In a gas chromatography experiment, an internal standard was used. Which is considered the blank in this experiment:-

Question

In a gas chromatography experiment, an internal standard was used. Which is considered the blank in this experiment:-

1) Internal standard in diluent
or
2) Diluent only

or are 1) & 2) both acceptable?

Answer 1

In a gas chromatography experiment, an internal standard is used to provide a reference point for comparison and to account for any variability in the sample preparation and measurement process. The purpose of the internal standard is to help estimate the concentration of the compounds of interest accurately.

In this experiment, the internal standard is typically mixed with the analyte of interest, which is the substance being measured using gas chromatography. The analyte refers to the specific compound or compounds that are being analyzed.

So, to answer your question, the blank in this gas chromatography experiment is most commonly considered to be the diluent only, option 2. The diluent is a solvent or carrier gas used to dilute or suspend the analyte and internal standard before injection into the gas chromatography system. The diluent should be chemically inert and not contribute to the chromatographic separation or interfere with the measurement.

The diluent only blank serves as a control, representing the baseline or background signal obtained from the gas chromatography system without any analyte or internal standard present. It helps to account for any instrumental noise or impurities in the system.

While option 1 (internal standard in diluent) might also be considered a blank in some cases, it is not as common because the purpose of the internal standard is precisely to provide a known reference for comparison and calibration. Therefore, it is more appropriate to consider the diluent only blank as the baseline measurement in this context.

It is important to note that specific protocols and experimental designs may vary, so it is always best to refer to the specific guidelines provided by the method or experiment being conducted to determine the correct interpretation of a blank in gas chromatography experiments.