Performance Evaluation Studies
The Sawyer Environmental Chemistry
Research Laboratory participates in various performance evaluation
studies to enhance quality assurance of data produced. There are two
ongoing evaluations and several invitational inter-laboratory
comparisons. Detailed performance results can be furnished upon request.
1. National Water Research
Institute, Environment Canada (NWRI)
a. Participants are evaluated through
data comparisons with other laboratories throughout the United States
and Canada. SECRL participates in biannual proficiency testing studies
on natural waters through NWRI. The parameters assessed include almost
all of the inorganic water chemistry procedures that are available at
b. SECRL participates in the Ecosystem Performance Evaluation study for
trace elements in sediment. The sediment study is a semiannual
evaluation that began in 2001.
2. Norwegian Institute for Water
The International Cooperative Program on Assessment and Monitoring of
Acidification of Rivers and Lakes is a NIVA program in which SECRL
analytical results are evaluated against about 75 other laboratories.
The reported analytes are those related to acidification: pH,
alkalinity, anions, base cations and 7 trace metals. The NIVA
inter-comparison study is once per year.
3. National Institute for Standards
The Sawyer Environmental Chemistry Research Laboratory was invited to
participate in an inter-laboratory comparison exercise in 2001 and 2003
for trace elements in marine animal reference material. The results from
SECRL and 30 other laboratories are used to determine baseline trace
metals data for a new whale liver QA material.
4. NIMT/University of Edinburgh
SECRL took part in an inter-comparison study on the elemental content of
a candidate reference material for ombrotrophic peat. Several trace
metals were reported, including mercury.
5. Environmental Resource Associates
Proficiency testing samples are analyzed biannually to meet the State of
Maine certification requirement for mercury in wastewater using method