1. Identification of Normal Physical and Chemical Urine Constituents
T.A. Bahiya Osrah

2. These substances can be affected by different factors such as
Urine is ultra filtration of plasma, It carriers substances such as waste products and chemical substances excreted from the body by the kidney.
These substances can be affected by different factors such as
dietary intake
body metabolism
other factors.
From urine sample you can determine all metabolites in body.

3. Constituents of urine

4. Urine analysis It consists of a group of screening tests performed.
It includes both macroscopic and microscopic analysis.
First, the physical characteristics of the urine are noted and recorded.
Second, a series of chemical tests is run.
Third, the urine sediment is examined under the microscope to identify the components of the urinary sediments.

5. Types of urine specimens: There are basically four types of urine specimens: 1. First morning specimen 2. Random urine specimen 3. Fractional collection 4. Timed collection

6. Sample Collections Rules
Initial morning sample is preferred, particularly for protein analysis, because they are more concentrated from overnight retention in the bladder.
- The sample should be collected in a clean container.
- It must be analyzed within 1h of collection if held at room temp. or else refrigerated at 2C to 8C for not more than 8 hours before analysis.
- If not assayed within these time limits, several changes will occur.
The urine container must be sterile if the urine is to be cultured.
For microscopic examination, the urine must be fresh.

7. Urine Reports
Microscopic
Macroscopic
Physical
Chemical

8. Macroscopic Physical Characteristics
Appearance
Colour:
Colour intensity of urine correlates with concentration, the darker colour, lead to more concentrated is the sample.
Amber yellow > Urochrome (derivative urobilin, the end product of bilirubin degradation) a pigment found in normal urine.
Colourless > Reduced concentration.
Silvery sheen or milky appearance > bacteria or epithelial cells
Reddish brown > Blood (hemoglobin).
Yellow foam > Bile or medications.
Orange, green, blue or red > medications.

9. Macroscopic Physical Characteristics
Transparency: This is classified as clear and turbid. The degree of cloudiness of urine depends on both its pH and its dissolved solids composition. In normal urine, the main cause of cloudiness is crystals and epithelial cells. Turbidity may be due to gross bacteriuria, whereas smoky appearance is seen in hematouria. Threadlike cloudiness is observed when the sample is full of mucus. In pathological urine, it is due to pus, blood and bacteria.

10. Odour: Odour ordinarily has a little diagnostic significance
Odour: Odour ordinarily has a little diagnostic significance. Aromatic odour------> Normal urine due to aromatic acids. Ammonical odour > On standing due to decomposition of urea. Fruity odour > Diabetes due to the presence of ketones.

11. Volume: Urine volume measurements are part of the assessment for fluid balance and kidney functions. Most adults produce from 750ml-2500ml / 24h, with the average of about 1.5 L per person.

12. Reaction (pH): The pH is a measure of how acidic or alkaline (basic) the urine is. Normal urine pH falls within the range of Increased acidity in urine > Diabetes mellitus and some medications. The urine must be fresh (why?), because tendency of urine to be alkaline (as a result of ammonia liberation) on standing.

13. Normal Chemical Constituents of Urine
Urea: 1ml urine + 3ml NaOCl (sodium hypochlorite) =======> Evolution of N2 gas. URIC ACID (UA): 1ml urine ml 10% NaOH + 1ml Folin`s reagent ======> Blue colour. Creatinine: 1ml urine + drops of sat. picric acid + drops of NaOH 10% ========> deep red colour of creatinine ppt. On acidifying with HCl, the colour changes to yellow. Chloride: 1 ml urine + drops dil. HNO3 add 1 ml AgNO3 =====> white ppt. of AgCl is formed which can be dissolved in NH4OH. Cl- + AgNO3 =========> AgCl + NO3

14. Normal Chemical Constituents of Urine
Phosphate:
1 ml urine + 1 ml conc. HNO3 + 1 ml ammonium
Molybdate =====> Yellow colour.
Carbonate:
1 ml urine + drops conc. HCl =======> Effervescence
Na2CO3 + 2HCl =======> H2O + 2NaCl + CO2
Ammonia:
Make the urine just alkaline with NaOH. Close the tube with a cork containing another side tube dipped in Nessler's reagent. Heat the urine and then notice the evolving of NH3 in Nessler's reagent – Detect NH3 by its odour.
ml urine + 1ml phenol + 1ml NaBr =======> Blue color.
Sulphates:
1ml urine + 2 drops conc. HCl + few drops BaCl2 =======> White ppt. of BaSO4.
SO4 + BaCl2 =====> BaSO4 + 2Cl-