Multi-Element Internal Standard Back Catalog number: 50160 Manufacturer: ABSOLUTE STANDARDS Availability: In the manufacturer's stock Price on request - + Recommended 2518.7-500MG Theophylline, neat, Solvent-neat, Unit 500mg, # of units-1, Cas.no. 58-55-9 Price on request 94535 USP 467 Price on request 0220.20-K-T Perylene, 1000µg/mL, Solvent-toluene, Unit 1mL, # of units-1, Cas.no. 198-55-0 Price on request