Module 1 Flashcards
Quantitative unit of measure
Physical quantity or dimension, such as mass, length, time, or volume
Specifications for AR chemicals established by
American Committee Society (ACS)
Methods of water purification
Prefiltration
Distillation
Deionization
Reverse osmosis
Ultrafiltration and nano filtration
Primary standard
Highly purified chemical that can be measured directly to produce a substance if exact known concentration and purity
(Certified by ACS)
Who lists and controls categories of water?
Clinical and Laboratory Standards Institute (CLSI)
Basic parameters
Microbiologic count, pH, resistivity, silicate, particulate matter, organics
Solute
A substance dissolved in a liquid
Analytes
Biologic solutes
Solvent
Liquid in which solute is dissolved
Solution
Solute plus solvent
Concentration can be expressed as
Percent solution, molarity, molality, normality, moles
Percent solution
Amount of solute per 100 total units of solution
(w/w, v/v, w/v)
Normality
Number of gram equivalent weights per 1 L of solution
Colligative properties
Osmotic pressure, vapor pressure, freezing point, boiling point
Redox potential
Measure of ability of solution to accept or donate electrons
Conductivity
Measure of how well electricity passes through a solution
pH
Inverse log of hydrogen ion concentration
Buffers
Weak acids or bases and their related salts that minimize changes in hydrogen ion concentration
Laboratory vessels
Flasks, beakers, graduated cylinders
Pipettes
Glass or plastic utensils used to transfer liquids
Burettes
Look like wide, long, graduated pipettes with stopcock at one end
Syringes
Sometimes used for transfer of small.voluked in blood has analysis or in separation techniques
Beakers
Straight-sided jar, wide mouth w/ pouring spout, volume in mL
Mixing liquids, holding liquids, estimating volume
Erlenmeyer flask
Flat bottom with sloping sides, narrow neck that can be stoppered, mL
Holding liquids, mixing solutions, measuring noncritical volumes
Volumetric flask
Bulbous bottom, narrow neck; single, calibrated volume marker
Measuring critical volumes, preparing solutions
Graduated cylinder
Upright, straight sided tube, flared base, volume gradations
Measure noncritical volumes
Test tubes
Straight sided tubes, glass or plastic, may have caps, may have conical bottom
Contain liquid samples, contain chemical reactions
Glassware made of
Pyrex or kimax heat-resistance glass
Desiccator
A closed, airtight chamber
Desiccant
Drying agent that removes moisture from air and other substances
Balances classified by
Design, number of pans (single or double), mechanical versus electronic
Balance operating range
Precision, analytic, microbalance
Centrifugation
Process in which centrifugal force is used to separate solid matter from a liquid suspension
Centrifuge parts
Head or rotor
Carriers or shields attached to vertical shaft of motor
Metal enclosure
Force depends on
Mass, speed, radius
Centrifuged classified according to:
Bench top versus floor
Refrigeration
Rotor head type (fixed, hematocrit, swinging bucket, angled)
Maximum speed attainable
Centrifuge applications
Separating serum or plasma from blood cells
Separating supernatant from a precipitate in analytic reaction
Separating two immiscible liquids or expelling air
RPM
Revolutions per minute
RCF
Relative centrifugal force
RCF calculation (G-force)
(1.12x10^-5)x radius x RPM^2
Centrifuge interferences
Time, temperature, braking
Parts of a pipette
Bore, bulb, delivery tip, stem, mouthpiece, delivery tube
Identifying information on a pipette
Total capacity
Increments
TD or TC
Tolerance (transfer pipettes only)
Double painted bands or frosted band
TD
To deliver or to dispense
TC
To contain
TC
To contain
Volumetric pipettes
Transfer (single)
Critical volume, non-viscous
No blow out
Non-viscous
Serum, urine, most chemical solutions
Viscous
Whole blood
Synovial
Ostwald-folin pipette
Transfer (single)
Critical volume, viscous, blow out
Mohr pipette
Measuring (multiple)
Noncritical
Not calibrated to tip, no blow out
Serological pipette
Measuring (multiple volumes)
Noncritical
Calibrated to tip, blow out remaining liquid
Blow out indicated by
Double painted rings or etched rings at the mouthpiece
Selecting a pipette
Type of liquid
Importance of measurement
Volume needed
Max pipette volume (no greater than 10x the volume)
Clean and no cracks
Why prewet?
Pipettes are calibrated to deliver the marked capacity after they have been wetted down
Micropipettes
Transfer volumes less than or equal to 1 mL
Semiautomatic with disposable tips
May have adjustable volume capability
Types of micropipettes
Air displacement
Positive displacement
Air displacement micropipettes
Plunger, tip eject button, volume, shaft, removable plastic tip
Holding pipette
Straight up and down
Filtration
Solution (filtrate) drains through filter into receiving vessel
Dialysis
Solution placed in bag or on one side of semipermeable membrane
Larger molecules remain in bag or on one side of membrane; smaller molecules and solvents are diffused out
Dialysis
Solution placed in bag or on one side of semipermeable membrane
Larger molecules remain in bag or on one side of membrane; smaller molecules and solvents are diffused out
Beer’s law
Concentration of Standard (Cs)/Absorbance of standard (As) = Concentration of unknown (Cu)/Absorbance of unknown (Au)
Dilution
A diluent to weaken original sample
Dilution formula
Volume of sample one/total volume = volume of sample 2/total volume
Temperature formula
F=1.8C+32
Titer
Smallest amount or concentration that will produce a reaction
Whole number
Working solution
Working solutions are made by diluting stock (concentrated) solutions
Kelvin calculation
C+273