By Long on Monday, July 19, 2004 - 08:33 pm:

Hello, can anybody help to explain to me what's the purpose of internal standard? How does this internal standard method help in quantitative analysis? Do I need to add in an internal standard during the preparation of calibration curve? can the internal standard help to monitor the change in respond for the interested analyte (acephate)?

Do you know where to get the basic knowledge about the application of internal standard in quantitative analysis?

Thanks and thanks again....

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By chromatographer1 on Tuesday, July 20, 2004 - 08:53 am:

You wrote:

Hello, can anybody help to explain to me what's the purpose of internal standard?

The purpose is to remove variables in sampling and detector response in an analytical measurement.

How does this internal standard method help in quantitative analysis?

It allows greater accuracy in measurement and assures that the analyte in question is capable of being measured accurately (if the IStd is chosen well).

Do I need to add in an internal standard during the preparation of calibration curve?

Not all the time, but it is recommended if more accurate results are desired, and they usually are.

can the internal standard help to monitor the change in respond for the interested analyte (acephate)?

If the Istd is different than the analyte and its response is based on another factor than the analyte's, then yes, it might monitor the analyte's response or change in response.


Do you know where to get the basic knowledge about the application of internal standard in quantitative analysis?

Answer:
any good college course textbook in analytical chemistry