Unit 1

• assessing, setting or correcting a device usually by comparing or adjusting it to match or conform to a reliable, known, and unvarying measure

Actual process used to calibrate a device

• Resistivity • microbiological impurities, colony forming units per mL • organic, total organic carbon (T O C), • silicates • particulates

• review the criteria established by CLSI • ensure all appropriate filters and components are included • determine source of feed water or tap water that will be purified —> may contain unique contaminate or may have high mineral content (hardness) —> will often require the inclusion of additional components to remove these substances

1) purification 2) distillation 3) Resistivity 4) Reverse osmosis (RO) 5) deionization

• traps any particulates before the water is sent on to the next process

• liquid is vaporized and condensed to purify or concentrate a substance • water that is only distilled does not meet the specific resistivity requirements for CLRW

• electrical resistance in ohms measured between opposite faces of a 1.00-cm cube of an Aqueous solution at a specified temperature for CLRW

• water is forced through a semipermeable membrane that acts as a molecular filter. • removes —> 95-99% of organic compounds, bacteria and other particulate matter —> approximately 95% of all ionized and dissolved minerals (but will not remove gaseous impurities) -RO alone does not result in the production of CLRW

• passing water through insoluble resin polymers that contain either anion- or cation-exchange resins • the resins exchange hydrogen ions (H+) and hydroxyl (OH-) ions for ionized impurities in the water

• contains activated charcoal • helps remove organic compounds

• purity must be monitored on a consistent basis • at a minimum, resistivity and bacterial content should be monitored on a consistent basis —> most water-filtration systems will have a Resistivity meter —> for bacterial contamination, water should be allowed to run from at least one minute —> aliquot of water is obtained and plated onto an appropriate growth medium —> number of colony-forming units on the agar plate is determined

• preparations of reagents • as a diluent for controls and calibrators • to flush and clean internal components of analyzers • to serve as a medium in heating bath to incubate cuvettes, • to wash and rinse laboratory glassware, • advisable to use only CLRW water for most laboratory procedures • when special chemistry testing is required, should use special reagent water (SRW) and CLRW

• composition of feed water • availability of staff to perform the test • amount of water used in the lab

• can be added at the end of system • has an extremely small pore size

Lower

10 M^ . Cm (I tried)

• exist in varying degrees of purity • chemicals acquired for reagent preparation are characterized by a grading system —> greatly influenced by purity —> type and purity is usually stated on the label affixed to the chemical container

• practical • technical • commercial

• analytical grade (AG) • reagent grade (RG)

• spectrograde • nanograde • HPLC grade

• are produced to meet the specification defined in the: —> The United States Pharmacopoeia (USP) —> The National Formulary —> The Food chemical index -

• atomic weight standard (grade A) • ultimate standard (grade B) • primary standard (grade C) • working standard (grade D) • secondary substance (grade E)

• good source for highly purified chemicals, especially for reference materials • defines its chemical and physical properties for each compound • provides certificate documenting their measurements • provides standard reference materials (SRMs) in solid, liquid or gaseous form