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The Correlation Coefficient: An Overview
Correlation and regression are different, but not mutually exclusive, techniques. Roughly, regression is used for prediction (which does not extrapolate beyond the data used in the analysis) whereasExpand
Analysis and Antioxidant Capacity of Anthocyanin Pigments. Part II: Chemical Structure, Color, and Intake of Anthocyanins
Anthocyanins belong to a large group of secondary plant metabolites collectively known as flavonoids, a subclass of the polyphenol family. They are a group of very efficient bioactive compounds thatExpand
Analysis and Antioxidant Capacity of Anthocyanin Pigments. Part I: General Considerations Concerning Polyphenols and Flavonoids
Many epidemiological studies have shown the benefits of a diet rich in fruit and vegetables to human health and for the prevention of various diseases associated with oxidative stress, such as cancerExpand
Intra-laboratory testing of method accuracy from recovery assays.
A revision on intra-laboratory testing of accuracy of analytical methods from recovery assays is given. Procedures based on spiked matrices and spiked samples are presented and discussed.
Intra-laboratory assessment of method accuracy (trueness and precision) by using validation standards.
Assessment of accuracy of analytical methods is a fundamental stage in method validation. The use of validation standards enables the assessment of both trueness and precision of analytical methodsExpand
An Overview of the Kjeldahl Method of Nitrogen Determination. Part I. Early History, Chemistry of the Procedure, and Titrimetric Finish
In 1883 Kjeldahl devised a method for the determination of nitrogen, which has become a classical measurement in analytical chemistry and has been used extensively over the past 130 years. In theExpand
An Overview of the Kjeldahl Method of Nitrogen Determination. Part II. Sample Preparation, Working Scale, Instrumental Finish, and Quality Control
The Kjeldahl method was introduced in 1883 and consists of three main steps: sample digestion, distillation, and ammonia determination (titration being the primary method). The Kjeldahl method usesExpand
Comprehensive Formulation of Titration Curves for Complex Acid-Base Systems and Its Analytical Implications
This article provides extensive and exhaustive mathematical description of titration curves related to acid-base systems with mixtures of mono- and polyprotic acids and their salts and basesExpand
Estimation of the uncertainty of indirect measurements from the propagation of distributions by using the Monte-Carlo method: An overview
The limitations of the Guide to the expression of Uncertainty Measurement (GUM) for evaluating the uncertainty of indirect measurements are presented. Expand
Characterization of anthocyanins from the fruits of baguaçu (Eugenia umbelliflora Berg).
Anthocyanin pigments in the berries of baguaçu (Eugenia umbelliflora Berg), a tropical fruit from Brazil, were extracted with 0.1% HCl in ethanol, and the crude anthocyanin extract was purified byExpand