Elemental compositions of deionized water and tap water

Quality of water used in experiments is critical for overall experiment success. Deionized water is the de facto water source for many experiments in science ranging from chemistry to biology. However, there are few reports of elemental composition of deionized water and tap water in the literature. In this short report, the elemental composition of deionized water and tap water from a laboratory was determined by inductively coupled plasma mass spectrometry (ICP-MS). Results indicated that concentrations of various elements in both deionized water and tap water were in the parts per billion (ppb) range, except for sodium, potassium, calcium and magnesium. Overall, quality of deionized water was good and suitable for use in experiments.