||Direct/delayed response project : soil characterization comparison /
Fenstermaker, L. K. ;
Byers, G. E. ;
Starks, T. H. ;
Miah, M. J. ;
Palmer, C. J.
||Lockheed Engineering and Sciences Co., Inc., Las Vegas, NV. Environmental Programs Office.;Environmental Monitoring Systems Lab., Las Vegas, NV.
|| U.S. Environmental Protection Agency, Office of Research and Development, Environmental Monitoring Systems Laboratory ; Distributed by the National Technical Information Service,
Acid deposition--United States--Measurement. ;
Soil acidity--United States--Measurement. ;
Acid deposition--Measurement. ;
Soil surveys ;
Interlaboratory comparison ;
Land pollution ;
Data analysis ;
Soil analysis ;
Quality assurance ;
Cation exchanging ;
Water pollution ;
Acid rain ;
Direct/Delayed Response Project
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
||371 pages ; 28 cm
A large amount of soil characterization data has been collected as a component of the Direct/Delayed Response Project (DDRP) in the acid rain Aquatic Effects Research Program. An interlaboratory comparison study was undertaken to identify the comparability of the data to that obtained from representative soil characterization laboratories. Participating laboratories were selected at random from four regions of the U.S. and two regions of Canada. Two original DDRP contract laboratories also participated. Duplicate samples of six soil audit materials and two liquid soil extracts were sent to each of the laboratories in two separate batches. Laboratories used their own protocols to perform the analyses requested except for the contract laboratories which followed the DDRP protocol. Liquid audits were used in an effort to identify if interlaboratory differences were due to extraction procedures or chemical measurements. A component of the variability in the results was attributed to differences in the methods used such as soil/solution ratios, extractants or extraction procedures. The largest number of different methods used was for the measurement of cation exchange capacity. The results between the DDRP soil survey data and the study's results were compared using Youden-pair plots. In addition, standard statistical tests were performed. Overall, the DDRP data were comparable to the data from the study. However, out of the total 141 comparisons involving results from six or more laboratories, the results from the two contract laboratories did not meet the comparison criteria in 19 cases. Since there was never a case in which both contract laboratories failed, it would appear that the 19 cases which were not comparable were due to random analytical errors, incorrectly reported results, or misapplication of DDRP protocol.
"EPA/600/4-91/008"--Cover. "February 1992"--Cover. "Project officers L.J. Blume and D.T. Heggem." "Cooperative agreement no. CR814701-01." "Contract no. 68-03-3249." Includes bibliographical references. Microfiche.