Standard soil sample preparation error and comparison of portable XRF to laboratory AA analytical results

A method to quantify and report error in the preparation and analysis of standard samples is developed. The process of constructing standard samples for use in work involving metal contamination of soil is reviewed. Error in the constructed concentration is determined as a function of electronic balance accuracy and precision, sample mass, and desired concentration. Typical results are presented for the construction of a suite of samples. Distribution of error in the analysis of standard sample concentrations by field portable X-ray fluorescence and laboratory atomic absorption is also investigated using six populations of constructed standards involving lead contamination. Typical construction error and observed analytical error are reported.