CHEMetrics' alkalinity (total) test kits determine total or M alkalinity using a hydrochloric acid titrant and a bromocresol green/methyl red indicator. The end point of the titration occurs at pH 4.5. Results are expressed as ppm (mg/L) CaCO3. CHEMetrics hydrate alkalinity test kits use a hydrochloric acid titrant with a phenolphthalein indicator. The end point of the titration occurs at pH 8.3. Barium chloride is added to the sample to prevent interference from carbonate and bicarbonate alkalinity.