What is the purpose of the "blank" in a experimental analysis?
In experimental analysis, the purpose of a "blank" is to provide a baseline or reference measurement for comparison. It is an important control that helps to account for any background noise, contamination, or interferences that may be present in the measurement system.
A blank is essentially an analysis performed without the sample or analyte of interest. It is often a measurement of the solvent, reagents, or matrix used in the experiment. By measuring the blank, any inherent noise or contamination introduced by these components can be identified and subtracted from the measured values of the samples.
To perform a blank measurement, you typically follow these steps:
1. Prepare a sample that contains all the components of your experiment except the analyte. This can be achieved by combining the solvent or matrix with reagents, buffers, or any other necessary components.
2. Run the measurement instrument or procedure with this blank sample. Ensure that the same conditions, settings, and parameters are used as in the subsequent sample measurements.
3. Record the measurement values obtained from the blank. These values represent the baseline or background signal.
4. Subtract the blank values from the subsequent sample measurements to account for any noise or contamination introduced by the experimental system.
This subtraction allows you to isolate the specific effects caused by the analyte and obtain more accurate and reliable measurements. The blank also helps in calibrating the instrument and establishing appropriate thresholds for detection and quantification.