PRELIM 01 - Instrumentation Flashcards
Measures the hydrogen ion concentration and the pH of an unknown solution
pH meter
Most modern pH meters also have a __________ which allows automatic temperature corrections since pH may vary relative to the temperature
Temperature probe
A pH meter is equipped with __________ and __________
Glass electrode, Reference electrode
An electrode that consists of a thin, pH sensitive glass membrane, the inside of which contains a solution with constant concentration of hydrogen ions
Glass electrode
Most common reference electrode
Calomel electrode
An electrode that incorporates a salt bridge filled with a saturated potassium chloride (KCl) solution
Calomel electrode
Is a method to measure how much chemical substance absorbs light by measuring the intensity of light as a beam of light passes through sample solutions
Spectrophotometry
Instrument used in spectrophotometry
Spectrophotometer
A spectrophotometer that makes the sample absorb light in the visible and near ultraviolet region of the electromagnetic spectrum
Ultraviolet-Visible (UV-VIS) spectrophotometer
Are assays used to measure the amount of light transmitted through a sample at a given wavelength
Colorimetric assays
UV/Vis spectrophotometer - Ultraviolet range
185-400 nm
UV/Vis spectrophotometer - Visible range
400-700 nm
IR spectrophotometer - Infrared range
700-15,000 nm
7 essential parts of UV/Vis spectrophotometer
White light source, Monochromator, Sample compartment, Detector, Read out device, Tungsten lamp, Deuterium lamp
Disperses light into its component’s wavelengths
Monochromator
Holds the transparent tube or cell containing the sample
Sample compartment
Measures the amount of light transmitted
Detector
Device that displays the reading
Read out device
Used as a light source in the visible region
Tungsten lamp
Used as a light source in the ultraviolet region
Deuterium lamp
The ratio of the intensity of the transmitted light to the incidence light
Transmittance
Refers to the amount of light absorbed by a sample
Absorbance
Law that is involved in the determination of the concentration of the absorbing species in the analyte solution
Beer-Lambert’s law
Law that states that the intensity of transmitted light decreases exponentially as any one of these factors increases
Beer’s law
Is a measure of how strongly a solution absorbs light in a particular wavelength
Molar extinction coefficient
Process used to separate or concentrate materials suspended in a liquid medium using the effect of gravity on the particles in suspension
Centrifugation
Fictitious force; peculiar to a particle moving on a circular path
Centrifugal force
Device used to separate the particles in a solution according to their size, shape, density, or the viscosity of the medium and the rotor speed
Centrifuge
Spectrophotometer that offers 5 nm spectral split and has a wavelength range of 200-1100 nm
GENESYS 5 spectrophotometer
Spectrophotometer used to measure UV/Vis absorbance from 200 to 1000 nm on 96 to/or 384-well microcplates
Multiskan go microplate spectrophotometer
Allows smaller sample volume (Microliter)
Microplate
The Beer-Lambert’s law is most accurate between the absorbance of __________ to __________
0.05 to 0.70
Using a multiskan go microplate spectrophotometer, one must incubate up to _____ and shake the microplate
45°C
A spreadsheet like __________ may be used to generate a standard calibration curve
Microsoft Office Excel
4 applications of UV/Vis spectrophotometer
Reaction kinetics, Quantitation, pKa determination, DNA structural information
4 things to avoid on or inside the cuvette because it diminishes the accuracy of the reading
Formation of bubbles, Turbidity, Fingerprints, Condensation
