Internal Standard Stock Solution, 1.2ml, nonane Back Catalog number: EPA-1668IS Manufacturer: Wellington Laboratories Availability: 1 week Price on request - + Recommended 33005 EPA Method 502/524 Fortification Solution Price on request 1686.10-K-IO 2-n-Butyl-5-ethylthiophene, 1000µg/mL, Solvent-isooctane, Unit 1mL, # of units-1, Cas.no. 54411-06-2 Price on request 55021 WS Turbidity Price on request