Frequently Asked Questions: Reagents

  1. How often should volumetric solutions be re-standardized?
  2. How do I establish expiry dates for solutions, buffers, etc.?
  3. Where can I find the specification of reagents mentioned in USP–NF?
  4. Where can I find the brand name of the column used to validate a particular chromatographic procedure in USP–NF?
  5. Do I need to standardize Volumetric solutions bought ready to use?
  6. Can I use procedures other than the ones described in USP to standardize volumetric solutions?
  7. How many replicates should I do in the standardization of volumetric solutions?
  8. What is the quality grade of water to be used in the preparation of solutions, buffers, dissolution medium, etc.?

 


 

  1. How often should volumetric solutions be re-standardized?

    This decision is made based on the stability of the solution, its intended use and storage conditions. If this information is not stated in the text in a USP monograph for the particular volumetric solution, then it is up to your lab to define this frequency. You need to have experimental data to support your decision. Do not assume arbitrary frequencies.

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  2. How do I establish expiry dates for solutions, buffers, etc.?

    This decision is made based on the stability of the solution, its intended use and storage conditions. If this information is not stated in the text in a USP monograph for the particular solution, buffer, etc., then it is up to your lab to define this frequency. You need to have experimental data to support your decision. Do not assume arbitrary frequencies.

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  3. Where can I find the specification of reagents mentioned in USP–NF?

    The specification, quality grade and, in some cases, possible suppliers, of reagents used in any USP–NF monograph or general chapter can be found in the Reagent Specifications section of USP-NF.

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  4. Where can I find the brand name of the column used to validate a particular chromatographic procedure in USP–NF?

    The most updated information about chromatographic columns in USP can be found on the USP Chromatographic Columns Web site (sign-in required). In some cases you can also find information about alternative columns.

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  5. Do I need to standardize Volumetric solutions bought ready to use?

    Yes, volumetric solutions should be standardized before use and re-standardized periodically. The frequency of re-standardization should be defined based on the stability of the solution, its intended use, and frequency of use.

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  6. Can I use procedures other than the ones described in USP to standardize volumetric solutions?

    Yes, you can use any other standardization procedure as far as it gives at least the same degree of accuracy as the method described in USP.

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  7. How many replicates should I do in the standardization of volumetric solutions?

    The general recommendation is at least in triplicate.

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  8. What is the quality grade of water to be used in the preparation of solutions, buffers, dissolution medium, etc.?

    The water needs to be at least purified water.

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