To verify the integrity of new cartridges, aqueous control solutions are available. The control solutions for levels 1, 2, and 3 are formulated at three clinically relevant levels with known concentrations of the following substances: – pH – pCO2 – pO2 – TCO2 – Sodium – Potassium – Chloride – Glucose – Lactate – Creatinine – BUN/Urea – Ionized Calcium (iCa)