Unit 2: Elecytolytes Flashcards
DETERMINATION OF OSMOLALITY
Spx
Serum
Urine
OSMOLALITY
METHODS
Osmometers
Osmometer principle
Freezing point depression
Major cation of extracellular fluid
o 90% of all extracellular cation
o Most abundant
SODIUM (NATRIUM)
Most common electrolyte disorder in hospitalized and non-
hospitalized.
Hyponatremia
Decreased sodium levels may be caused by:
increased
sodium loss, increased water retention, or water imbalance
Increased sodium loss
oCertain diuretics (thiazides)
o Ketonuria
o Salt-losing nephropathy
o K+ deficiency
o Prolonged vomiting and diarrhea
o Severe burns
Increased water retention
o Acute or chronic renal failure
o Nephrotic syndrome
o Hepatic cirrhosis
o Congestive heart failure
• Water imbalance
o Excess water intake; Polydipsia
o SIADH (Syndrome of inappropriate ADH secretion)
o Pseudohyponatremia
o Diabetes mellitus
o excess levels of glucose in the
plasma or serum
Hyponatremia with a high osmolality
Increase in non-sodium cations
Hyponatremia with a normal osmolality
sodium loss or water retention
Hyponatremia with a low osmolality
Sodium Spx
Serum, plasma, and urine
Sodium
anticoagulants
lithium heparin, ammonium heparin, and lithium oxalate
Urine sodium analysis spx
24 hr collection
Used for sodium determination
Sweat
Methods in Sodium
ION SELECTIVE ELECTRODES
COLORIMETRY
Others
Emission Flame Photometry
Atomic Absorption Spectrometry (AAS)
The major intracellular cation in the body
POTASSIUM (KALIUM)
Spx in potassium determination
Seru
Plasma
Urine
Sodium
Ion Selective Exchange
Glass ion exchange
SODIUM
2 types of ISE method
Direct
Indirect
undiluted sample interacts with the ISE membrane (glass aluminum
silicate)
ISE DIRECT METHOD
DIRECT ISE MEMBRANE
Glass aluminum silicate
a diluted sample is used for measurement
ISE INDIRECT METHOD
Sodium
Colorimetry
ALBANESE LEIN
Albanese Lein color
yellow
Sodium is precipitated as Sodium uranyl zinc acetate
COLORIMETRY
ALBENESE LEIN
Potassium
Anticoagulant
Heparin
Potassium
Methods
ISE
COLORIMETRY
Emission Flame Photometry (EFP)Atomic Absorption Spectrometry (AAS)
Potassium
COLORIMETRY
Lockhead and purcell
Lockhead and purcell product
Blue color
the major extracellular anion
Chloride
Chloride
Methods
ION SELECTIVE ELECTRODE (ISE)
MERCURIMETRIC TITRATION (SCHALES AND SCHALES)
SPECTROPHOTOMETRIC METHODS
AMPEROMETRIC-COULORIMETRIC TITRATION
GIBSON AND COOKE
Chloride
ION SELECTIVE ELECTRODE (ISE) membrane
: tri-n-octylpropylammonium chloride decanol
protein-free filtrate of specimen is titrated with mercuric nitrate solution
MERCURIMETRIC TITRATION (SCHALES AND SCHALES)
MERCURIMETRIC TITRATION (SCHALES AND SCHALES) indicator
diphenylcarbazone
MERCURIMETRIC TITRATION (SCHALES AND SCHALES) end product
mercuric chloride (blue-violet complex)
Chloride
SPECTROPHOTOMETRIC METHODS
Mercuric Thiocyanate (Whitehorn titration Method)
Ferric Perchlorate
Mercuric Thiocyanate (Whitehorn titration Method)
Emd product
Reddish complex
Ferric Perchlorate
Colored complex
AMPEROMETRIC-COULORIMETRIC TITRATION
Cotlove Chloridometer
Silver ions usually react with chloride and to produce silver chloride
Cotlove chloridometere
Sweat chloride
GIBSON AND COOKE
Second most abundant anion in the ECF
BICARBONATE
• metabolic acidosis
o Compensatory Mechanism:
Hyperventilation
• metabolic alkalosis
o Compensatory Mechanism:
Hypo ventilation
Bicarbonate spx
Serum or plasma
Bicarbonate
Methods
ION SELECTIVE ELECTRODE
Enzymatic method
Bicarbonate enzymatic method
carboxylate phosphoenolpyruvate (PEP) and malate dehydrogenase
Fourth most abundant cation in the body
• Second most abundant intracellular cation
Magnesium
Magnesium reference method
ATOMIC ABSORPTION SPECTROPHOTOMETRY (AAS)
Methods magnesium
ATOMIC ABSORPTION SPECTROPHOTOMETRY (AAS)
EFFECTIVE FRAGMENT POTENTIAL (EFP)
ION-SELECTIVE ELECTRODE (ISE)
COLORIMETRIC METHODS
DYE – LAKE METHOD
Magnesium colorimetric methods
Calmagite
Formazan dye
Methylthymol blue method
Calmagite
EP
Wavelength
reddish-violet complex
532 nm
Formazan dye
EP
Wl
Colored complex
660nm
Methylthymol blue method
Ep
colored complex
DYE – LAKE METHOD
Titan yellow dye
• 99% is part of the bone and 1% is in the blood and ECF
• Is maximally absorbed in the duodenum (an acidic pH)
Calcium
Total Calcium Analysis
• COLORIMETRIC METHODS
Ortho-cresolphthalein Complexone (CPC)
Ortho-cresolphthalein Complexone (CPC)
Uses —— to prevent magnesium interference
8-hydroxyquinoline
Magnesium reference method
ATOMIC ABSORPTION SPECTROPHOTOMETRY (AAS)
Ionized Calcium
ION SELECTIVE ELECTRODE (LIQUID MEMBRANE)
Precipitation And Redox Titration
CLARK COLLIP PRECIPITATION
FERRO HAM CHLORANILIC ACID PRECIPITATION
CLARK COLLIP PRECIPITATION
o EP: Oxalic acid
o Color: purple color
FERRO HAM CHLORANILIC ACID PRECIPITATION
o EP: Choranilic acid
o Color: purple color
compounds participate in many of the most important biochemical processes :
Phosphate
Phosphate methods
AMMONIUM MOLYBDATE METHOD
• Fiske Subbarow Method
Fiske Subbarow Method
o EP: ammonium phosphomolybdate complex
o Color: colorless
