Lynn Vanatta

Statistics in Analytical Chemistry: Part 52—Corrections and Clarifications
Tuesday, April 09, 2013
As was stated at the end of Part 50, this current installment will be the last in the “Statistics in Analytical Chemistry” series. The mission of this article is to correct mistakes and clarify ... read more
Statistics in Analytical Chemistry: Part 51–Internal Standards With Electrospray Mass Spectrometry
Thursday, February 14, 2013
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
Statistics in Analytical Chemistry: Part 50—Sampling Theory
Friday, November 23, 2012
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
Statistics in Analytical Chemistry: Part 49—Relative Standard Deviations and Detection
Monday, August 27, 2012
It is possible to associate a relative standard deviation or the more general relative measurement uncertainty (RSD and RMU, respectively) with a detection limit (DL). read more
Statistics in Analytical Chemistry: Part 48—Relative Standard Deviations (RSDs)
Tuesday, June 05, 2012
The previous installment dealt with several regression practices that are risky in the world of calibration and recovery. read more
Statistics in Analytical Chemistry: Part 47—Risky Calibration Practices
Monday, April 09, 2012
In analytical chemistry, simple linear regression is often used to perform calibration or recovery activities. read more
Chromatography and Linear Regression: An Inseparable Pair
Tuesday, March 06, 2012
Chromatographs are everywhere; many analytical labs may now contain more such instruments than analytical balances. Indeed, gas chromatographs and liquid chromatographs are used to solve separation ... read more
Statistics in Analytical Chemistry: Part 46—R² (Concluded)
Wednesday, February 08, 2012
Over the course of the past two articles (Part 44,Oct 2011, and Part 45, Nov/Dec 2011), R2 has been defined, its components have been explained verbally and mathematically, and the statistic’s ... read more
Statistics in Analytical Chemistry: Part 45—R² (Continued)
Tuesday, November 01, 2011
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
Statistics in Analytical Chemistry: Part 44—R²
Saturday, October 01, 2011
Imagine that a new method has been developed and now needs a calibration curve. read more
Statistics in Analytical Chemistry: Part 43—Pass-Fail Methods (Concluded)
Monday, June 13, 2011
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
Statistics in Analytical Chemistry: Part 42—Pass-Fail Methods
Wednesday, April 06, 2011
In the past articles, the discussions about methods have always dealt with procedures that estimate sample concentrations over a range of levels. read more
Statistics in Analytical Chemistry: Part 41—Blanks (Concluded)
Friday, January 28, 2011
The previous article (American Laboratory, Oct 2010) left off with two interesting questions: 1) How does an analyst decide whether a positive response for a blank is low enough to be ignored? and 2) ... read more
Statistics in Analytical Chemistry: Part 40—Blanks
Friday, October 29, 2010
There are indeed statistical issues related to blanks. To set the stage, a discussion of the concept itself will be helpful. read more
Statistics in Analytical Chemistry: Part 39—Inexact Replicates: Example
Thursday, August 12, 2010
The previous installment (Part 38, American Laboratory, May 2010) outlined the regression-diagnostic steps needed when replicates are not exact. read more