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Why gunpowder contaminants give false result with DPA test reagent?
Wiki User
∙ 12y ago
There are several gunpowder contaminants such as the fertilizer, detergent, match head, even soil and cigarettes. They contain nitrates which gives similar result to gunpowder residues when treated with Diphenylamine (DPA) Reagent.However, their reaction differ from gunpowder nitrates from the characteristics of the specks as well as the distribution of the specks. Usually a gunpowder contaminants will show a smear of blue color .
Wiki User
∙ 12y ago
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What is the difference between reagent blank and sample blank?
Reagent Blank : Take reagent and add deionised water (in place of sample to be tested). Now measure the OD at specific wavelength --> this OD is your reagent blank. Substract this OD from your test result (with sample) to avoid any false +ve effect due to colour of reagents itself.Sample Blank : Take sample and measure the OD without adding reagents --> this OD is your sample blank. Substract this OD from your test result to avoid any false +ve effect due to colour and turbidity of sample itself. As it is the fact that colour and turbidity of each sample would vary from one to another.So now it is clear that Reagent blank is used to avoid bias due to colour of reagents and Sample blank is used to avoid bias due to sample itself.
Why does the oxidase reagent need to be fresh?
The oxidase reagent needs to be fresh because it contains the enzyme cytochrome c oxidase, which can degrade over time, leading to false-negative results if it is not active. Using fresh reagent ensures the accuracy of the test results.
If too much material is removed from a reagent container the excess can be safely returned to the container if it has not touched anything?
Returning excess material to the original container can introduce possible contamination and compromise the stock solution. It's best practice to avoid returning unused reagent to its original container to ensure accuracy and purity of the stock solution for future experiments.
Can folliculitis cause a false positive hsv2 result?
No, folliculitis will note cause a false positive HSV2 result.
Is too much material is removed from a reagent container the excess can be safely returned to the container if it has not touched anything?
False. It is impossible not to have touched anything.
If too much material is removed from a reagent container the excess can be safely returned to the container if it has touched anything?
False. It is impossible not to have touched anything.
If too much material is removed from a reagent container the excess can be safely returned to the container if it has not touched anything.?
False. It is impossible not to have touched anything.
When did the Chinese invent the gunpowder?
The Chinese invented gunpowder in 850 B.C.
When salt is dissolved in water the result is a heterogeneous mixture. Is this true or false?
False. It is homogeneous
Is it true or false the ability of a measurement to be reproduced with the same result is a sign of accuracy?
false
What does the or mean in java?
That's the boolean "or" operator. It calculates a result based on two boolean values. The result is false if both starting values are false; in all other cases, the result is true.
What does ! mean in java?
That's the boolean "or" operator. It calculates a result based on two boolean values. The result is false if both starting values are false; in all other cases, the result is true.
