Chapter 4 - Principles Of Instrumentation Flashcards
What are the principles of instrumentation?
- Spectrophotometry
- Reflectometry
- Flourometry
- Nephelometry
- Turbidimetry
- Refractometry
- Osmometry
- Flow Cytometry
- Electrochemistry
- Conductance
- Impedance
- Electrophoresis and Densitometry
- Isoelectric Focusing
- Chromatography
- Mass Spectrometry
Fundamental principles of absorption spectrometry.
It was developed by?
Spectrophotometery: Beer’s Law
By Beer and Lambert
What are the concentration of substances being measured for spectrophotometry?
Absorbance and Transmittance
The amount of light absorbed
Absorbance
The logarithm of transmitted light
Transmittance
Components of Spectrophotometer
- Light source
- Entrance Slit
- Monochromator
- Exit slit
- Cuvet
- Photodetector
- Read out device
provides the energy that the sample will modify.
It is also known as?
Light Source or Exciter Lamp
Emits radiation that changes in intensity very slowly as a function of wavelength
Continuum
Emit a limited number of discrete lines or bands of radiation
Line
Types of light source
Continuum and Line
Element that is the visible region of EMS
Tungsten
Element that provides UV radiation
Deutrium
Element that covers both UV and VR
Xenon
Kind of lamp that provides sharp lines in the UV and VR.
Used in several spectrophotometers
Mercury and Sodium Vapor Lamps
Component of spectrophotometer that excludes unwanted stray light.
Entrance Slit
Any light that impinges upon the detector that does not originate from a polychromatic light source.
Stray Light
Component of spectrophotometer that is used to select the appropriate wavelength
Monochromator
Types of monochromator
- Filters
- Prism
- Grating monochromators
- Holographic gratings
Types of filters
Pre sample filter and
post sample filters
Type of filter that limits the wavelengths of light that enter the sample
Pre-sample Filters
Type of filter that allows multi-wavelength light to pass through the sample
Post-sample Filter
Types of pre-sample filters
Absorption and Interference Filters
Type of pre sample filter that allows only limited domain of this spectrum to pass through the sample
Absorption Filters
Type of pre sample filter that enters magnesium fluoride chamber
Interference Filter
Component of Spectrophotometer that controls width of light beam
Exit Slit
Total range of wavelengths transmitted
Bandpass
Component of Spectrophotometer that is made of material that is transparent to radiation in the spectral region of interest.
It is also known as?
Cuvet or Sample Container
Component of Spectrophotometer that converts transmitted radiant energy into an equivalent amount of electrical energy
Photodetector
Types of Photodetector
- Photomultiplier Tubes (PMTs)
- Photovoltaic
- Vacuum Phototubes
- Silicon Diode Transducers
- Multichannel Photon Transducers
Most common type of Photodetector.
Highly sensitive to UV and VR
Photomultiplier Tubes (PMTs)
Type of photodetector that is used for measuring radiation in visible region.
Photovoltaic
Type of photodetector that has a semicylindrical cathode and wire anode sealed
Vacuum Phototubes
Type of photodetector that contains positive and negative charged semi-conductive materials.
Silicon Diode Transducers
Type of photodetector that consist of an array of small photoelectricsensitive elements
Multichannel Photon Transducers
Component of Spectrophotometer that indicates the amount of light passing through a sample.
It is also known as?
Read out device or Signal Processors
What are the parameters of Quality Control?
- Wavelength
- Absorbance
- Linearity
- Stray Light
A parameter of QC that Monitored by using special glass type optical filters.
Wavelength
A parameter of QC that use glass filters or solutions that have known substance or absorbance
Absorbance
A parameter of QC that yield a linear relationship between radiant power and concentration.
Linearity
A parameter of QC that is evaluated by using special cutoff filters
Stray Light
Types of Photometric Instruments
- Spectroscope
- Calorimeter
- Spectrometer
Type of photometric instrument that is used for visual identification of atomic emission lines
Spectroscope
Type of photometric instrument that uses human eye as detector and compares the observed color of the unknown sample against a standard or a series of colored standards of known concentrations.
Calorimeter
Type of photometric instrument that provides information about the intensity of radiation as a function of wavelength or frequency
Spectrometer
Types of spectrometer
- Single-beam
- Double-beam
Type of spectrometer that uses one measurement at a time at one specified wavelength
Single-beam Spectrophotometer
A type of spectrometer that slipts of chops the monochromatic beam of radiation into two components
Double-beam Spectrophotometer
components of double-beam spectrophotometer
- Space Design
- Time instrument
Component of double-beam spectrophotometer that uses two photodetectors: one for the sample beam and one for reference beam
Space Design
A principle of instumentation where the amount of a substance present can be measured as an indirect function of the reflected light.
Reflectometry
Types of Relfectance
- Specular
- Diffuse
Type of reflectance that occurs on a polished surface
Specular
Type of Reflectance that occurs on non polished surface
Diffuse
Components of Reflectometer
- Light Source
- Monochromatic Filter
- Slit
- Lens
- Photodetector
- Read Out Device
A principle of intrumentation that is based on an energy exchange process that occurs when certain compounds absorb electromagnetic radiation, BECOME EXCITED, and return to an energy level lower than or equal to their original level.
Also known as?
Flourometry or Molecular Luminescene
Components of Flourometer
- Light Source
- Primary Filter
- Cuvet
- Secondary Filter
- Photodetector
- Read Out Device
Types of Light Scatter in Nephelometry
Symmetrical and Forward
A type of light scatter that the wavelength is larger than diameter of particle
Forward
A type of light scatter that the wavelength is smaller than diameter of particle
Symmetrical
A principle of intsrumentation that detects light that is scattered at various angles; scattered light yields a small signal that must be amplified.
Nephelometry
TRUE OF FALSE
If wavelength is the same as the diameter of the particle, more forward scatter than other directions
TRUE
Components of Nephelometer
Light source Collimator Monochromator Cuvet Stray light strap Photodetector
A principle of instrumentation that is the measurement of the reduction in light transmission caused by particle formation
Turbidimetry
A principle of instrumentation that is based on light refraction.
Refractometry
TRUE OF FALSE.
Refractometry is the direct measurement of total solute concentration.
FALSE. Indirect.
Refractometry is dependent on:
- wavelength if light
- temperature
- nature of liquid or medium
- concentration of solute dissolved
A principle of instrumentation that is based on measuring changes in the coligative properties of solutions that occur owing to variations in particle concentration
Osmometry
What happens of osmolarity increases?
We are freezing point and
vapor pressure.
Osmotic Pressure INCREASES
Boiling Point is ELEVATED
Freezing Point is DEPRESSED
Vapor Pressure is DEPRESSED
A principle of instrumentation that whenever each particle passes single file through a laser light source, it produces a characteristic light pattern that is measured b y multiple detectors for scattered light and fluorescent light.
Flow Cytometry
Any object flowing through the instrument
Particle
Anything that is interpreted by the instrument to be a single particle
Event
A principle of instrumentation that involves measurement of the current or voltage generated
Electrochemistry
Electrochemistry includes:
- Potentiometry
- Coulometry
- Voltametry
- Amperometry
Measurement of potential (voltage)
Potentiometry
Measures the quantity of electricity (in coulombs)
Coulometry
Potential is applied to an electrochemical cell and current is measured
Voltametry
Measurement of the current flow produced by an oxidation-reduction reaction
Amperometry
A principle of instrumentation that includes the application of:
- monitoring water purity
- blood analyte measurement
- component detectors in HPLC, GC, Cell counters and capillary electrophoresis.
Conductance
A principle of instrumentation that is based on the change in electrical resistance across an aperture.
Who developed this?
Impedance by Wallace Coulter
A principle of instrumentation where the separation of charged compounds is based on their electrical charge
Electrophoresis and Densitometry
Cations
Cathode
Anions
Anode
A principle of instrumentation where separating molecules migrate through a pH gradient
Isoelectric focusing
Isoelectric Focusing is useful is measuring:
- serum ACP isoenzymes
- CK isoenzymes
- ALP
- Oligoclonal bands in CSF
A principle of instrumentation where the separation method is based on different interactions of the specimen compounds with the mobile phase and with the stat ionary phase as the compounds travel through a support medium
Chromatography
A principle of instrumentation that is based in fragmentation and ionization of molecules using a suitable source of energy
Mass Spectrometry
TRUE OF FALSE.
In general analytic methods, chemicals must meet the specifications of ACS
TRUE
Proper chemical selection and reagent preparation guideline is provided by:
CAP
Classifications of chemicals
- Analytic grade
- Spectograde, nanograde and HPLC grade
- Pharmaceutical chemicals
Pharmaceutical chemicals undergoes the specifications under:
United States of Pharmacopeia (USP), National Formulary (NF) and The Food Chemical Index
A classification of chemical that is routinely used
Analytic Grade
A classification of chemicals that is ultra-pure and has high standards of purity
Spectograde, nanograde and HPLC grade
IUPAC
International Union for Pure and Applied Chemistry
What is the purest type of water
Type I
IUPAC grades and name
Grade A - Atomic weight standard Grade B - Ultimate standard Grade C - Primary standard Grade D - Working standard Grade E -Secondary substance
Purification methods of water
Distillation
Reverse osmosis
Deionization
liquid is vaporized and condensed
Distillation
water is forced through a semipermeable membrane that acts as a molecular filter
Reverse Osmosis
passing water through insoluble resin polymers that contain anion- or cation-exchange resins
Deionization
Types of balances
- Unequal - Arm Substitution Balances
- Magnetic Force Restoration Balance
- TUP - Loading Balance
- Electronic Balances
Types of Laboratory Glassware
Thermal resistant glass Alumina silicate glass Acid and alkali resistant glass Low actinic glassware Flint glass
Examples of laboratory plasticware
Polypropylene Polyethylene Teflon Polycarbonate Polystyrene
Categories of pipets
Transfer and Measuring
Subclassifications of pipets
To contain
To deliver
To blow-out
Types of liquid in glass thermometers
Total and partial immersion
What includes the general analytic methods?
- Chemicals
- Water
- Balances
- Laboratory Glassware
- Laboratory Plasticware
- Pipets
- Thermometers
Component of double-beam spectrophotometer that uses one photodetector and alternately passes the monochromatic radiation
Time Instrument