Anions, Environmental Reference Materials, Inorganics, Water Chemistry CRMs Cyanide (free) #IS-029 $33.00 – $51.00 1000mg/L in Dilute NaOH. Derived from high purity Potassium cyanide, NIST traceable. read more Options Choose an option125 mL500 mLClear Add to cart Compare Catalog Number: IS-029. Options 125 mL, 500 mL Related products Quick View Add to cart Compare $59.00 Environmental Reference Materials Calcium – 125mL #IC-008 Quick View Add to cart Compare $59.00 Environmental Reference Materials Cyanide – 125mL #IC-019 Quick View Add to cart Compare $59.00 Environmental Reference Materials Chlorite – 125mL #IC-016 Quick View Add to cart Compare $59.00 Environmental Reference Materials Nitrite – 125mL #IC-031