Sample collection information (e.g., lab prepared VOA vial, EnCore, TerraCore, etc.) must be indicated on the chain of custody and lab report. If samples are submitted with a request for low-level volatile analysis (less than 200 ug/kg), but have not been collected according to 5035 low-level specifications*, the lab must notify the client that the sample does not meet sample acceptance criteria and provide the client an opportunity to re-collect the sample.
If the client chooses not to re-collect the sample and proceed with analysis, the lab must qualify these results as “may be biased low due to the sample not being collected according to 5035-L/ 5035A-L low-level specifications.” (See 5035A, sec 8.2.1.) This will be done by a flag/qualifier affixed to the sample data.
High-level Collections (with chemical preservatives):
All samples following the high-level collection protocol must be identified on the chain of custody and lab report as collected in a water miscible solvent (such as methanol). The reporting limit for a field-preserved sample may vary depending on the dilution factors, percent moisture, and the range of the initial calibration curve. (See 5035A, sec. 8.2.2.)
High-level Collections (without chemical preservatives):
Any reported concentrations less than 200 ug/kg for samples collected without chemical preservation must be qualified as “may be biased low due to the sample not being collected according to 5035/5035A low-level specifications.” The 200 ug/kg concentration may not be reduced (even if supported by the low end of the initial calibration curve) as this concentration is the limit for high level sample collection – not the analytical procedure.
The collection of samples without the use of a chemical preservative is appropriate for those samples or wastes suspected of percent level contamination. (See 5035A, sec 8.2.3.)
Please contact me with any questions or any additional requests.
NOTE: The proper containers are Encore samplers or preserved VOA vials. Please call with any questions for the best option for your program.