Vitamins

·          B & C are H₂O soluble; excreted rapidly in kidney; overdoses are rare

·          A,D,E, & K are fat soluble; stored; hypervitaminosis syndromes result

·         usually multiple deficiencies of Vit B exist (not single) so supplementation is in multiple combos

Thiamine (Vit B-1) – precursor for TPP which is required for decarboxylation of a-keto acids and is a co-

       factor for transketolase.

·          most common vitamin deficiency

·          Deficiency = Beri-Beri

·          The demand for TPP is related to the glucose state

Ø  IV glucose results in increased glucose metabolism that increases the need for thiamine

Ø  Hypermetabolic states also increase the need. (pregnancy, hyperthyroidism)

·          deficiency common in Alcoholics, pregnant women, the elderly, and “polished” rice diets

·          dry beri-beri

Ø  Peripheral neuropathy in pregnancy and alcoholics

Ø  Wernicke’s encephalopathy

Ø  Korsakoff’s psychosis

·          wet beri-beri

Ø  heart failure due to high output CHF

·          No toxicity from administration because it is not stored

 

Vitamin B-12 (Cyanocobalamin) – cofactor in formation of methionine and SAM from homocysteine

·          deficiency causes megaloblastic anemia and neurologic disease

Ø  deficiency results in

1)       trapping of folic acid in inactive form (CH₃-THF)

2)       abnormal nucleotide pools and disordered DNA synthesis

·          causes of Vit B-12 deficiency (remember pathway of absorption)

1)       Pernicious anemia – autoimmune syndrome that results in loss of parietal cell function and thus decreased intrinsic factor secretion

2)       Post-gastrectomy syndrome

3)       Ileal insufficiency – can be due to surgery or small bowel disease

·          Megaloblastic anemia due to impaired red cell maturation and shortened red cell survival

·          Neuritis and Encephalopathy due to interference with normal myelin metabolism which leads to IRREVERSIBLE impairment of spinal cord and cortical function

·          Therapy

Ø  Remember that B-12 deficiency is often due to malabsorption and thus it has to be via injection

Ø  No toxicity exists

Folic Acid – precursor of several folate derivatives that serve as co-factors for the enzymes involved in 4-carbon metabolism

·          very common in alcoholics

·          deficiency

1)       leads to megaloblastic anemia – like Vit B-12

2)       spina bifida and anencephaly

3)       leads to abnormalities in amino acid and purine synthesis

·          absorbed in the proximal intestine; enterohepatic recirculation of folate derivatives in important

·          Causes of deficiency

1)       small bowel disease (sprue) or surgery

2)       agents that interfere with enterohepatic circulation (alcohol)

·          DOES NOT cause the irreversible spinal cord and cortical injury characteristic of B-12 deficiency

·         Therapy – watch out for overlying B-12 deficiency; alcoholics; before pregnancy

 Pyridoxine (Vitamin B-6) – converted to pyridoxal phosphate, a cofactor in amino acid metabolism

·          Deficiency

1)       complication of INH therapy

2)       can be seen in severe malnutrition

3)       causes dermatitis, neuritis, and maybe carpal tunnel syndrome

·          Therapy

Ø  prophylaxis for those on INH therapy

Ø  CONTRA: Parkinson’s patients on L-DOPA therapy because it stimulates the activity of dopa decarboxylase in peripheral tissues

Niacin (B-3) – (Nicotinic Acid) precursor for NAD and NADP

·          Deficiency – Pellagra

1)       3 D’s of pellagra – Dermatitis, Dementia, and Diarrhea

2)       severely malnourished and alcoholics

3)       rare

·          Therapy

Ø  Uncomplicated

·          Syllabus listed it as B-5 that’s incorrect.  B-5 is pantothenic acid. Niacin is B-3

Riboflavin (B-2) – precursor for FMN and FAD which are cofactors for several respiratory enzymes

·          Deficiency

1)       dermatitis, neuritis

2)       no clinically distinctive features

·          Therapy

Ø  uncomplicated

Other B- Vitamins – Biotin, Pantothenic Acid, Choline, Carnitine

Vitamin C (Ascorbic Acid) – also a cofactor; protein hydroxylation reactions

·          used for:

1)       collagen synthesis

2)       GI iron absorption

3)       Anti-oxidant

·          Deficiency – Scurvy

1)       malnourished elderly and infants fed ascorbate deficient diet

2)       results in

a.        weakening of extracellular matrices

b.        hyperkeratosis of the skin

c.        petechia

d.        loosening of the teeth, gingivitis

e.        imparied wound healing

·          Treatment

Ø  for replacement, and anti-oxidant capabilities

Ø  no toxicity (remember that it is H₂O soluble), rapidly excreted by the kidney

·          Side effects from treatment with Vitamin C

1)       can give false + results in urine tests for glucose

2)       can suppress hematest for occult blood in stool

3)       if given in megadoses – diarrhea, renal damage 2^o to oxalate stones

 

Vitamin K  (Phytonadione) – cofactor for enzymes that carboxylate the amino acid side chains of blood clotting factors

·          Deficiency causes abnormal bleeding due to hypothrombinemia and has an increased PT time.

·          Sources of Deficiency

1)       prolonged antibiotic therapy

2)       malabsorption syndromes – esp those due to biliary insufficiency

3)       intestinal disease (sprue, regional enteritis, bowel resections

·          transient Vit K deficiency in the newborn is common

·          Therapy

Ø  phytonadione i.m. for standard deficiency

Ø  prophylactic therapy to normal newborns

 

Vitamin E (a-tocopherol) and the other anti-oxidants (Vit C and A)

·          thought to have its therapeutic effect via its ability to consume free radicals and reactive O₂ species

·          prevention of atherosclerosis

·          Vit E (a-tocopherol), Vitamin C (ascorbic acid) and b-carotene (Vit A precursor) serve as anti-oxidants by blocking free radical chain reactions and scavenging reactive oxygen and peroxide by-products

·          Vit E is lipid soluble and is transported in serum lipoproteins (makes it physically close to cholesterol)

Ø  Treatment with Vit E: exclusively in the treatment of patients w/ atherosclerosis

·          Vit A: may be protective against tobacco smoke and thus lung cancer.

·          Vit C: unclear

 

Vitamin D (Cholecalciferol) – more later

·          remember 1,25- (OH)₂-D₃ is active form

·          bind to nuclear hormone receptors

·         used pharmacologically to treat disorders of calcium and bone metabolism

Vitamin A (Retinoids) – In the eye, retinol is converted to retinaldehyde which is a cofactor in the conversion of opsin to rhodopsin.  Other tissues the retinol is converted to retinoic acid and binds to nuclear receptors and aids in the control of transcription of genes that regulate cellular growth and differentiation.

·          Retinol is derived from dietary b-carotene and retinyl esters

·          Effects on:

1)       vision

Ø  deficiency will lead to defective rhodopsin function and “night blindness”

2)       Cell Growth and Differentiation

Ø  physiological role in controlling proper growth and differentiation of tissues during embryogenesis

Ø  also, important in regulating the growth and differentiation of epithelial surfaces

·          Deficiency

1)       night blindness and xerophthalmia

2)       loss of barrier function of the respiratory and GI mucosa

3)       increased susceptibility to death from common infections

4)       takes years for adults to develop because the liver stores so much of it

5)       not too uncommon in the neonate esp. in foreign countries

·          Treatment

Ø  In US used for treatment of skin diseases and cancer

1)       Derm – Psoriasis , Acne, Keratinization disorders, Photo-aging

2)       Cancer – Leukemias (APL), leukoplakia

·          Hypervitaminosis A

Ø  occurs because the Vit A is stored in tissues and excessive ingestion can easily cause distinct toxicity

Ø  Teratogen – do not take if pregnant or likely to become pregnant

Ø  Skin and mucus membrane toxicity

Ø  Cerebral Edema – headache and increased ICP

Ø  Bone toxicity – bone spurs and fusion of the vertebral bodies

 

Classification of salivary glands

It is classified on the basis of the secretion

Serous gland

This type of gland is made-up of mucous cells

These glands secrete thin and watery saliva

Ex

Parotid gland

Mucous glands

This type of glands is made up of mucous cells

These glands secrete thick and viscous saliva with more mucin

Ex

Bucccal gland and Lingual mucous glands

Mixed glands

These glands are made up of both serous and mucous cells

Ex

Submandibular and sublingual glands

Parotid glands

Largest of salivary glands

Weights- 20-30 g

Located – At the face just below and in front of the ear

Each gland has a parotid duct opening into the moth at the level of the second upper molar tooth

Submandibular glands

Also called submaxillrty glands

Weight- 8-10 g

Located in sub maxillary triangle mediak to mandible

Duct  open on the floor of the mouth one on each side of the frenulum of the tongue

Sublingual glands

These are smallest glands

Weight – 2-3 g

Located in the mucosa at the floor of the mouth

They have numerous small ducts that open into the floor of the mouth

Secretion of saliva

Secretion of saliva is under autonomic nerve control

Parasympathetic stimulation causes vasodilatations and secretion of watery saliva with content of enzymes and other organic substances

Sympathetic stimulation causes vasoconstriction and secretion of small amounts of saliva rich in organic material

Reflex secretion occurs when there is food into the mouth

The reflex can easily become conditioned so that the sight , smell and the thought of food stimulates the flow of saliva  

Physical Pharmacy-Lab

DETERMINATION OF PERCENTAGE COMPOSITION OF UNKNOWN SOLUTION BY USING REFACTOMETER

AIM : To determine the percentage composition of unknown solution by using refractometer
REQUIREMENTS : Carbon tetra chloride (CCl4), Benzene, Xylene, Pipette, Beaker,
Abbeys Refractometer.
PRINCIPLE :
when a ray of light beam passes from one medium to another, it shows refraction i.e., changes in the path. If it passes from rarer to denser medium. Eg: air to water, it bends towards the normal, angle of incidence ‘i’ is more than the angle of refraction ‘r’ . According to snells law the refractive index ‘n’ of second media with respect to first is

η = sin i
Sin r
The velocity of light decreases when it passes through a denser medium. Hence the ratio in the equation may be written as the ratio of the velocities of light in two media.

η = velocity of light in vacuum
Velocity of light in medium

RI is greater than 1 for the substances denser than air because the velocity of light in air is always higher when compared to the value in denominator, liquids and mixture of liquids passes a characteristic refractive index, it is common physical and chemical properties of a liquid. Eg: CCl4 has low refractive index because of its interaction with light to delocalize to P-cloud..
RI of the mixture satisfies the algebraic sum of refractive index of individual components. When benzene is added to CCl4 the RI is increases so the proportion of benzene is linear. RI is taken on Y-axis and Percentage volumetric compositon of Benzene in CCl4 is taken on X-axis, Plotting the points gives a straight line. Liquids will form binary mixtures i.e., which are miscible in all proportions, which can be employed for this purpose.

The principle explained above is used to find % composition of Benzene in CCl4. RI of unknown liquid is determined experimentally % V/V of benzene in CCl4 of unknown mixtures can be obtained from the graph.

Factors influencing RI :
• RI varies with the wavelength and temperature.
• It is represented by n20. This symbol indicates that the RI has been determined at 200C using D line emission of Sodium (Na) at 589nm.
• Abbeys refractometer is commonly used to determine the refractive index.

Applications:
RI is used in
1. Substances can be identified.
2. Purity of the substances can be measured.
3. Concentration of one substances dissolved in another liquid can be determined.
4. Molar refraction Rm is used to predict structural features of the molecules. Rm can be calculated from refractive index values.
5. Dielectric constant and molar polarizability can be obtained from refractive index.

PROCEDURE :

1. Determine RI of CCl4.
2. Prepare solutions of Benzene in CCl4 by taking different proportions of Benzene.
3. Draw a graph by taking ‘n’ value on y-axis and % concentration on x-axis.
4. Determine RI of unknown sample.
5. Determine concentration of unknown sample from the graph.

REPORT: The concentration of unknown sample of CCl4 by using Abeys Refractometer was
found to be ________ .

S.No CCl4 volume in ml Benzene volume in ml % composition of benzene in CCl4 Refractive index

DETERMINATION OF PERCENTAGE COMPOSITION OF UNKNOWN SOLUTION BY USING REFACTOMETER

AIM : To determine the percentage composition of unknown solution by using refractometer

REQUIREMENTS : Carbon tetra chloride (CCl₄), Benzene, Xylene, Pipette, Beaker,

                                     Abbeys Refractometer.

PRINCIPLE :                        

              when a ray of light beam passes from one medium to another, it shows refraction i.e., changes in the path. If it passes from rarer to denser medium. Eg: air to water, it bends towards the normal, angle of incidence ‘i’ is more than the angle of refraction ‘r’ . According to snells law the refractive index ‘n’ of second media with respect to first is

                                                 η = sin i

                                                       Sin r

                         The velocity of light decreases when it passes through a denser medium. Hence the ratio in the equation may be written as the ratio of the velocities of light in two media.

                                               η = velocity of light in vacuum

                                                     Velocity of light in medium

                           RI is greater than 1 for the substances denser than air because the velocity of light in air is always higher when compared to the value in denominator, liquids and mixture of liquids passes a characteristic refractive index, it is common physical and chemical properties of a liquid. Eg: CCl₄ has low refractive index because of its interaction with light to delocalize to P-cloud..

                           RI of the mixture satisfies the algebraic sum of refractive index of individual components. When benzene is added to CCl₄ the RI is increases so the proportion of benzene is linear. RI is taken on Y-axis and Percentage volumetric compositon of Benzene in CCl₄ is taken on X-axis, Plotting the points gives a straight line. Liquids will form binary mixtures i.e., which are miscible in all proportions, which can be employed for this purpose.

                           The principle explained above is used to find % composition of Benzene in CCl₄. RI of unknown liquid is determined experimentally % V/V of benzene in CCl₄ of unknown mixtures can be obtained from the graph.

      Factors influencing RI :

·         RI  varies with the wavelength and temperature.

·         It is represented by n²⁰. This symbol indicates that the RI has been determined at 20⁰C using D line emission of Sodium (Na) at 589nm.

·          Abbeys refractometer is commonly used to determine the refractive index.

Applications:

                 RI is used in

1.      Substances can be identified.

2.      Purity of the substances can be measured.

3.      Concentration of one substances dissolved in another liquid can be determined.

4.      Molar refraction Rm is used to predict structural features of the molecules. Rm can be calculated from refractive index values.

5.      Dielectric constant and molar polarizability can be obtained from refractive index.

PROCEDURE :

1.      Determine RI of CCl_4.

2.      Prepare solutions of Benzene in CCl₄ by taking different proportions of Benzene.

3.      Draw a graph by taking ‘n’ value on y-axis and % concentration on x-axis.

4.      Determine RI of unknown sample.

5.      Determine concentration of unknown sample from the graph.

REPORT: The concentration of unknown sample of CCl₄ by using Abeys Refractometer was  

                   found to be ________ .

S.No	CCl4 volume in ml	Benzene volume in ml	% composition of benzene in CCl4	Refractive index

DETERMINATION OF SURFACE TENSION OF LIQUID USING DROP COUNT METHOD

AIM:- To determine the surface tension of the given liquid  by drop count method using       stalagmometer at room temperature

REQUIREMENTS:-stalagmometer, sample solution, acetone & water

PRINCIPLE:- Surface tension is defined as the force acting in dynes acting at right angles to the surface of liquid along 1 cm length of the surface . units of surface tensions is dynes/cm the magnitude of the  surface tension is the measure of strength of intra molecular attractive forces there are two forces determining surface tension of liquids .

They are 1.Drop weight method

               2.Drop count method by capillary method.

               Drop method is convenient and quick for this stalagmometer is used .surface tension measure the strength of cohesive forces of liquid. For example water has strong cohesive forces so surface tension is more on water other hand liquid such as benzene, have weak cohesive forces and have low surface tension   when compared to water. The lower the surface tension of the liquid the small of the size of the drop formed. Then more number of drops of found for the same volume of the liquid. Hence simply counting the number of drops for an unknown liquid and water is sufficient to calculate the surface tension.

PROCEDURE:

1.      Clean the stalagmometer  with distilled water and acetone and dry using hot air drier.

2.      Fits the stalagmometer to a stand in a vertical position.

3.      Dip the stalagmometer in a beaker of water (H₂O) and suck the water upto level higher than the position of the mark.

4.      Let the water flow down and count the number of drops passing between the upper and lower mark.Repeat the experiment thrice to get the number of drops be n₁.

5.      Remove water, clean, dry and repeat the procedure with the given liquid in the same manner thrice. Let the number of drops be n₂.

REPORT :

                  The surface tension of the given liquid by drop count method using stalagmometer was found to be ______________ dyne/cm.

S.No	NUMBER OF DROPS OF
	WATER	SAMPLE SOLUTION

DETERMINATION OF SURFACE TENSION OF LIQUID USING DROP WEIGHT METHOD

AIM:- To determine the surface tension of the given liquid  by drop weight method using       stalagmometer at room temperature

REQUIREMENTS:-stalagmometer, sample solution, acetone & water, sample weighing bottle.

PRINCIPLE:-

                        When a liquid is allowed to flow it form drops which increase in size from, it form drops which increase in size from the tip of the tube. The weight of the drop of a liquid is equal to the surface tension at the circumference of the tube.

PROCEDURE:

1.      Select a clean stalagmometer wash it with distilled water and acetone and dry using hot air drier.

2.      Dip the stalagmometer in a beaker of water (H₂O) and suck the water up to the upper mark A.

3.      Fits the stalagmometer to a stand in a vertical position.

4.      The liquid is allowed to flow to mark B and drops of liquid are collected in free air beaker.

5.      Repeat the experiment with water and weigh the drops of water formed between a fixed volume ( mark A-B).

6.      The surface tension is found using the equation

7.      Remove water, clean, dry and repeat the procedure with the given liquid in the same manner thrice. Let the number of drops be n₂.

REPORT :

                  The surface tension of the given liquid by drop weight method using stalagmometer was found to be ______________ dyne/cm.

DETERMINATION OF THE POROSITY OF THE GIVEN POWDER

AIM:  To determine the porosity of the given powder.

PRINCIPLE :  

                         Suppose a powder is placed in a graduated cylinder and the total volume is noted the volume occupied in the cylinder is known as ‘Bulk Volume’ V_b.

                         If the powder is known porous i.e., thus no internal forces and capillary spaces, the bulk volume of the powder consist of true volume of the solid particles and the volume of space between the particles. The volume occupied by the spaces is known as ‘Avoid Volume’.

V_b = V+Vt

V=V_b-Vt

                       The porosity of the powder is defined as ratio of wide volume to the bulk volume.

€=V_b-Vt

   V_b

              The porosity frequently expressed in percentage porosity = € X 100

PROCEDURE :

1.      Weigh 50gm of Calcium carbonate and starch and pass in a graduated cylinder.

2.      Note the volume initially occupied by the sample as Vb.

3.      Top the cylinder under constant time intervals and note the volume. After 50,100,200,300,,, tappings.

4.      At one stage we recognize the volume occupied is same after several tapings and the volume does in change on again taping also.

5.      Note the volume as true volume Vt.

6.      Porosity can be calculated by using the equation

7.      The noted readings then added to calibrated value gives the actual value. Repeat the procedure for different samples.

€=V_b-Vt

   V_b

  REPORT:

S.No	Name of the sample	Bulk Volume	No.of Tappings	True volume	Pure Volume	%porosity

DETERMINATION OF UNKNOWN CONCENTRATION OF NaCl SOLUTION USING CRITICAL SOLUTION TEMPERATURE

AIM: To determine the concentration of NaCl in a given solution using Critical Solution Temperature Method.

THEORY: Addition of substance to a partially miscible two liquids produces a system which contains three components. If the added material is soluble in only one of two liquids, the mutual solubility of the liquid phase is decreased. If the original solution as an upper critical solution temperature. The temperature is raised. Addition of naphthalene to a mixture of phenol and water results in an increase in the critical solution temperature. Since naphthalene is soluble only phenol, likewise, there is an increase critical solution temperature on adding NaCl to Phenol-Water system. Since NaCl is soluble only in water. If it has a lower consolute temperature, it is allowed by addition of third component. If the third component is soluble in both liquids roughly to the same extent, mutual solubility of liquid phase increases. The upper consolute temperature will be lowered or lower critical solution temperature will be raised. As a result, for e.g.: The addition of succinic acid or NaCl to phenol water system results in lowering of critical solution temperature.

PRINCIPLE: Addition of NaCl to phenol-Water system enhances its upper consolute temperature. The reasons are as follows:

                        NaCl is more soluble in water compared to its solubility in phenol in water layer. In the same way electrolyte present in the miscibility of aqueous layer in phenol layer. Therefore, temperature has to be increased to achieve mutual solubility. Therefore critical solution temperature of the system also increased. The increase in the critical solution temperature indirectly proportional to the concentration of NaCl. The linear relationship is used to determine the percentage composition of NaCl in water.

Applications:  

1. The addition of other ingredients to a conjugate solution may adversely effect their mutual solubility e.g.: Cresol with soap. According to B.P., 1968, contains 50% cresol. At this concentration, cresol is only partially miscible with water at room temperature. But the addition of soft soap to mixture makes cresol completely soluble in all proportions. This phenomenon is called as “SOLUBILISATION”. The principle is used in the preparation of phenolic disinfectant in water.
2. The critical solution temperature method can be used to determine the percentage of composition of added substance using phenol-water system.
3. It is possible to separate the liquids by the addition of third substance. The technique that is used here is applied for the extraction of drug in the analysis and body fluids.

GLASSWARE & CHEMICALS:

               Transition temperature apparatus, Thermometer (110^oC), beaker of 500ml, Volumetric flask of 100ml, pipette 10ml, gas burner, tripod stand, wire gauge, test tube, phenol, NaCl, weight box, fractional weight box.

PROCEDURE:

  Stock solution Phenol (80%w/v):

            Prepare 80%w/v of solution of phenol in water, by taking 20ml of water. At these proportions, water and phenol are completely miscible. This stock solution is used for the preparation of different concentration of phenol in water.

Stock solution, NaCl (1%w/v):

            Accurately weigh 1gm of NaCl and transfer into a 100ml volumetric flask. Add distilled water and dissolve the salt. Finally make up the volume to 100ml.

METHOD :

1. Prepare various concentration of NaCl ( 0.2%, 0.4%, 0.6%, 0.8%) in water (10ml) using the stock solution.
2. Take 5ml of phenol and 5ml of water into the transition tube, dtermine the miscibility temperature T₁.
3. Remove transition tmperature tube from waterbath and stirr to allow cooling. Note the temperature at which opalascence reappears T₂.
4. Determine the mean of T₁ & T₂ and record in table. The data represents the “0” concentration of NaCl solution.
5. Similarly, determine miscibility temperature of phenol-NaCl solution of various other concentrations of NaCl by following steps 3 & 4.
6. Plot the graph of miscibility temperature ( Y-axis) various percentage concentration of NaCl ( X-axis).
7. Determine miscibility temperature of unknown solution.
8. Estimate the percentage composition of NaCl in the unknown soluiton from the standard plot drawn carrier.

Report:

1. Critical solution temperature of unknown sample is __________ ^oC.
2. The percentage composition of NaCl in the given sample ( from graph ) is _________ %.

Table:

Vol of phenol	%conc of NaCl	Miscibility temp	Turbidity temp	Avg temp

ESTIMATION OF pH BY USING pH METER

AIM : To measure the pH of a prepared buffer solution using pH meter.

PRINCIPLE :

                 An electric potential is generated when a thin glass membrane seperates two solutions of different hydrogen ion concentration. Then a solution is kept measuring pH, the difference in the potential between that of glass electrode and reference electrode is measured amplified and converted into a direct pH reading on the meter.

                The pH meter measures the electromotive force (EMF) of concentrated cell formed from a reference electrodes, test solution and a glass electrode sensitive to hydrogen ion concentration. EMF og complete cell formed by linking of two electrodes i.e., glass electrode and calomel electrode is

E cell = E _ref – E _glass

Where E _ref = potential of calomel electrode

           E _glass= potential of glass electrode, which depends on pH of the solution.

APPARATUS:

               The pH meter consists of two electrodes

1.      Calomel Electrode

2.      Glass Electrode

               The glass electrode contains silver, AgCl₂ and 0.1N HCl. Its tip is covered by a special glass surface which allows only hydrogen ion to pass through it. Each of these component exists in an ionized state as follows

                                      Ag                     Ag⁺ + e^-

                Inspite of above reactions there exists a complex and delicate equilibrium in glass electrode.

                Calomel electrode contains mercury in contact with mercurous chloride which in turn is in contact with KCl solution at known concentration. The silver chloride electrode consists of silver wire coated with a deposit of KCl solution. In calomel electrode there is also a component that exist in delicate equilibrium

PROCEDURE:

          MEASURING OF pH OF ACIDIC SOLUTION:

                 When the electrodes are placeod in acidic solution a concentration of H⁺ ion present on the outside of glass membrane increases, as a result the holes on the outer hydrated surface of glass electode are occupied by H⁺ ions produce due to break down of HCl combines with Cl^- ions produce to give rise to the electrode potential, which is index of the pH of the solution.

         MEASUREMENT OF pH OF BASE SOLUTION:

                  When the electrodes are placed in a basic solution which has concentration of OH^- ions. The H⁺ ions from the outer hydrated layer if glass electrode leave their holes and combines with OH^- ions of sample solution to give water molecule. Since the outside the holes become wettened more and protons from (HCl) solution inside the glass electrodes become bounded to inner membrane there by developing excessive negative charge. This difference in charge and two sides of glass electrodes results in electrode potential and as a result the pH of solution has measured.

       MEASUREMENT OF pH  OF NEUTRAL SOLUTION:

                When an electrode is placed in a neutral solution, the  H⁺ ions forms HCl present inside the glass electrodes become bound to the inner hydrated surface. This results in the release of equal number of protons from the holes of outer hydrated surface.

PRECAUTIONS:

v  Before use of pH meter, it is needed to warm up atleast for 15min.

v  pH meter is calibrated before use by meabs of a standard buffer solution. If there is any deviation in the pH meter is adjusted to correct standard value. The electrode should be washed with distilled water before and after use and must not be touched.

v  The solution where pH has to measure should be stir well prior to its pH determination.

v  The new electrode must be soaked in oil molal/litre HCl and distilled water is added for several hours before use.

v  After use of electrode it should be kept in distilled water and are never allowed to dry up.

v  Thus the pH of any given solution can be determined by pH meter.

REFERENCE BOOKS:

1.      Practical Biochemistry by Srivastavi.

2.      David T.Plummer of practical Biochemistry.

PREPARATION OF FLOCCULATED AND DEFLOCCULATED SUSPENSION

AIM:  To prepare and evaluate flocculated and deflocculated suspensions..

PROCEDURE :

1.      Weigh 5gm of Calcium carbonate and place in mortar add sufficient water and titrate until  a smooth paste is obtained.

2.      Dilute the paste with more of water until it is pourable and transfer the suspension in to a graduated measuring cylinder.

3.      Rinse the mortar and pestle with sufficient number of times in order to transfer all the solids to the graduated measuring cylinder

4.      Make the volume with water upto 100ml similarly prepare a suspension of calcium carbonate with a suspending agent like tragacanth.

5.      By taking 0.5% of tragacanth aalong with calcium carbonate in first step.

6.      Shake both the suspensions simultaneously to obtain uniform distribution and set aside without any disturbances.

7.      Note the volume of the sediment with both suspensions at 0.5, 10,15,20,25,30,40,50 and 60 minutes.

8.      Calculate sedimentation value and plot a graph taking sedimentation value against time.

  REPORT:

S.No	Time in min	Volume of sediment without tragacanth	Volume of sediment with tragacanth	Sedimentation on volume without tragacanth	Sedimentate on volume with tragacanth.