CAS 7727-37-9 appears in our catalog under these names: ASTM D4629 Calibration Set, N @ 0-100 mg/L in Isooctane, Nitrogen Calibration Set: 0-100 mg/kg in Isoooctane, Nitrogen Check Standard: N @ 1 ppm in Isooctane, Nitrogen Check Standard: N @ 10 ppm in Isooctane, Nitrogen Check Standard: N @ 50 ppm in Isooctane. Offered by: VHG, Sigma-Aldrich. Available pack sizes: 7x2ml, 9x2ml, 5x2ml, set(2), set(7), 1L, 50L.