Multi-Element QC-21 Check Standard Solution is used as a certified reference material or quality control check standard for inductively coupled plasma optical emission spectroscopy (ICP-OES). It is also used in inductively coupled plasma mass spectrometry (ICP-MS), and flame or furnace atomic absorption spectroscopy.

Molecular Formula: Matrix: 5% HNO₃/tr. F-/tr. tartaric acid
Physical Form: Liquid
UN No.: UN3264
MDL No.: MFCD00803610