and a coefficient of correlation, R2, of 1.00. An injection of 20 μL of 100 μg/L standard was used to confirm the calibration and was measured within 2% of the expected value. The limit of detection with this calibration was 0.33 μg/L for a 150 μL blood sample with 0.0495 ng mercury. Below 0.33 μg/L, measurements became im-precise due to background noise and residual mercury on the boats.
The calibration was confirmed daily at the start of each run using a 20 μL injection of standard solution containing 2 ng mercury. If the verification sample was off by more than 5%, a second 2 ng of mercury sample was run to establish a calibration factor to be applied to all of that day’s measurements. If the verification was off by more than 10%, a new calibration curve was estab-lished. The standard solution was used in conjunction with a 150 μL injection of SRM 966 level 1 to ensure