Table 2.
Comparison of blood-ethanol concentrations determined using 10 or 100 µL aliquots of venous whole blood.
| Sample | Mean BAC for 100 μL volume (mg/100 mL) | SD | CV% | Mean BAC for 10 μL volume (mg/100 mL) | SD | CV% | Difference (mg/100 mL) | Paired t-test p-value |
|---|---|---|---|---|---|---|---|---|
| 1 (M) | 65 | 1.45 | 2.23 | 64 | 2.29 | 3.56 | 0.73 | 0.649 |
| 2 (M) | 74 | 1.33 | 1.79 | 75 | 1.07 | 1.43 | 0.29 | 0.820 |
| 3 (M) | 56 | 0.99 | 1.77 | 56 | 2.20 | 3.90 | 0.69 | 0.645 |
| 4 (F) | 7a | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| 5 (M) | 57 | 0.37 | 0.65 | 58 | 0.72 | 1.24 | 0.96 | 0.194 |
| 6 (M) | 20 | 0.45 | 2.23 | 20 | 0.23 | 1.12 | 0.35 | 0.128 |
| 7 (M) | 67 | 0.78 | 1.17 | 71 | 0.32 | 0.45 | 3.52 | 0.005 |
| 8 (F) | 26 | 0.60 | 2.33 | 27 | 1.26 | 4.65 | 1.29 | 0.245 |
| 9 (F) | 26 | 0.54 | 2.07 | 27 | 0.45 | 1.67 | 0.93 | 0.009 |
| 10 (M) | 23 | 0.99 | 4.29 | 21 | 0.52 | 2.45 | 1.89 | 0.037 |
| 11 (M) | 19 | 1.28 | 6.63 | 19 | 0.92 | 4.86 | 0.42 | 0.254 |
| 12 (M) | 17 | 1.44 | 8.61 | 16 | 0.72 | 4.64 | 1.18 | 0.101 |
| 13 (M) | 28 | 0.51 | 1.83 | 28 | 0.79 | 2.87 | 0.09 | 0.742 |
| 14 (M) | 31 | 1.12 | 3.60 | 30 | 1.22 | 4.05 | 0.88 | 0.399 |
| 15 (M) | 19 | 2.17 | 11.48 | 19 | 0.55 | 2.91 | 0.01 | 0.606 |
| 16 (M) | 27 | 1.29 | 4.81 | 27 | 0.73 | 2.68 | 0.44 | 0.629 |
| 17 (M) | 25 | 0.81 | 3.24 | 26 | 1.07 | 4.17 | 0.52 | 0.335 |
| 18 (M) | 29 | 1.16 | 4.01 | 29 | 1.17 | 4.03 | 0.01 | 0.984 |
| 19 (M) | 25 | 0.97 | 3.81 | 23 | 0.97 | 4.25 | 2.49 | 0.038 |
| 20 (F) | 31 | 1.42 | 4.62 | 30 | 0.07 | 0.25 | 1.10 | 0.485 |
| 21 (M) | 25 | 1.55 | 6.19 | 27 | 1.04 | 3.87 | 1.75 | 0.299 |
| 22 (M) | 64 | 0.37 | 0.58 | 62 | 0.74 | 1.19 | 2.31 | 0.392 |
| 23 (M) | 58 | 1.11 | 1.90 | 52 | 1.11 | 2.13 | 6.08 | 0.007 |
| 24 (M) | 67 | 1.02 | 1.52 | 62 | 0.70 | 1.13 | 5.21 | 0.087 |
| 25 (M) | 59 | 1.22 | 2.07 | 58 | 1.01 | 1.74 | 0.61 | 0.435 |
| 26 (M) | 76 | 0.70 | 0.92 | 74 | 1.41 | 1.89 | 1.47 | 0.195 |
| 27 (M) | 72 | 0.84 | 1.17 | 73 | 1.88 | 2.60 | 0.41 | 0.531 |
| 28 (M) | 42 | 1.88 | 4.44 | 43 | 0.68 | 1.57 | 0.91 | 0.563 |
| 29 (M) | 64 | 2.33 | 3.66 | 62 | 1.13 | 1.81 | 1.51 | 0.496 |
| 30 (M) | 64 | 1.41 | 2.20 | 67 | 2.81 | 4.18 | 2.75 | 0.224 |
| 31 (M) | 63 | 2.26 | 3.57 | 65 | 1.16 | 1.80 | 1.35 | 0.365 |
| 32 (F) | 32 | 1.92 | 6.07 | 33 | 0.79 | 2.36 | 1.76 | 0.133 |
| 33 (M) | 21 | 1.01 | 4.74 | 20 | 0.59 | 2.88 | 1.09 | 0.322 |
| 34 (M) | 73 | 0.46 | 0.63 | 72 | 1.01 | 1.41 | 0.74 | 0.220 |
| 35 (M) | 31 | 0.27 | 0.84 | 30 | 0.09 | 0.30 | 1.56 | 0.011 |
| 36 (M) | 21 | 0.55 | 2.60 | 18 | 1.15 | 6.32 | 2.85 | 0.077 |
| 37 (F) | 35 | 0.22 | 0.63 | 35 | 0.34 | 0.97 | 0.56 | 0.350 |
| 38 (M) | 65 | 0.88 | 1.34 | 66 | 0.68 | 1.03 | 1.28 | 0.258 |
| 39 (M) | 63 | 1.22 | 1.93 | 62 | 1.14 | 1.83 | 0.73 | 0.659 |
| 40 (M) | 36 | 1.06 | 2.97 | 33 | 0.96 | 2.92 | 2.77 | 0.009 |
Our results indicate that a 10-fold dilution in sample volume does not result in significant difference in detected alcohol concentration of this sample matrix.
aValue was below the limit of quantitation of the method.
BAC: blood-alcohol concentration; SD: standard deviation; CV: coefficient of variance; M: male; F: female.