Figure 6. Calibration curve for D₃-BMAA.

Solutions of 10 to 1000 pg/μl H₃-BMAA and 250 pg/μl D₃-BMAA were combined with homogenates of mouse liver or cerebrum, or human cerebrum for comparison, derivatized with ethyl chloroformate, and analyzed by GC/MS. The ratio of the amount of H₃-BMAA to D₃-BMAA in each sample was plotted against the ratio of relative response for m/z 116 (H₃-BMAA) to m/z 119 (D₃-BMAA). Linear regression analysis with 95% confidence intervals are plotted along with the seven amount ratios for each tissue homogenate (r² = 1.00 and P < 0.0001 for each). Slope for mouse cerebrum and mouse liver were 1.15 ± 0.01 and 1.04 ± 0.01; human cerebrum yielded results virtually identical to mouse cerebrum.