1Merck Ammonia Nitrogen Test Kit from GermanyReagent related issues

Is there a large deviation in the results after using the reagent? Most likely due to improper storage of the reagent, salicylic acid is prone to volatilization, and it is necessary to seal the bottle cap after each use to avoid spoilage and failure.

How long can the reagent be stored after opening? It is recommended to use it as soon as possible after opening. If it is not used up, it should be refrigerated according to the instructions to avoid strong light exposure.

What should I do if the reagent becomes turbid or discolored? This is a signal of reagent deterioration, and the original reagent within its validity period needs to be replaced and cannot be used anymore.

2、 Abnormal water sample detection issues

Does the water sample appear orange red and turbid after adding reagents? Mostly due to high ammonia nitrogen concentration, the water sample is diluted at a large multiple before testing.

Did white sediment appear after testing? Most likely, the water sample contains heavy metal ions, which can be detected by collecting the supernatant after coagulation and sedimentation pretreatment.

Does it not show color or does it show light color after adding the reagent? It may be that the water sample is acidic (neutralizing the alkaline solution in the reagent), or the reagent is expired or contaminated.

Is the result affected by residual chlorine interference? Add an appropriate amount of 3.5g/L sodium thiosulfate solution to every 0.5mL water sample, and confirm the removal of residual chlorine with starch potassium iodide test paper before testing.

3、 Operational and environmental issues

Are the test results generally low? It is necessary to check whether the water sample is acidic, or if the ammonia nitrogen evaporates due to untimely detection or improper storage after sampling.

Abnormal color development of blank sample? It may be that the experimental vessel or pure water is contaminated, and it is necessary to replace the pure water and clean the vessel.

Does the environmental temperature affect the detection? Yes, it needs to be operated at the appropriate temperature required by the test box. If the temperature is too high or too low, it will affect the reaction rate and color development effect.

4Merck Ammonia Nitrogen Test Kit from GermanyOther common questions

What form is the test result calculated in? Calculated based on the total nitrogen content of free ammonia and ammonium ions in water.

Is the cost of a single test high? Choosing Merck large packaging reagents can control the cost of a single test at around 10 yuan.

How to verify the accuracy of the test box? Verify with Merck original standard solution to ensure that the test results are within the allowable error range.