Scientific detection

Scientific expert:can be found working in a variety of difference organisation.

Ex

crime scene investigators retreive examine and intrepret evidence found at the crime scene. they work include:

taking figerprint, examining victim, suspect, trace forensic evidence.

environmental analysts :monitor industrial sites, investigate pollution incident and educate farmers

consumer public analysts: understand chemical analysis,law latest food technology

CHROMOTOGRAPHY :are use to find unknown susbtances

types of chromotography :

gas : greater in seperating power and seperate complex molecules.

thin layer :faster run, results easily produced

paper chromatography has six main stage:

1 if the substance is solid ,dissolve it in a liquid form of solution

2 place a spot of the solution on the pencil line on the sheet of the chromotography paper and allow it to dry

3 place the bottom edge of the paper into a suitable solvent

4 as the solvent rises up the paper,it dissolves the spot and carries it up the paper

5 the different chemicals in the solution separate,leaving marks on the paper.

COLOURMETRY use of colorimeter to find the intensity of the colour.

1 pass light through a test tube of a colourless solvent and set the colimeter to ZERO

2 pass light standart couloured solution of known concentration of a particular chemical.

3 plot the data to produce calibration graph

4 pass light to the unknown solution and compare its absorbance value with your plotted graph to find the concentration