title: Sandwich standardization in flow-injection analysis.
abstract: The use of internal coupling of valves as an easy and handy way to intersperse calibration and determination is shown. The advantages of derivative over normal recordings are considered.
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Córdoba, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rios
authors.forename: M D
authors.initials: MD
authors.lastname: de Castro
authors.forename: M
authors.initials: M
authors.lastname: Valcarcel