Inorganic phosphorus (phosphate ester) is one of the major constituents of bones. About 85% of the phosphorus is present in the skeletal system while the remaining 15% lies in other tissues. It is mainly responsible for the construction of bones and teeth. Similarly, it is also responsible for carbohydrate metabolism, the normal functioning of the nerve tissues, muscle contraction, etc. You can measure the level of inorganic phosphorus in the body by the molybdic acid method or the ammonium molybdate method in a laboratory. Here, we will be mainly discussing these two methods of testing.
Inorganic Phosphorus Normal Range
The range shown below is the normal range of inorganic phosphorus in the serum and urine of the patient. However, this is an approximate value and can differ from one laboratory to another. The method of testing and the reagents used for testing can alter the value in the laboratory. Similarly, geographical location, habitat, age, sex, etc, can also alter the value to some extent
- Children:- 4-7 mg/dl
- Adults:- 2.5 – 5 mg/dl
- Urine:- 300- 1000 mg/dl
An increase in the level of inorganic phosphorus can be the possible cause of liver diseases, bone metastasis, renal failures, and hypoparathyroidism. Similarly, a decreased level of phosphorus can be an indicator of hyperparathyroidism, Vitamin D deficiency, etc.
Thus, we can conclude that, if the level of inorganic phosphorus in the blood is abnormal you need to visit the doctor for further investigation.
Sources of Inorganic Phosphorus
Some of the natural sources of phosphorus are given below.
- Milk and milk products such as butter, cheese, etc.
- Whole grains such as barley and wheat
- Nuts. lentils, beans, etc
Ammonium Molybdate Method for Inorganic Phosphorus Measurement
1. Principle Reaction
Inorganic phosphorus reacts with ammonium molybdate in an acidic medium (eg, H2SO4) to form a colored phospho-molybdate complex. The intensity of this color is directly proportional to the concentration of the inorganic phosphorus. This is measured with the help of a semi-auto biochemistry analyzer.
2. Sample Preparation
The table shown below for inorganic phosphorus measurement is valid for the reagents of Tulip, Accurex, Analyticon, and Diasys Companies. So, if you have the reagent kit of any other company, then there can be minor fluctuation in the method.
If you have two reagents, then make a working solution out of them. The ratio of their composition will be given in the literature of your reagent kit or the reagent bottle. Else, a single reagent can also be found based on the company. In that case, that single reagent kit will act as a working solution for you.
For an external incubation, you can use an incubator or dry bath. For a reagent blank (Analyticon, Accurex, etc.), you can directly feed the working solution in a semi-auto biochemistry analyzer. In the case of Diasys or Tulip, you need to mix the working solution with the distilled water (equal to the sample volume used in making a sample test) for making a reagent blank.
Always remember that sipping volume < sample volume + reagent volume. So that means, make sufficient sample volume to feed into the semi-auto biochemistry analyzer. Else, it will suck up the air and will give the fault reading.
If the concentration of phosphorus is too high (out of range/ non-linear), then dilute the sample with 0.9% NaCl or distilled water at the ratio of 1:y. Finally, when you get the result, multiply the value with the dilution factor (1+y).
3. Programming of Inorganic Phosphorus in a Semi-auto Biochemistry Analyzer (Ammonium Molybdate Method)
Molybdic Acid Method for Inorganic Phosphorus Measurement
1. Principle Reaction
Inorganic phosphorus reacts with molybdic acid to form a blue-colored phosphomolybdic complex. The intensity of the color formed is directly proportional to the concentration of inorganic phosphorus present in the sample.
2. Sample Preparation
The table shown below for inorganic phosphorus measurement is valid for the reagent of Spinreact Company. So, if you have the reagent kit of any other company, then there can be minor fluctuation in the method.
In the case of reagent blank, directly feed the working reagent into the machine.
If the concentration of phosphorus in the sample is very high (out of range/ non-linear curve), then dilute the solution with 0.9% NaCl or distilled water at the ratio of 1:y. Finally, when you get the result, multiply it with the dilution factor (1+ y).
3. Programming of Inorganic Phosphorus in a Semi-auto Biochemistry Analyzer (Molybdic Acid Method)
Handling of the Inorganic Phosphorus Reagent
- Wear an apron and surgical gloves before carrying out the measurement.
- Look for the expiry date of the reagents during purchase and measurement time. Suppliers tend to give you reagent kits with a low expiry interval.
- Once you open the reagent bottles, the lifespan will decrease. So, look in your reagent kit literature for that.
- Bring the reagents and samples to room temperature before you can carry out any measurement.
- Always store reagents in the refrigerator when not in use.
Supplier of Inorganic Phosphorus Reagent
Mandawi Enterpises Pvt. Ltd is a distributor of reagent of Spinreact Company. It is located in Thapathali, Kathmandu. If you want to purchase the reagent, then you can contact the given number (+977 9849034738).