AUTOMATION

AUTOMATION

OF ANALYSIS

OF ANALYSIS

Some Advantages of automation:

Some applications:

- quality control

- process control

- environmental monitoring

Autotitrator

Titrations were of the first automated analytical techniques

Schematic representation of an automated colorimetric analysis

Autosamplers

Samplers:

Peristaltic pumps Syringe pump

Pumps:

Operates by means of rotating bars attached to a chain drive which compresses the plastic tubes to drive the liquid forward.

Automated determination of magnesium in urine using DAB (o,o’-dihydroxyazobenzene)

FLOW INJECTION ANALYSIS (FIA)

Involves injecting a liquid sample into a carrier stream which contains all chemicals necessary of the analysis.

The stream then flows through the detector.

The stream is unsegmented by air bubbles, thus dispersion of the sample occurs by both:

CONVECTIVE TRANSPORT DIFFUSIONAL TRANSPORT

Due to solution flow

Parabolic velocity profile in direction of flow

Due to concentration gradient

Radial diffusion

Block diagram of a flow injection spectrophotometric monitor for the determination of nitrate in river water

Selection valve

Injection valves

Valves: Load sample loop:

Flow through:

Results for continuous flow analysis of ethanol in beverages

CONSTANT MONITORING

Generally difficult to analyse within a process stream.

Often divert some of the steam and introduce a sampling loop.

The analysis could act as a feedback for optimising control of the process.

Submersible UV-Vis spectrometer

Schematic diagram of an analyser/controller for an acid catalysed reaction

ROBOTICS

Used when large numbers of samples have to be routinely processed before measurement.

In this country robotics is currently mainly used in the fire assay for gold and PGM’s

Manual Robotic

The pouring process:

Robotic lab