EPA Method 528 Internal Standard Back Catalog number: 93188 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 679809 Sulfadimethoxine, 100 µg/ml, Methanol, 1ml Price on request 79183 Benzyl butyl phthalate Price on request 98402 IP 391-95 Calibration Level 2 Price on request