Turbidity Standard (400 NTU) Back Catalog number: 54122 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 3355.11-100 2,4-DB methyl ester, 100µg/mL, Solvent-c.hexane or ac.nitrile, Unit 1mL, # of units-1, Cas.no. 18625-12-2 Price on request 50647 Sodium arsenate dibasic heptahydrate (As) Price on request 30104 EPA Method 551.1 Performance Check Soln Price on request