Table B6. Data
quality objectives for organic analyses |
| Parameters/QC
Measurements |
Frequency |
Control
Limit Criteria |
| Laboratory method
blank |
1 per 20 samples |
Warning limit -- analyst should
use best judgement if analytes are detected 3 times the method detection
limit
Action limit -- no analyte
should be detected at >3 times the method detection limit |
| Instrumental detection
limit |
1 per project |
<5% relative
standard deviation for seven replicate measurements |
| Method detection
limit |
1 per project |
Analyst should
use best judgement if the calculated method detection limits are higher
than the target method detection limit of 2.0 ppb wet weight for PCBs and
pesticides, 10.0 ppb wet weight for PAHs, and within a range of 1-10 pptr
for each PCDD and PCDF congener as specified in Table B5 |
| Surrogate internal
standards |
Each sample |
40-150% recovery
Recommended control limit
for percent difference between accuracy-based material surrogate recoveries
and sample surrogate recoveries is <50% |
| Matrix spike |
1 per 20 samples |
Recovery should
be within 50-120% for at least 80% of the analytes |
| Laboratory triplicates |
1 per 20 samples |
<25% relative standard
deviation for analytes >10 times the method detection limit |
| ccuracy-based
material |
1 per 20 samples |
Recommended control
limit for percent difference of certified or consensus value on average
for analytes >10 times the method detection limit is <30% |