13C3-Caffeine, 100 µg/ml, Methanol, 1ml Back Catalog number: 681491 Manufacturer: HPC STANDARDS GmbH Availability: In the manufacturer's stock Price on request - + Recommended 30050 EPA Method 548 Calibration Solution Price on request 684247 2-Nitropropane, 1000mg Price on request 679685 D6-Leucocrystal violet, 10mg Price on request