1. Intro to Chemistry Flashcards
Identify methods used to purify water and which substances they target to reduce. (6)
- prefiltration —initially traps particulates
- distillation —liquid boiled, vaporized, and condensed for purification
- reverse osmosis —water forced through semipermeable membrane; removes particulates, organics, bacteria, ionized and dissolved materials; does not remove gases
- deionization — water passes through insoluble resin polymers; removes some or all ions; does not remove organics
- carbon filters —activated charcoal removes organics
- particulate filters —bacteria
List items that should be monitored during the water-purification process.
at minimum —resistivity and bacteria
List the criteria for Clinical Laboratory Reagent Water (CLRW). (5)
- resistivity > 10 MΩ x cm at 25°
- CFU < 10/mL
- total organic carbon < 500 ppb
- Silicates < 0.05 mg/L
- water passed through 0.22 𝜇m filter for particulates
Distinguish the differences between Type A and Type B glassware.
A —more accurate; must be of certified accuracy
B —twice the durability, not as accurate; used in student labs
Assessing, setting, or correcting a device usually by comparing or adjusting it to match or conform to a reliable, known, and unvarying measure
calibration
performed after calibration
QC
resistivity
Electrical resistance in ohms measured between opposite faces of a 1.00-cm cube of an aqueous solution at a specified temperature
describe culturing water
allow to run for 1 min
aliquoted and plated
CFUs are determined
water for some chemical tests where CLRW is not adequate
special reagent water (SRW)
CLRW
clinical laboratory reagent water
types of reagent water, purification, use
- type I —filtered, distilled, deionized multiple times —trace metal, iron, enzymes analyses
- type II —double distilled —reagents, QC, standards
- type III —washing glassware
least pure chemical grades
Practical
Technical
Commercial
ACS chemical grades
Analytical grade
Reagent grade
Ultrapure:
Spectrograde
Nanograde
HPLC grade
organization
Atomic weight standard (grade A)
Ultimate standard (grade B)
Primary standard (grade C)
Working standard (grade D)
Secondary substances (grade E)
International Union for Pure and Applied Chemistry (I U P A C)
Provides standard reference materials (SRMs) in solid, liquid, or gaseous form
National Institute of Standard and Testing (NIST)
impossible in clinical chemistry (versus analytical)
knowing the exact composition of the material
primary standard
Highly purified chemical that can be measured directly to produce a substance of exact known concentration and purity.
Assigned a value after careful analysis. Used to verify calibration or accuracy/bias. Used in clinical chemistry.
Standard Reference Materials (SRMs)
advantages of reagents coming in kits
- less human error/variability
- less time consuming
- less danger to techs (carcinogens)
- less storage space
types of glassware
- borosilicate
- corex
- low actinic
describe borosilicate glassware
- high degree of thermal resistance
- damaged by highly alkaline chemicals
- should not be heated
describe corex glassware
- strengthened chemically rather than thermally
- 6 times stronger than borosilicate
- resists clouding and scratching
describe low actinic glassware
- amber or red color protects light sensitive substances
- high thermal resistance
- used to contain reagents, control materials, calibrators
4 types of plasticware
- polypropylene
- polyethylene
- polycarbonate
- polystyrene
May be flexible or rigid
Chemically resistant
Can be autoclaved
polypropylene
Test tubes, bottles, graduated tubes, stoppers, disposable transfer pipettes, volumetric pipettes, and test-tube racks
May bind or absorb proteins, dyes, stains, and picric acid
polyethylene
Used in tubes for centrifugation, graduated cylinders, and flasks.
Broad temperature range: -100 to +160°C.
Verty strong plastic, but not suitable for strong acids, bases, and oxidizing agents
polycarbonate
Rigid, clear type of plastic
Should not be autoclaved
Used in capped graduated tubes and test tubes
Will crack and splinter when crushed
polystyrene
Almost chemically inert
Suitable for use at temperatures ranging from −270 to +255°C
Resistant to a wide range of chemical classes
Teflon
2 classes of pipettes
- volumetric (transfer)
- measuring