Sample Preparation
The EOHSI Analytical Core Laboratory receives samples for analysis from a variety of sources including investigators from the university community and state agencies. Samples are typically received by laboratory staff; inspected for damage; logged into the laboratory data base; assigned a unique sample number; labeled properly; and stored at the appropriate temperature to await preparation and analysis. All aspects of sample receipt adhere to written Standard Operating Procedures (SOPs) and established Quality Assurance protocols. Additionally, rigorous chain-of-custody paperwork and methodology are maintained.
Samples may be received in a variety of forms including soil, water, and biological materials, as well as less typical matrices (e.g., artificial turf, garden hose, and plush children’s toys to name a few recent novel matrices). Depending on the type of sample and the method of analysis, samples will proceed along the sample preparation continuum. Typically, the Analytical Core Laboratory will analyze several QA/QC samples for each batch of samples being prepared for analysis, including preparation blanks (used to determine level of background interference); laboratory control samples (used to monitor the accuracy of the analytical method); matrix spike samples (used to evaluate the effect of the sample matrix on the accuracy of the analytical method); and sample duplicates (used to evaluate the precision of the analytical method).
Under the direction of Dr. Buckley, the CAF has twenty years of experience in developing novel analytical methods. Sample preparation methodology may include microwave assisted acid digestion for inorganic analysis and solvent extraction for organic analysis.
Prior to the analysis of a batch of samples, standard calibration curves of signal response vs. analyte concentration are generated for each analytical instrument. The number and concentration of calibration standards required to generate the calibration curve are specific to the various analytical methods. The principal analytical methods employed by the CAF include gas chromatography (GC); gas chromatography-mass spectrometry (GC-MS); and inductively coupled plasma-mass spectrometry (ICP-MS).