Technical Articles

In modern scientific laboratories, the electrospray mass spectrometer is being used extensively. The instrument is highly specific and for many applications is quite sensitive. read more

In the previous installment (American Laboratory, Oct 2011), the terms that contribute to R2 were defined and a formula relating them was developed. read more

Throughout this series of articles, the emphasis has been on calibration and recovery curves, which are necessary for the quantitative analysis of samples via analytical methods that involved simple ... read more

In analytical chemistry, simple linear regression is often used to perform calibration or recovery activities. read more

The previous article (American Laboratory, Apr 2011) ended with an unsolved problem: how to implement a pass-fail method if the blank matrix contains a non-negligible amount of the analyte. read more

Measurement is at the heart of what analytical chemists do on a routine basis. read more

In the past articles, the discussions about methods have always dealt with procedures that estimate sample concentrations over a range of levels. read more

Consider the following algebraic equation: 5x + 11y + 39z = 106 Since this single expression has three unknowns, there are many possible solutions; a single exact solution cannot be found. read more

Since the beginning of this series of articles, the central topic has been calibration and its associated uncertainty. read more

Because of popular demand from readers, this installment will discuss the principles and calculations that underlie the lack-of-fit (LOF) test. read more