Calcium Hardness Back Catalog number: 54543 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 0013.16-100-T 1,3-Dinitropyrene, 100µg/mL, Solvent-toluene, Unit 1mL, # of units-1, Cas.no. 75321-20-9 Price on request 0295.19-200-T 4-Methylchrysene, 200µg/mL, Solvent-toluene, Unit 1mL, # of units-1, Cas.no. 3351-30-2 Price on request LA13585200AL Fenthion-oxon-sulfone, 10µg/mL in Acetonitrile, 1ml Price on request