Instrument Focus

Aside from general chemometric training, we are often asked to detail the steps required to integrate into instruments or processes.  To that end, we can tailor training to tie to specific instrument or process systems.  Two of the most common fields are described briefly below.

Process Analysis

Infometrix software is often integrated as a stand-alone component in a process environment to calculate inferentials or to integrate an instrumental measurement into the flow for use in a digital control system.  Some examples:

  • When planning a sampling effort, chemometrics can be used to determine if the system is in steady state; and
  • When a system starts to migrate away from the control points, chemometrics can be used to find which measurements are responsible for the deviation.

Infometrix has had a long-standing relationship with Northwest Analytics of Portland, Oregon.  The chemometrics training can be combined with working through NWA’s Quality Analyst software, which can deploy Pirouette models in thin- and thick-client packages.  Contact us if you have interest in a combined training course.

Chromatography

Chromatography is an extremely versatile technique for the analytical laboratory. The chromatographic patterns generated by modern instruments are used in a wide variety of quantitative and qualitative analyses. The techniques are robust enough (and we have assembled experience enough) to allow a rapid development of chromatographic methods and move this experience into routine use in an analytical laboratory, quality control laboratory, or even an in-line process setting.

Although it is not always an expressed goal of a chromatographic analysis, we commonly use human pattern recognition skills to interpret the instrument output. The purpose of this pattern recognition step is usually to classify the sample in some way (e.g., is the sample of acceptable quality or is the sample consistent with a previous run?). Through the methods development process, we often strive to develop a set of rules-of-thumb for interpreting patterns. Often these heuristics involve calculating the ratio of two intensities or developing a simple decision tree based on a series of features in the chromatographic trace.

A chromatogram can be thought of as a chemical fingerprint where the pattern emerges from the relative intensities of the sequence of peaks passing by the detector. Chromatographic fingerprinting, whether by human intervention or automated in software, is used in two generic application areas:

  • To infer a property of interest (typically adherence to a performance standard)
  • To classify a sample into one of several categories (good versus bad, Type A versus Type B versus Type C, …)

We have worked through many applications in which pattern recognition software has simplified methods development and automated the routine use of robust pattern matching in chromatography.  With LineUp forcing more run-to-run consistency in the data and Pirouette models to automate the interpretation of the trace, routine chromatographic analysis just got a lot more sophisticated.