Key Terms and Definitions in Chemical Analysis

Front

Random Errors (Indeterminate Errors)

Back

Errors caused by uncontrollable variables, leading to random fluctuations in measurement results around the mean. Affects precision but not accuracy.

Front

Systematic Errors (Determinate Errors)

Back

Errors that consistently affect all measurements in the same way, impacting accuracy. Causes include instrumental errors, method errors, and personal errors.

Front

Gross Errors

Back

Rare errors caused by mistakes like misreading scales or incorrectly recording results, leading to outliers.

Front

Outliers

Back

Data points that differ significantly from other measurements in a dataset, often due to gross errors.

Front

Bias

Back

A measure of systematic error in analysis. Positive bias results are higher than the true value, while negative bias results are lower.

Front

Standard Reference Materials (SRMs)

Back

Certified materials with known analyte concentrations, used to verify the accuracy of an analysis.

Front

Calibration

Back

The process of determining the relationship between instrument response and analyte concentration, detecting and correcting systematic errors.

Front

Blank Solution

Back

A solution containing all reagents and solvents used in analysis but no analyte, revealing contamination or interference.

Front

Precision

Back

The consistency of repeated measurements under the same conditions, measured by standard deviation and variance.

Front

Accuracy

Back

The closeness of a measurement to the true or accepted value, expressed by absolute error and relative error.