Calcium Hardness Back Catalog number: 54143 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 674523 PSA-GCB-Mix for 2007.01 per AOAC Price on request 11712.12-100-IO 2,2',3,4,6-Pentachlorobiphenyl ,100 µg/mL,isooctane,1mL, Price on request DF-1348-S 1,3,4,8-Tetrachlorodibenzofuran, 1.2ml x 50ug/ml, nonane Price on request