Contamination

The Blank analysis option of the QC module provides the chemist with the ability to calculate contamination, based on the Blank samples, included within normal analytical work. It can be used to review the data on Blank samples stored in the Quality Control History file. The presentation of results can be both in statistical summary format or plotted in graphical format.

Control Charts For Analytical Contamination

The Blank analysis option within the QC module can produce three types of control charts for analytical contamination on blanks.

X-Chart - Blanks

This performance chart is a graph of the value of a blank sample within the given control limits, plotted against the number of observations.

Histogram Chart - Blanks

This is a relative frequency histogram. Each vertical bar represents the relative frequency of a sub-interval (referred to as classes in statistics) of concentration range. Relative frequency is the number of samples falling within a particular sub-interval, expressed as a percent.

The user of this chart can highlight whether this population is normally distributed.

Cusum Chart - Blanks

The chart quickly identifies any consistent bias between expected and actual results. The error between the expected and the actual result are accumulated and displayed as an ongoing chart. Any consistent biases are reflected in an upward or downward movement in the chart.

The same charts are available for analysis of standard samples and will display similar information with regard to analytical accuracy.