Data Analysis, Statistics, and Chemometrics

The Long, Complicated, Tedious, and Difficult Route to Principal Components: Part III

May 01, 2008

Howard Mark and Jerome Workman, Jr. continue their discussion of the derivation of the principal component algorithm using elementary algebra.

The Long, Complicated, Tedious, and Difficult Route to Principal Components: Part II

February 01, 2008

Howard Mark and Jerome Workman, Jr. continue their discussion of the derivation of the principal component algorithm using elementary algebra.

Archiving Electronic Records

December 01, 2007

Paper is easy to archive, but what about archiving electronic records? What do you do with all the electronic records that are generated? In this month's installment, columnist Bob McDowall explores the issue of electronic records management and looks at the recent guidance issued by the OECD for GLP laboratories.

Understanding the FDA's Current Thinking on Security and Access Control Requirements for Computerized Systems

November 01, 2007

Using information provided by guidance documents from outside the spectroscopy laboratory can be very useful when trying to meet the regulations that we must follow.

The Long, Complicated, Tedious, and Difficult Route to Principal Components: Part I

September 01, 2007

In this month's installment, columnists Howard Mark and Jerome Workman, Jr. present the derivation of the principal component algorithm using elementary algebra.

Addendum to Chemometrics in Spectroscopy

June 01, 2007

This column is the continuation of a series (1-5) dealing with the rigorous derivation of the expressions relating the effect of instrument (and other) noise to its effects on the spectra we observe. Our first column in this series was an overview. While subsequent columns dealt with other types of noise sources, the ones listed analyzed the effect of noise on spectra when the noise is constant detector noise (that is, noise that is independent of the strength of the optical signal). Inasmuch as we are dealing with a continuous series of columns, on this branch in the thread of the discussion, we again continue the equation numbering and use of symbols as though there were no break. The immediately previous column (5) was the first part of this set of updates of the original columns.

Limitations in Analytical Accuracy, Part II: Theories to Describe the Limits in Analytical Accuracy and Comparing Test Results for Analytical Uncertainty

February 01, 2007

In the second part of this series, columnists Jerome Workman, Jr. and Howard Mark continue their discussion of the limitations of analytical accuracy and uncertainty.

Interelement Corrections in Spectrochemistry

July 01, 2006

This tutorial reviews the mathematical models for dealing with interelement effects in optical emission and X-ray fluorescence spectrochemical analysis. Line overlaps and matrix effect corrections are examined.

Connecting Chemometrics to Statistics - Part II: The Statistics Side

June 01, 2006

In this month's installment of "Chemometrics in Spectroscopy," the authors again explore that vital link between statistics and chemometrics, this time with an emphasis on the statistics side.

Fully Integrated Analysis of Metabolites, Impurities, and Degradants Using LC–NMR–MS

May 01, 2006

Combining the three techniques of LC, MS, and NMR into one integrated system provides optimal use of NMR intrument time by using information-rich MS data to automatically guide the NMR operation. Here, the authors explore just this type of system.