The Ricca Chemicals mixed calibration standard with a composition of 97.98% water, 1.94% nitric acid,<0.1 % arsenic, <0.1% silicon, <0.1% molybdenum, <0.1% hydrofluoric scid, is suitable for use in laboratory use only. it can be stored at a temperature of 15 to 30 degree c.<>0.1>