Producers of mass spectrometers design their instruments to work well within specific parameters.

This month's column discusses the practicalities of detecting substitutions in counterfeit pharmaceuticals. The approaches used are practical "take home" lessons readers can apply to analyse unknowns in any mixture.

This month's instalment of "MS in Practice" provides a slightly different view of how practitioners employ the skills of interpretation that have been the focus in recent columns.

Electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) are now among the most commonly used techniques for creating ions, especially from small-molecule compounds in solution. They have become so familiar that now many articles only refer to them briefly. Yet each technique has dramatic predictive strength on the outcome and limits of an analysis.

Although interpreting MS spectra can be a thorny problem at least some of the time, in the words of Fred McLafferty, "All you are dealing with is the mass of the molecule and the masses of the pieces."

Liquid chromatography–mass spectrometry (LC–MS) has been increasingly indispensable in most analytical pursuits. Such acceptance would not have occurred without encouraging, early academic efforts and also the efforts of early practitioners who pressed manufacturers to improve and extend electrospray's capabilities. I briefly described the commercialization of LC in its halcyon period of the early 1990s in a 1998 article.¹

An increasingly available and attractive clinical analysis method, LC?MS nevertheless fails to directly benefit from the knowledge and experience of clinicians steeped in the immunoassay tradition.

The effects of increased data demand coupled with the torrential data outflow of our instruments can overwhelm even the most IT-savvy.

The Centers for Disease Control and Prevention (CDC) estimates that each year in the United States, 76 million people get sick, 325000 are hospitalized and 5000 die from food-related illnesses. Food-borne illness is a serious public health problem. —National Library for the Environment, Food Safety Issues in the 107th Congress, 2001, Donna U. Vogt.