Midterm Flashcards
Conductance
Siemens ( S )
Activity( radionuclide )
Becquerel ( Bq )
Resistance
Ohms
Substance conc.
Mols per cubic meter
Volume
Cubic meter
Are obtain by combining 2 or more units by multiplication or division
SI derived units
States that the analyze is directly proportional to the amount of light it absorbs
Beer’s law
Is the term used to describe the monochromatic light this is absorbed by the sample and transmittance describes the light that passes through the sample
Absorbable ( OD )
Visual colorimetry which solely on the human eye
Dubosq colorimeter
A device for selecting a narrow band of wavelengths from a continuous spectrum
Monochromator
When the absorbance increases exponentially with an increase in the light path this law is followed
Lambert law
Incorporation of these two laws together with the contribution of blank
Bouguer
Formula of absorbance OD
A= 2 - log%T
Continuous spectrum examples
Filter ,Prism and Diffraction grating
Photoelectric colorimetry which employs a photoelectric device
Leitz photrometer
LambertlAw and contribution of bouguer
A= abc A= is for absorbance
a= absorptivity of the substance being measured
b= light in cm
c= conc. of the measured substance
Beer-Lambert law formula
Au x Cs /As = Cu
Two types of beer law
Duboscq colorimeter and Lietz photrometer
This formula applied to assay exhibit linear relationship between changes in absorbance with changes in conc to calculate the conc of unknown
Au x Cs /As = Cu
It minimizes stray light emitted by lamp and prevent scattered light from entering the monochromator
Entrance slit
Does not provide a continuous spectrum ,emitting radiation at a specific wavelength
Mercury vapor lamp
It controls the amount of emergent light that passes through the event
Exit slit
This provide the radiant energy
Light source
NIR
Near infrared
Are used for work in the UV region with 200-375 nm range
Hydrogen and Deuterium lamps
It sharply isolates specific wavelength of light which will made to pass the curvets
Monochromator
Responds to the radiant energy it absorbs by emitting electrons in a proportional amount to the initial light absorbed
Photomultiplier tube
Refers to the ability of the test to detect the smallest amount of the analyte In a solution or sample
Sensitivity
Is a soln of a particular analyte of known characteristics and known value
Standard
It holds the cuvet holding a soln containing the analytes to be measured
Cuvet holder
Is the measurement of the amount of light scattered by particles in suspension
Nephelometry
It converts light signal into an electral signal
Detector
Are design with 256-2048 photodiode that are arrange in linear fashion
Photodiode array detector
Cuvet holder for strongly acidic solution
Aluminosilicate glass cuvet
It provides the actual value or numerical data needed in the calculation of the value of analyte present in the sample
Read out device
Detector can be detected by
Galvanometer
Is the measurement of the amount of light blocked by particulate matter
Turbidimetry
A iron plate and a layer of selenium are partial description f the composition
Photocell or barrier layer cell
Cuvet should be used for assays using wavelength range UV region 200-380
Plastic or quartz cuvet
Occurs when a molecule absorbs light of a particular short wavelength and is thereby stimulated to emit light of longer wavelength
Fluorescence
As light from a radiant energy source passes through an interference filter it is projected to the slide at a 45 degree angle
Reflectance spectrophotometry
