SODIUM - LINEAR CHEMICALS

SODIUM
REF 1151010
2 x 60 mL
CONTENTS
R1. Reagent 1 x 60 mL
R2. Reagent 1 x 60 mL
CAL. Standard 1 x 2 mL
For in vitro diagnostic use only
SODIUM
Colorimetric method
ENDPOINT
PRINCIPLE
The sodium and the protein in the serum are precipitated with
magnesium uranyl acetate. After separation by centrifugation the
excess of uranyl ions in the supernatant react with thioglycolic acid
forming a colored complex which absorbance varies inversely to the
concentration of sodium in the sample. 1,2
II . Colorimetry
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Timer.
Photometer or colorimeter capable of measuring absorbance at
410 ± 10 nm.
R1
R2
CAL
REAGENT COMPOSITION
Precipitating. Uranyl acetate 19 mmol/L, Magnesium acetate
140 mmmol/L in ethyl alcohol.
X n F R 11-20/22-33 S 1/2-7-16-20/21-45
Color reagent. Ammonium thioglycolate 550 mmol/L, Amonia
550 mmol/L.
T R 25-36/37/38-43 S 1/2 –9-16-25-26-27-28-36/37/39-45-
61.
Sodium standard. Sodium (Na + ) 150 mmol/L. Concentration
value is traceable to Standard Reference Material 909b.
STORAGE AND STABILITY
PROCEDURE
I. Precipitation
1. Pipette into labelled centrifuge tubes:
TUBE
Sample
Standard
Sample 50 μl --
CAL -- 50 μl
R1
3.0 mL
3.0 mL
Store the reagents at room temperature 15-30ºC in the dark.
The reagents are stable until the expiry date stated on the label.
Turbidity may be a sign of contamination.
Discard If appear signs of deterioration:
- Presence of particles and turbidity.
- Blank absorbance (A) at 405 nm > 1.200 in 1cm cuvette.
REAGENT PREPARATION
The Reagents and Standards are are ready-to-use.
SAMPLES
Serum.
Sodium is stable for at least 24 hours at room temperature and 2
weeks when refrigerated. 3,4
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INTERFERENCES
Bilirubin (40 mg/dL) does not interfere.
Hemoglobin (500 mg/dL) does not interfere.
Ascorbate (20 mg/dL) does not interfere
Other drugs and substances may interfere. 5,6
I. Precipitation
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MATERIALS REQUIRED
Pipettes.
Centrifuge tubes (13 x 100 m/m).
Vortex mixer.
Desktop centrifuge / Microcentrifuge.
2.
3.
4.
5.
Mix well. Allow to stand for 5 minutes.
Vortex intensively for at least 30 sec. Allow to stand for 30 min.
Centrifuge for 5-10 minutes at 5000-8000 r.p.m., or 2 minutes
at 12000 r.p.m. (Microcentrifuge).
Separate off the clear supernatant.
II. Colorimetry
1. Pipette into labelled tubes:
TUBE
Blank
Sample
Standard
R1 50 μl -- --
Supernatant -- 50 μl 50 μl
2.
3.
R2 3.0 mL 3.0 mL 3.0 mL
Mix well and let stand the tubes for at least 5 minutes at room
temperature.
Read the absorbance of the blank (A BK ), the sample (A S ) and
the standard (A STD ) at 405 nm against distilled water.
The turbidity is stable for 30 minutes.
A BK – A S
A BK – A STD
CALCULATIONS
x C STANDARD = mmol/L (mEq/L)
Samples with values above 300 mmol/L should be diluted 1:1 with
distilled water. Multiply the results by 2.
QUALITY SYSTEM CERTIFIED
ISO 9001 ISO 13485
LINEAR CHEMICALS S.L. Joaquim Costa 18 2ª planta. 08390 Montgat, Barcelona, SPAIN
Telf. (+34) 934 694 990 Fax. (+34) 934 693 435. website www.linear.es

135-155 mmol/L (mEq/L).
REFERENCE VALUES 3,4
QUALITY CONTROL
To ensure adequate quality control (QC), each run should include a
set of controls (normal and abnormal) with assayed values handled
as unknowns.
- Correlation: This assay (y) was compared with a similar commercial
method (x). The results were:
N = 33 r = 0.998 y = 1.022x – 2.07
X Media = 153.53 mmol/L
Y Media = 136.5 mmol/L
The analytical performances have been generated using on automatic
instrument. Results may vary depending on the instrument.
REF
1980005 HUMAN MULTISERA NORMAL
Borderline level of sodium. Assayed.
REFERENCES
REF
1985005 HUMAN MULTISERA ABNORMAL
Elevated level of sodium. Assayed.
CLINICAL SIGNIFICANCE
Sodium is the major cation of extracellular fluid. It plays a central role
in the maintenance of the normal distribution of water and the osmotic
pressure in the various fluid compartments. The main source of body
sodium is sodium chloride contained in ingested foods. Only about
one-third of the total body’s sodium is contained in the skeleton since
most of it is contained in the extracellular body fluids. 1,2
Hyponatremia (low serum sodium level) is found in a variety
of conditions including the following: severe polyuria,
metabolic acidosis, Addison's disease, diarrhea, and renal tubular
disease. Hypernatremia (increased serum sodium level) is found in
the following conditions: hyperadrenalism, severe dehydration,
diabetic coma after therapy with insulin, excess treatment with
sodium salts. 3,4
1.
2.
3.
4.
5.
6.
Trinder, P. Analyst, 76:596, (1951).
Maruna RFL. Clin. Chem Acta, 2:581, (1958).
Tietz, N.W., Fundamentals of Clinical Chemistry, W.B. Saunder
Co., Phila, PA, p. 874.
Henry R.F., et. al., Clinical Chemistry Principles and Technics,
2nd Ed., Harper and Row, Hagerstein, M.D., (1974).
Young DS. Effects of drugs on clinical laboratory tests, 5th
ed. AACC Press, 2000.
Friedman and Young. Effects of disease on clinical laboratory
tests, 5 th AACC Press 2000.
NOTES
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Do not pipette the solution by mouth. Avoid ingestion/contact.
Specimens should be considered infectious and handled
appropriately.
When preparing filtrates, inadequate shaking or centrifugation
will cause falsely lowered test results.
Blood calcium, chloride, and potassium levels of up to 3 times
the normal reportedly exert no adverse influence on the
procedure; phosphorus levels exceeding 5 times the normal
likewise present no problems.
The Color reagent, becomes discoloured when exposed to the
light. Store protected from light. A slight turbidity does not affect
the determination.
Detergents usually contain high sodium concentrations. The
equipment – test tubes, pipettes, stoppers, cuvettes – must
therefore be rinsed carefully with distilled water.
Disposable plastic tubes are recommended for the determination.
Use Parafilm or plastic stoppers to close the tubes.
ANALYTICAL PERFORMANCE
- Linearity : Up to 300 mmol/L
- Precision:
mmol/L Within-run Between-run
Mean 94.1 155.8 198.9 94.1 155.8 198.9
SD 2.01 1.39 0.80 4.02 5.40 6.69
CV% 2.13 0.89 0.40 4.28 3.47 3.37
N 6 6 6 10 10 10
- Sensitivity : 1.5 mA / mmol/L sodium.
B1151-1/0504
R1.ing
QUALITY SYSTEM CERTIFIED
ISO 9001 ISO 13485
LINEAR CHEMICALS S.L. Joaquim Costa 18 2ª planta. 08390 Montgat, Barcelona, SPAIN
Telf. (+34) 934 694 990 Fax. (+34) 934 693 435. website www.linear.es