1. Reagents
Detergent Concentration Indicator: Colorless liquid
Detergent Concentration Titrant: Colorless liquid
2. Directions for Use
2.1 Fill a clean bottle with 100ml of dishwasher tank water to the 100ml graduation line (see right image, left). Add 1 to 3 drops of the Detergent Concentration Indicator. If the tank water contains detergent, the sample will turn pink (see right image, right).
2.2 Hold the Titrant at a 45-degree angle and slowly add it drop by drop to the pink sample from step 2.1. Count the number of drops added. When the bottom of the sample begins to change color and appears colorless, you are approaching the titration endpoint (see image below, left). At this point, pause the titration and shake the sample until it returns to pink (see image below, second from left). Continue adding 1 drop at a time. When a drop creates a transparent cloud-like effect (see image below, third from left), stop immediately and shake. If the sample remains transparent after shaking, the titration endpoint is reached.
Count the total drops: 5 drops to reach colorless indicates a 0.1% detergent concentration in the tank. 10 drops indicate a 0.2% concentration, and so forth.
3. Detergent Concentration Testing
How do you determine if the dishwasher detergent purchased from a manufacturer meets the standard concentration? When different suppliers provide detergent in identical 20L (or 5Gal) containers, how can you tell if one supplier's concentration is only 50%? This kit allows for easy determination.
3.1 Take 0.2g of the detergent (concentrate) provided by the supplier and add it to a 100ml volumetric flask, then fill with RO water to the 100ml line. If a precision balance is unavailable, dilute 2.0g of the concentrate to 1000ml, then take 100ml for titration.
3.2 Add 1 to 3 drops of the Concentration Indicator; the sample will turn pink (see second image from left below).
3.3 Hold the Titrant at a 45-degree angle and add it drop by drop to the pink sample. If it takes 20 drops, the detergent is at standard concentration (100%). If it takes 14 drops, the concentration is 14/20 = 70%. If it takes 10 drops, the concentration is 10/20 = 50%, meaning it is only half the standard strength.
4. Active Ingredient Conversion (Powder & Solid)
4.1 Take 0.1g of the solid or powder detergent and add it to a 100ml volumetric flask, then fill with RO water to the 100ml line.
4.2 Add 1 to 3 drops of the Concentration Indicator; the sample will turn pink (see right image, right).
4.3 Hold the Titrant at a 45-degree angle and add it drop by drop to the pink sample. If it takes 25 drops, the concentration is 2.5 times the standard (25/10 = 250%). If it takes 20 drops, the concentration is 2 times the standard (20/10 = 200%).
4.4 Active Ingredient Conversion: If a solid/powder detergent container weighs 4kg and a liquid detergent container weighs 25kg, and the titration result for the solid detergent is 2.5 times, the conversion is: 25 / 4 / 2.5 = 2.5. This means one 25kg container of standard liquid detergent contains approximately 2.5 times the active ingredients of one 4kg solid container. Conversely, one 25kg liquid detergent container is roughly equivalent to 2.5 containers of 4kg solid detergent.