13-11-2012, 03:16 PM
Automated Methods of Analysis
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Introduction...
By IUPAC terminology, automatic devices do not modify their operation as a result of feedback from an analytical transducer. For example, an automatic acid/base titrator adds reagent to a solution and simultaneously records pH as a function of volume of reagent
Advantages and Disadvantages of Automatic Analyses
Automated instruments offer a major economic advantage because of their savings in labor costs.
Their speed, which is frequently significantly greater than that of manual devices.
A well-designed analyzer can usually produce more reproducible results over a long period of time than can an operator employing a manual instrument.
Unit Operations in Chemical Analysis
All analytical methods can be broken down into a series of eight steps, or unit operations, any one of which can be automated. The next table lists the steps in the order in which they occur in a typical analysis.
FLOW-INJECTION ANALYSIS...
Flow-injection methods, in their present form, were first described in the mid 70s. Flow-injection methods are and outgrowth of segmented-flow procedures, which were widely used in clinical laboratories in the 1960s and 1970s for automatic routine determination of a variety of species in blood and urine samples for medical diagnostic purposes.
Sample Injectors and Detectors
The injectors and detectors employed in flow-injection analysis are similar in kind and performance requirements to those used in HPLC. For successful analysis, it is vital that the sample solution be infected rapidly as a pulse or plug of liquid
[attachment=39252]
Introduction...
By IUPAC terminology, automatic devices do not modify their operation as a result of feedback from an analytical transducer. For example, an automatic acid/base titrator adds reagent to a solution and simultaneously records pH as a function of volume of reagent
Advantages and Disadvantages of Automatic Analyses
Automated instruments offer a major economic advantage because of their savings in labor costs.
Their speed, which is frequently significantly greater than that of manual devices.
A well-designed analyzer can usually produce more reproducible results over a long period of time than can an operator employing a manual instrument.
Unit Operations in Chemical Analysis
All analytical methods can be broken down into a series of eight steps, or unit operations, any one of which can be automated. The next table lists the steps in the order in which they occur in a typical analysis.
FLOW-INJECTION ANALYSIS...
Flow-injection methods, in their present form, were first described in the mid 70s. Flow-injection methods are and outgrowth of segmented-flow procedures, which were widely used in clinical laboratories in the 1960s and 1970s for automatic routine determination of a variety of species in blood and urine samples for medical diagnostic purposes.
Sample Injectors and Detectors
The injectors and detectors employed in flow-injection analysis are similar in kind and performance requirements to those used in HPLC. For successful analysis, it is vital that the sample solution be infected rapidly as a pulse or plug of liquid