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