Rapid Quality Control Test Kits

Instructions

1. Grind sample to a fine consistency with a coffee grinder or similar apparatus.

2. Place coffee filter into funnel.

3. Fill the snap-cap plastic vial to the one ounce mark with ground sample. Settle lightly but DO NOT PACK.

4. Add distilled water up to the three ounce mark, close the lid tightly and shake vigorously until all the sample is wet [approximately 15 seconds or less]. Immediately pour all of the sample mixture into the coffee filter and collect the filtrate in a clean sample vial. Do this step quickly to minimize the formation of a paste that will slow the filtration drastically.

5. Prepare a blank test for comparison by pouring eleven milliliters of distilled water into a clean vial. Keep this vial ready for the color reaction.

6. Prepare the sample by transferring one mL of filtrate (use a clean transfer pipet) and ten mL of distilled water (use graduated cylinder) into a clean vial: keep it stoppered until tested.

7. Add five (5) drops of REAGENT A into the blank test vial and into the sample vial: mix each gently. Then add three (3) drops of REAGENT B into the blank test vial followed by three (3) drops of REAGENT B into the sample vial. Start the timer immediately after the last drop of REAGENT B has been added to the sample. Gently mix the sample and the blank.

IMPORTANT: Timing is critical. Please run these tests one at a time and in the order described. There will be little or no reaction in the blank so that REAGENT B should be added to the blank vial before it is added to the sample vial. One blank will be okay for several samples if they are run one after the other. HOWEVER……active cereal dust from the air can affect the results and caps need to be kept on reagent bottles and on the vials to prevent spurious results. Also wash vials immediately after use and keep them clean for each determination.

8. The test time is 3.5 minutes. If a color difference occurs between the blank and the sample within the first minute, the peroxidase content is high [see reaction table below]. If a color difference occurs between 1 and 2.25 minutes, the peroxidase activity is moderate. If a color difference occurs between 2.25 and 3.5 minutes, the peroxidase activity is low. If no color difference occurs until after 3.5 minutes, the peroxidase activity is negative.

Reaction Time In Minutes Peroxidase Activity
Less than 1 min High
Between 1 and 2.25 min Moderate
Between 2.25 and 3.5 min Low
No reaction until after 3.5 min Negative

CLEANING INSTRUCTIONS

Snap-cap plastic vials, funnels, and glass vials should be washed thoroughly with warm soapy water between uses. Rinse with warm water followed by 3 rinses with distilled water. It is very important to use distilled water for all testing procedures and for final rinses. DO NOT SUBSTITUTE TAP WATER FOR DISTILLED WATER.

Your grinder should also be cleaned thoroughly between samples. A combination of vacuum dusting or brushing and damp towel wiping are good cleaning techniques to minimize errors. A small aliquot of the next sample that is ground and discarded prior to grinding the actual sample aliquot is also an excellent technique to dilute out any trapped or hidden dust from the grinder.

Remember that this is a sensitive method that requires attention to details, especially cleanliness.

Coffee filters are disposable and should not be reused. Coffee filters may be purchased locally if desired but always keep them clean to prevent cereal dust from contaminating them.

Store plasticware and glassware in a clean area free from cereal dust or other dirt. Reclosable plastic bags are very handy for maintaining equipment in a clean condition after washing and drying. Keep your daily supplies in the carrying case provided.

REAGENT A and B

Store these reagents in a refrigerator if possible to extend the life of the kit. The reagents are good for approximately 6 months to 1 year when kept cool. Pour out a small quantity of each reagent into their respective dropper bottles to use on a daily basis. Unused Reagent A or B should be refrigerated at the end of the day and warmed to room temperature before each use. Keep dropper bottles clean. Discard old reagents if they become contaminated or discolored.

LSB Products | 731 McCall Road | Manhattan, KS 66502 | T: 785.537.9773 | F: 785.537.1800 | lsbproducts@lsbproducts.com

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