EPA 528 rev. 1.0 Internal Standard Solution 3 2 Analytes, each concentration as listed in dichloromethane; unit: 1x5mL 3841.8 1,2-Dimethyl-3-nitrobenzene [83-41-0] 100µg/mL 2081.6 2,3,4,5-Tetrachlorophenol [4901-51-3] 200µg/mL