Detector Signal (in mV) spiked ASA Method 1 (35C) concentration (in mg/L) 0.25 0.5 20 33 71 125 18 31 75 119 21 32 45 73 131 Method 2 (45C) 25 41 91 136 181 23 38 87 145 172 28 39 95 139 175