISSOLUTION; AQUA REGIA; BORIC ACID; EFFICIENCY; HYDROFLUORIC ACID; HYDROGEN PEROXIDE; MIXTURES; PERFORMANCE TESTING; MULTI-ELEMENT ANALYSIS

Citation Formats

Huerta Vazquez, Alejandra I., and Gill, Gary A. Determination of the Efficiency of Mixed-Acid Digestions of Sediments. United States: N. p., 2007. Web.
Huerta Vazquez, Alejandra I., & Gill, Gary A. Determination of the Efficiency of Mixed-Acid Digestions of Sediments. United States.
Huerta Vazquez, Alejandra I., and Gill, Gary A. Mon . "Determination of the Efficiency of Mixed-Acid Digestions of Sediments". United States. doi:.
@article{osti_993373,
title = {Determination of the Efficiency of Mixed-Acid Digestions of Sediments},
author = {Huerta Vazquez, Alejandra I. and Gill, Gary A.},
abstractNote = {Mixed-acid digestion is a method often used for the determination of elemental analysis of sediment samples. It is crucial that efficiency details associated with the digestion method be well understood on an element by element basis. Battelle’s Marine Sciences Laboratory Standard Operating Procedure for Sediment Mixed-Acid Digestions was modified to identify conditions which produce optimal recovery of elements. The parameters that were adjusted for testing were mass of sediment, mixed-acid volume, mixed-acid composition and digestion time. Digestion involves treatment of the sediment sample with mixed-acid mixtures at 135º C ± 10º in a Teflon® digestion bomb. Typical analytical methods include Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma – Mass Spectrometry (ICP-MS). Initial experiments involved determining the optimal ratio of acid volume to mass of sediment. Experiments were designed to identify the point at which insufficient acid was used to effectively digest a given mass of sediment. When the mass of sediment was varied between 0.2 and 1.0 gram using a 4 mL aqua regia acid mixture (3 mL hydrochloric acid and 1 mL nitric acid), there was no effect on the recovery of the elements Al, Ba, Ca, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr, Ti, V, and Zn. The next experiments focused on a time study to resolve the shortest digestive time for optimal elemental recovery. Two masses of sediment were investigated, 0.25 and 0.7 g, again utilizing aqua regia digestion (4 mL). Maximum recovery was reached after 4 hours of digestion; additional digestion time released no or only minimal amounts of elements from the sediments. The final set of experiments was designed to identify optimal conditions for the total digestion of sediment using a mixture of hydrochloric acid, nitric acid, hydrofluoric acid, hydrogen peroxide, and boric acid. These experiments were designed to determine the optimal volume of hydrofluoric acid needed to achieve a total digestion. Utilizing two masses of sediment 0.25 and 0.5 g and varying the volume of hydrofluoric acid and boric acid. Total digestion was achieved with a minimum volume of 0.5 mL hydrofluoric acid and a .25 g of sediment. Future experiments incorporating the findings in these experiments will be executed using a heated carbon block as the source for thermal energy.},
doi = {},
journal = {Journal of Undergraduate Research, VII:150},
number = ,
volume = 7,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}