Calcium with Arsenazo III (1,8-Dihydroxy-3,6-disulpho-2,7-naphthalene-bis
(azo)-dibenzenearsonic acid), at neutral pH, yields a blue colored complex.
The intensity of the colour formed is proportional to the calcium
concentration in the sample1,2,3
CLINICAL SIGNIFICANCE
Calcium is the most abundant and one of the most important minerals in the
human body. Approximately 99% of body calcium is found in bones.
A decrease in albumin level causes a decrease in serum calcium. Low levels
of calcium are found in hypoparathyroidism, pseudohypoparathyroidism,
vitamin D deficiency, malnutrition and intestinal malabsortion.
Among causes of hypercalcemia are cancers, large intake of vitamin D,
enhaced renal retention, osteoporosis, sarcosidosis, thyrotoxicosis,
hyperparathyroidism1,6,7
.
Clinical diagnosis should not be made on a single test result; it should
integrate clinical and other laboratory data.
REAGENTS
R
Arsenazo III
Imidazol Buffer pH 6.5
Arsenazo III
100 mmol/L
120 mmol/L
Optional SPINTROL H CAL
PRECAUTIONS
R: H360- May damage fertility or the unborn child.
CAL: H290-May be corrosive to metals.
Follow the precautionary statements given in MSDS and label of the
product.
PREPARATION
Ready to use.
STORAGE AND STABILITY
All the components of the kit are stable until the expiration date on the label
when stored tightly closed at 2-8ºC, protected from light and contaminations
are prevented during their use.
Do not use reagents over the expiration date.
Signs of reagent deterioration:
- Presence of particles and turbidity.
- Blank absorbance (A) at 650 nm
0.50.
ADDITIONAL EQUIPMENT
- Spectrophotometer or colorimeter measuring at 650 nm.
- Matched cuvettes 1.0 cm light path.
- General laboratory equipment (Note 1, 2)
.
NOTES
1. It is recommended to use disposable material. If glassware is used the
material should be scrupulously cleaned with diluted 1/1 HNO3 in water
and then thoroughly rinsed it with distilled water.
2. Most of the detergents and water softening products used in the
laboratories contains chelating agents. A defective rinsing will
invalidate the procedure.
3. Calibration with the aqueous standard may cause a systematic error
in automatic procedures. In these cases, it is recommended to use a
serum Calibrator.
4. Use clean disposable pipette tips for its dispensation.
5. SPINREACT has instruction sheets for several automatic
analyzers. Instructions for many of them are available on request.
SAMPLES
- Serum or plasma1
: Separated from cells as rapidly as possible. Blood
anticoagulants with oxalate or EDTA are not acceptable since these
chemicals will strongly chelate calcium.
- Urine1
: Collect 24 hours urine specimen in calcium free containers. The
collecting bottles should contain 10 ml of diluted Nitric acid (50% v/v).
Record the volume.
Dilute a sample 1/2 in distilled water. Mix. Multiply results by 2 (dilution
factor).
Stability of the samples: Calcium is stable 10 days at 2-8ºC.
