Showing posts with label Sops. Show all posts
Showing posts with label Sops. Show all posts

Thursday 14 March 2019

SOP for STANDARD WORKING PROCEDURE FOR ESTIMATION OF COPPER



SOP for STANDARD WORKING PROCEDURE FOR ESTIMATION OF CADMIUM

SOP for STANDARD WORKING PROCEDURE FOR ESTIMATION OF ARSENIC

SOP for ESTIMATION OF HEXAVALENT CHROMIUM



PRINCIPLE:
The hexavalent chromium is determined calorimetrically by reaction with diphenylcarbazide in 
acid solution. A red-violet colored complex of unknown composition is produced. The reaction
 is very sensitive, the molar absorptivity based on chromium being about 40000 Lg –1 cm-1 
at 540 nm.

MINIMUM DETECTION LIMIT:    0.05 mg/l


REAGENTS:

1.        Stock chromium solution: Dissolve 141.4 mg K2Cr2O7 water and dilute to 100 ml; 
1.00 ml = 500 µg Cr.
2.        Standard chromium solution: Dissolve 1.00 ml stock chromium solution to 100 ml; 
1.00 ml = 500 µg Cr.
3.        Phosphoric acid, H3PO, conc.
4.        Diphenylcarbazide solution: Dissolve 250 mg 1,5- diphenylcarbazide 
(1,5-diphenylcarbazide) in 50 ml acetone. Store in a brown bottle. Discard when solution
 becomes discolored. Chromium solution (5 mg/L) ranging from 2.00 to 20.0 ml, to give 
standards for 10 to 100 µg Cr, into 250-ml beakers or conical flasks. Proceed with 
subsequent treatment

PROCEDURE:

Preparation of calibration curve: To compensate for possible slight losses of  
chromium during digestion or other analytical operations, treat standards by the 
same procedure as the sample. Accordingly, pipette measured volumes of standard
 of standards as if they were samples, also carrying out cupferron treatment of standards 
if this is required for samples. Develop color as for samples, transfer a suitable portion of 
each colored solution to a 1-cm absorption cell, and measure absorbance at 540 nm, 
using reagent water as reference. Correct absorbance readings of standards by 
subtracting absorbance of a reagent blank carried through the method.

Color development and measurement: Add 0.25 ml (5 drops) H3PO4. Use 0.2 N 
H2SO  and a pH meter to adjust solution to pH 1.0 ± 0.3 the matter of pH range is 
currently being considered by standard methods. Transfer solution to a 100-ml volumetric 
flask, dilute to 100 ml, and mix. Add 2.0 ml diphenylcarbazide solution, mix, and let stand 
5 to 10 min for full color development. Transfer an appropriate portion to a 1-cm 
absorption cell and measure its absorbance at 540 nm, using reagent water as reference. 
Correct absorbance reading of sample by subtracting absorbance of a blank through 
the method. From the corrected absorbance, determine micrograms chromium 
present by reference to the calibration curve.


CALCULATION

HEXAVALENT CHROMIUM (mg/l)   =   ABS / SLOPE

REFERENCE:  APHA – 3500 Cr - B  Colorimetric Method

SOP for ESTIMATION OF SOLIDS


PRINCIPLE:

TOTAL SOLIDS (TS) – The sample is evaporated in a weighed dish on a steam
 bath and is dried to a constant mass in an oven either at 103 – 105°C or 
179 to 181°C. Total residue is calculated from increase in mass.

TOTAL DISSOLVED SOLIDS (TDS) – the sample is filtered and the filtrate 
evaporated in tared dish on steam bath. The residue after evaporation is dried
 to constant mass at 103 – 105°C.

MINIMUM DETECTION LIMIT(TDS): 5.0 mg/l

REQUIRMENT:

Filtration apparatus: Any one of the following can be used.

1.      Membrane filter funnel
2.      Gooch crucible, 25 ml to 40 ml capacity with Gooch crucible adapter.
3.      Filtration apparatus with reservoir and coarse (40 – 60 mm) fritted disk as filter support.
4.      Suction flask of sufficient capacity for sample size selected.
5.      Drying oven for operation at 180 ± 2 °C.
 
PROCEDURE:

PREPARATION:

Clean & thoroughly wash all the glassware’s with dilute Sulphuric acid. 
Rinse the glassware’s several times with distilled water. Dry the glassware’s in oven 
at 180oC for 1 hour. Keep them in desiccators for cooling. Weigh the cooled 
evaporating dishes (two nos.) initially. Note down the reading A (dish for TS) &
 B (dish for TDS).
Sample testing: Select volume of the sample, which has residue, contains 
approximately 100 to 200 mg. This value may be calculated from values of 
specific conductance. To obtain measurable residue if necessary, add successive
 sample portions to the same dish after evaporation.

Pipette this sample to previously weighed evaporating dish A (for TS). Filter the sample 
(20 ml /25 ml) using 0.45 m m membrane filter. Collect the filtrate in a clean beaker. 
Measure 10 ml or suitable aliquot of filtrate & transfer it to second evaporating
 dish B. Evaporate the water content completely using water bath / oven. If oven is used 
adjust the temp 103 – 105 oC. Cool the dishes in desiccators.

Weigh the cooled dishes. Again heat the samples at temperature 105oC for one hour 
and check the weight loss. If there is considerable difference in first observation and 
second one then repeat the heating till weight of dried sample remains constant 
in two consecutive observations & note down the reading (C-for without filtration & 
D-for filtrate).


OBSERVATIONS:

 1. Initial weight of evaporating
    dish for sample without filtration -------(A)   =                      g 
 2. Initial weight of evaporating
     dish for sample with filtration---------(B)     =                      g
 3. Final weight of evaporating
    dish for sample without filtration ------- (C)  =                     g
 4. Final weight of evaporating
     dish for sample with filtration ---------- (D)   =                    g

CALCULATIONS:
 
Total Solids (TS)
                                             C - A                 
                     mg/L  = ----------------------------- x 1000  x  1000
                                      ml of sample taken                            

Total Dissolved Solids (TDS)

                                              D - B
                TDS        = --------------------------------- x 1000  x  1000
                                     ml of sample taken

Total Suspended Solids (TSS) mg / l = TS mg / l – TDS mg / l

REFERANCE: IS : 3025 (Part 15 & 16) – 1984

DRY RESIDUE, DVS AND TVS


PROCEDURE:

After noting down the final weights of TS and TDS, keep the samples in muffled 
furnace at temperature 550oC for one hour.
Note down the final weights of the evaporating dishes.

OBSERVATION:

Final weight of TS evaporating dish        (E)       =                    g 
Final weight of TDS evaporating dish     (F)       =                     g


CALCULATIONS: 
1.    TVS
                                                                (C - A) - E
                        TVS mg/L       = -----------------------------------  x 1000 x 1000         
                                                            ml of sample taken

2.    DVS
                                                                  (D - B) - F
                        DVS mg/L      = ------------------------------------- x 1000 x 1000        
                                                            ml of sample taken


REFERENCE:  APHA –2540 Std. Methods for water and wastewater analysis

SOP for STANDARD WORKING PROCEDURE FOR ESTIMATION OF SILVER

SOP for STANDARD WORKING PROCEDURE FOR ESTIMATION OF SELENIUM

SOP for ESTIMATION OF PHOSPHORUS BY STANNOUS CHLORIDE METHOD




                PRINCIPLE:
Molybdophosphoric Acid is formed and reduced by stannous chloride to intensely
 coloured molybdenum blue.

                 MINIMUM DETECTION LIMIT:  3 µg P/l


                 REAGENTS:

1.    Phenolphthalein indicator aqueous solution.

2.    Strong acid solution: Slowly add 300 ml conc. H2SO4 to about 600 ml distilled 
water. When cool, add 4.0 ml conc. HNO3 and dilute to 1000 ml.

3.    Ammonium molybdate reagent: Dissolve 25 g ammonium molybdate in 175 ml
 distilled water. Cautiously add 280 ml conc. H2SO4 to 400 ml distilled water. 
Cool, add molybdate solution and dilute to 1000 ml.    

4.    Stannous chloride reagent: Dissolve 2.5 g fresh SnCl2. 2H2O in 100 ml glycerol.
 Heat in a water bath and stir with a glass rod to hasten dissolution. This reagent is
 stable and requires neither preservatives nor special storage.  

5.    Standard phosphate solution: Dissolve 219.5 mg anhydrous KH2PO4 and 
dilute with distilled water to 1000 ml.  (1ml.= 50 mg PO4

 PROCEDURE:



1.    Sample pretreatment: To 100 ml sample containing not more than 200 mg P and
 free from colour and turbidity. Add 0.05 ml (1 drop) phenolphthalein indicator. 
If sample turns pink add strong acid solution drop wise to discharge the colour. 
If more than 0.25 ml (5 drops) is required, take a smaller sample and dilute to 
100 ml with distilled water after first discharging the pink colour with acid. 

2.    Colour development: Add with through mixing after each addition, 
4.0 ml molybdate reagent and 0.5 ml stannous chloride. Rate of colour removal
 development and intensity of colour depend on temperature of the final solution.
 Each 1o C increases producing about 1 % increase in colour. Hence hold samples,
 standards and reagents within 2 o C of one another and in the 
temperature range between 20 oC and 30 oC.

3.    Colour measurement: After 10 min., but before 12 min. using 
it specified interval for all determinations.


Measure colour photo metrically at 690 nm and compare with calibration curve.
  
           CALCULATION:

                                      A                    B
     mg/L of P  =   ------------------- x -----------
                             ml of sample            C
  
Where,
            A = mg P determined from plotted curve,
            B = final volume of diluted sample (ml)
            C = Volume of diluted sample used for colour development (ml)

            REFERENCE: APHA – 4500 P D. Stannous chloride method

SOP for ESTIMATION OF NITRITE NITROGEN


PRINCIPLE:

Nitrite Nitrogen is determined through formation of a reddish purple azo-dye produced at              pH 2 – 2.5 by coupling diazotized sulphanalic acid with NED dihydrochloride.

MINIMUM DETECTION LIMIT: 0.01 mg/l



REAGENTS:

1.    Sulphanilamide reagent: Dissolve 5gm of the material in a mixture of 50ml of conc. hydrochloric acid & 300ml of water. Dilute to 500ml with water. The reagent is stable for several months.
2.    Sodium oxalate (0.05N): Dissolve 3.35 g Sodium oxalate, primary standard grade in water and dilute to 1000ml.
3.    Ferrous Ammonium Sulphate (0.05N): 19.607 g FAS plus 20 ml Conc. Sulfuric acid dilute to 1000 ml
4.    Stock nitrite solution: Dissolve 1.232 g Sodium nitrite in 1000 ml (250 ppm). Preserve it with 1 ml of chloroform.

5.    Standardization of stock nitrite solution:
Pipette out 50 ml standard (0.05M) KmnO4, 5 ml Conc. Sulfuric acid and 50 ml stock nitrite solution into a glass stopper flask or bottle. Submerge pipette tip well below permanganate acid solution while adding stock nitrite solution. Shake gently. Discharge permanganate colour by adding sufficient 10 ml portion of standard 0.05M FAS. Wait for 5 min.
Titrate excess FAS with 0.05 M KmnO4 to the faint pink end point. Carry a water blank through the entire procedure and make the necessary corrections in the final calculation as shown in the equation below.
Calculate nitrite content of stock solution
            [ (B x C) – (D x E)] x 7
 A =  ----------------------------------------
                                               F
           
Where,
                        A = mg nitrite nitrogen /L in stock solution
                        B = Total ml of standard KMnO4 used
                        C = Normality of standard KMnO4
                        E = Normality of standard reductant,
                        F = ml stock sodium nitrite solution taken for titration.
Each one ml potassium permanganate consume by sodium nitrite solution corresponds to 1750 g nitrite nitrogen.
           
6.    Intermediate nitrite solution: Calculate the volume G of stock nitrite solution required for the intermediate nitrite solution from G = 12.5/A. Dilute the volume G (approximately 50 ml) to 250 ml with water. (50 ppm). Prepared daily
7.    Standard nitrite solution: Dilute 10 ml intermediate nitrite solution to 1000 ml with water (0.5 ppm)
PROCEDURE:

Removal of suspended solids: If sample contains suspended solids remove it by passing sample through 0.45 mm membrane filter.
Colour development: If sample pH is not between 5 – 9, adjust to that range with 1 N HCl or NH4OH as required. To 50 ml sample or to a portion diluted to 50 ml add 2 ml colour reagent and mix.
Photometric measurement: Bet. 10 min and 2 hr. after adding colour reagent to samples and standards, measure absorbance at 543 nm.

CALCULATION:

Prepare a standard curve by plotting absorbance of standards against nitrite nitrogen concentration. Compute the sample concentration directly from curve.

Nitrite Nitrogen (as NO2-N) /l  =  µg NO2-N (in 52 ml of Final volume)
                                                                                       ml of Sample

REFERENCE: IS : 3025   ( Part 34 ) – 1988


requirement of Q.C in Daman

  We have requirement of Q.C Working area : Daman/Dalwada Exp: Fresher Gender: Male Qualification: Any Graduated Interested Person Call On t...