Form a red-violet complex The intensity of the color produced is compared with that obtained by treating a known quantity of iron under the same conditions. Reagents: Ammonium thioglycolate solution: Dissolve 20 g of thioglycolic acid and 20 g of ammonium chloride in water and dilute to 100 ml. Standard iron solution: Dissolve 0.1 g of iron wire in dilute hydrochloric acid, add 5 ml of hydrochloric acid and dilute to 1000 ml with water. 1 ml contains 10 μg of iron. Procedure: Pip

1. Continued………
Seminar on
Presented by
Sudip Kumar C. modh
PA/2010/11

2. 2
Introduction
Why limit test????
inorganic impurities are toxic at low levels, and these impurities should be monitored
to ensure safety
 Sources of inorganic impurities include those that are deliberately added to the
process (e.g., catalysts),
undetected contaminants from starting materials or reagents
leaching from pipes and other equipment
from naturally derived plant or mineral sources
the level of each inorganic impurity should not exceed the limit defined in or
otherwise specified in the individual monograph.
SUDIP KUMAR

3. 3
ICH Q3A
Impurities in Drug Substances guidance, impurities are classified
as organic, inorganic, and residual solvents
Classification of metal impurities…...
SUDIP KUMAR

4. WHAT TO BE DISCUSSED……… 4
Limit test of heavy metals
Limit test for Iron
Limit test of sulphated ash
Limit test for total ash
 Total Organic Carbon
Limit test of N,N- Dimethylaniline
Limit Test for Fluorides
Cadmium, copper, iron, lead, nickel and zinc
Limit test for selenium
Limit Test for Magnesium
Limit test of arsenic and mercury
SUDIP KUMAR

5. 5
Limit test of heavy metals: ( 2.3.13.)
IP (GENERAL NOTICES)
Tests with numerical limits and assays, quantity stated to be taken for testing is
approximate
amount actually used, which may deviate by not more than 10 per cent from that stated, is
accurately weighed or measured
result of analysis is calculated from this exact quantity..
In tests where the limit is not numerical but usually depends upon comparison with the
behaviour of a reference in the same conditions, the stated quantity is taken for testing.
Reagents are used in the prescribed amounts.
SUDIP KUMAR

6. 6
Limit test of heavy metals:
IP ( 2.3.13.)
Limit for heavy metals is indicated in in terms of
ppm, i.e., the parts of lead, Pb, per million parts (by weight) of the substance under
examination
Lead Nitrate Stock Solution: 0.1598 g of lead nitrate in (100 ml of water +1 ml of nitric
acid) dilute to 1000 ml with water
Lead Standard Solution:
Dilute 10 ml of lead nitrate stock solution with water to
100 ml
Each mL of Standard Lead Solution contains ≡ 10 µg of lead
SUDIP KUMAR

7. 7
Limit test of heavy metals:
USP <231>
 metallic impurities tare colored by sulfide ion, under specified test conditions,
not exceed limit specified in the individual monograph as a
percentage (by weight) of lead in test substance
 Determination by concomitant visual comparison with control (Standard Lead
Solution)#
Determine the amount of heavy metals by Method I, unless otherwise specified in
the individual monograph
. Types of methods Nature of substances
Method I that yield clear, colourless preparations
Method II do not yield under test conditions for Method I, or
form complex , interfere with precipitation by
sulfide ion, or for fixed and volatile oils
Method III wet-digestion method, when Method I nor Method
II can be used
#[note—Substances that typically will respond to this test are lead, mercury, bismuth, arsenic, antimony, tin, cadmium, silver,
copper, and molybdenum.]
SUDIP KUMAR

8. 8
USP <231>
Monitor Preparation
Test Preparation +2.0 mL of Standard Lead Solution
Lead Nitrate Stock Solution
Standard Lead Solution as per IP
Limit test of heavy metals:
BP (Ph. Eur. method 2.4.8)
Lead Nitrate Stock Solution
Standard Lead Solution as per IP
Blank solution: 10 ml of water R and 2 ml of the test solution
Methods Developed By Thioacetamide Reagent R
Sodium Sulphide Solution R1 (0.1 Ml) as Alternative
If Sodium Sulphide Solution R1 Is Used Instead, To Be Include For Methods A And B
Monitor solution
Same quantity prescribed for the test + volume of lead standard solution prescribed
for preparation of the reference solution
Apparatus for limit test of heavy metals:
spots on the filters obtained with the different solutions
SUDIP KUMAR

9. 9
Limit test of heavy metals:
BP (Ph. Eur. method 2.4.8)
Apparatus for limit test of heavy metals
SUDIP KUMAR

10. IP BP USP 10
Method A Method A Method I
Standard solution: Reference solution Standard Preparation
Into a 50-ml Nessler cylinder (standard) A mixture of 10 Into a 50-mL colour-
ml of lead standard solution comparison tube
(1 ppm Pb or 2 ppm Pb) R,
pipette 1.0 ml of lead std as prescribed, and 2 ml of
solution (20 ppm Pb)dilute prescribed aqueous solution pipette 2 mL of Std Lead
with water to 25 ml of substance to be examined Solution (20 µg of Pb), and
dilute with water to 25 ml
Adjust with dilute acetic acid
(1 N CH3COOH) or dilute adjust with 1 N acetic acid or
ammonia solution (10 per 6 N ammonium hydroxide to
cent w/w of NH3) to pH a pH between 3.0 and 4.0,
between 3.0 and 4.0, dilute dilute with water to 40 mL,
with water to 35 ml and mix. and mix
pH meter or short-range pH
indicator paper as external
indicator,
SUDIP KUMAR

11. IP Method A BP Method A USP Method I 11
Test solution: Test solution: Test Preparation:
In 50-ml Nessler cylinder 12 ml of the prescribed In 50-mL color-comparison
place 25 ml of Solution for aqueous solution of the tube, place 25 mL of the
test or dissolve specified substance to be examined solution prepared for the test
quantity of test substance in or, using the designated
sufficient water to produce volume of acid where
25 ml specified in the individual
monograph, dissolve in and
Adjust with dilute acetic acid dilute with water to 25 mL*
or dilute ammonia solution to pH is adjusted with 1 N
a pH acetic acid or 6 N ammonium
between 3.0 and 4.0, hydroxide to a pH between
dilute with water to about 35 3.0 and 4.0,
ml and mix
dilute with water to 40mL,
and mix.
*g, of the substance to be tested, as calculated by the formula: 2.0/(1000L)
SUDIP KUMAR in which L is the Heavy metals limit, as a percentage.

12. IP Method A BP Method A USP Method I 12
Procedure; Procedure; Procedure:
To each of the cylinders As per usp To each of the three tubes
1 standard Solution containing the
2 test solution 1 Standard Preparation
2 Test Preparation
3 Monitor Preparation
add 10 ml of freshly prepared
H2S solution, mix,
2 mL of pH 3.5 Acetate
Buffer,
dilute to 50 ml with water, then add 1.2 mL of
allow to stand for 5 minutes thioacetamide–glycerin base
and view downwards over TS,
white surface;
Dilute with water to 50 mL,
Brown colour wait for 2 minutes, and view
colour produced with the test over white surface
solution is not more intense
than that produced with the colour of Test is not darker
standard solution than Standard
Monitor is equal to or darker
SUDIP KUMAR
than Standard Preparation

13. IP BP USP 13
Method B Method B Method II
Standard solution:* Standard Preparation*
Standard solution:* Test solution: Test Preparation:
Test solution: As per method A
Test (crucible) +H2SO4 ignite at low temp
+ (2ml HNO3 + 5 drops H2SO4)
white fumes
Ignite,(muffle furnace)(500°-600°)to burnt off
carbon +4 ml HCl cover, digest(water- Steam bath
bath) for 15 mins, uncover & evaporate , Moisten
with (1 drop H2SO4 +10 ml hot water)
ammonium hydroxide
digest for 2 min + NH4 solution
dropwise alkaline to litmus
paper
dilute to 25 ml & adjust pH between 3.0 and 4.0
by dilute CH3COOH ,Filter rinse crucible & filter 40 ml
with 10 ml water, combine in 50-ml Nessler
cylinder, dilute to 35 ml and mix
*process is same as method A /method I
SUDIP KUMAR

14. IP BP USP 14
Procedure* Procedure* Procedure*
Method C Method C Method III
Standard solution Standard solution Standard solution
Into a 50-ml Nessler cylinder 10 ml of the solution + add 2
pipette 1.0 ml of lead ml of the test solution
standard solution (20 ppm
Pb),
add 5 ml dilute
sodium hydroxide solution,
dilute with water to 50 ml
and mix
*process is same as method A /method I
SUDIP KUMAR

15. USP Method III 15
Standard solution
Transfer(8 mL H2SO4+10 mL HNO3) clean, dry, 100-mL Kjeldahl flask
add more nitric acid = incremental volume of HNO3 added to Test Preparation
dense, white fumes
cool,add 10 mL of water;
if hydrogen peroxide was used in treating Test Preparation, add volume of 30% hydrogen
peroxide = that used for substance being tested. Boil dense, white fumes.
cool, +5 mL water, mix, boil dense, white fumes
Cool, dilute ,+ 2.0 mL of Standard Lead Solution (20 µg of Pb), and mix.
50-mL colour-comparison tube, rinse to volume is 25 mL, and mix
SUDIP KUMAR

16. IP Method C BP Method C USP Method III 16
Test solution. Test solution. Test solution:
Sample (silica crucible) with 4 ml
50-ml Nessler cylinder of 250 g/l solution of MgSO4 R
place 25 ml test solution or in H2SO4 R. Mix
dissolve specified quantity of
substance white or at most greyish residue
≤ 800 °C
(20 ml H2O + 5 ml of dilute Moisten with dilute H2SO4R.
NaOH)
ignition < 2 h
Dilute to 50 ml
and mix. 5ml HCl + phenolphthalein
+conc NH3
pink colour
+ glacial acetic acid decolorized
+ 0.5 ml Filter & wash Dilute to
20 ml with water R.
SUDIP KUMAR

17. USP Method III 17
Test Preparation: (wet-digestion method)
If solid substance—
weighed quantity 100-mL( Kjeldahl flask)at 45 angle
+ 8 mLH2SO4 and 10 mL of HNO3 to moisten it
boil
until solution darkens.
+2 mL HNO3
+ nitric acid (no darkening occurs) to dense, white fumes.
+ 5 mL water dense, white fumes & reduce volume
Add water examine colour of solution.
If color is yellow, +1 mL of 30 % hydrogen peroxide, dense, white fumes & volume of 2
to 3 mL.
still yellow, repeat 5 mL of water & peroxide treatment.
Cool, dilute cautiously with few mL of water, and rinse into a 50-mL colour-comparison tube,
volume shouldn‘t be exceed 25 mL.
SUDIP KUMAR

18. IP BP USP 18
Procedure. Procedure. Procedure—
similar to that of method A similar to that of method A Similar to that of method I
Method D Method D USP contains only 3 methods
Standard solution. Standard solution. As per
Into a small Nessler cylinder Method A(drying is done)
pipette 10.0 ml of either lead
standard solution (1 ppm Pb)
or lead standard solution (2 Monitor solution:As per
ppm Pb) Method A(drying is done)
Test solution. Test solution
Prepare as directed in the As per method C
individual monograph
and pipette 12 ml into a 0.5 g of magnesium oxide
small Nessler cylinder R1. is used instead of MgSO4
. R in H2SO4 R
SUDIP KUMAR .

19. IP BP USP 19
Procedure. Method D Procedure. Method D
standard solution+ similar to that of method A
2.0 ml of test solution
Method E
+2 ml of acetate buffer pH 3.5, mix,
+1.2 ml of thioacetamide reagent Test solution:
prescribed quantity of test
2 mins substance In 30 ml of water R
or prescribed volume.
view downwards over white surface;
colour produced with test solution is Standard solution.
not more intense than that produced lead standard solution (1 ppm
with standard solution Pb) R to the same volume as the
test solution
Procedure:
Apparatus for limit test of heavy
metals is used
SUDIP KUMAR

20. BP 20
Method F
Test solution:
As per USP Method III
Adjust pH 3.0-4.0 with conc NH3 R1 (dilute may be used) if desired, dilute
to 40 ml and mix.
+ 2 ml of buffer solution pH 3.5 R. Mix and add to 1.2 ml of thioacetamide reagent
Dilute to 50 ml with water R and mix
Standard solution. Prepare at the same time and in the same manner as the test
solution, using the prescribed volume of lead standard solution (10 ppm Pb) R.
Monitor solution Prepare as described for the test solution, adding test substance to
lead standard solution (10 ppm Pb) R prescribed for the preparation of the reference
solution.
Blank solution Prepare as described for the test solution, omitting the substance to be
examined.
SUDIP KUMAR

21. BP 21
Procedure. (Method F )
Examine vertically against white background.
brown colour in the test solution is not more intense than reference solution.
Test is in valid….
if reference solution does not show a brown colour compared blank solution or
if monitor solution is not at least as intense as the reference solution
Method G
(Based on high-pressure digestion method)
Test solution
Place test substance (not more than 0.5 g) in a suitable, clean beaker.
+ 2.7 ml H2SO4 R + 3.3 ml HNO3 R + 2.0 ml of strong H2O2 R using a magnetic stirrer.
Allow to react dry high-pressure-resistant digestion vessel (fluoropolymer or
quartz glass).
SUDIP KUMAR

22. BP (Method G ) 22
Standard solution.
Monitor solution as per method F
Blank solution
Procedure:
it includes use of both high-pressure-resistant digestion vessel and Apparatus for limit test of
heavy metals
Limit Test for Heavy Metals in Herbal Drugs and Fatty Oils
(Ph. Eur. method 2.4.27)
Examine by atomic absorption spectrometry (2.2.23)
SUDIP KUMAR

23. 23
Limit test for Iron
Principle:
Fe2+ React in an ammoniacal solution with thioglycollic acid
Pink to dip reddish purple coloured complex of iron Thioglycollate
Fe(SCH2COOH)2
Ferric ammonium sulphate ,FeNH4(SO4)2:12H2O,as standard
Stability of complex
Air oxidation
Thioglycollate reduce Fe3+ to Fe2+
20% citric acid to remove interference
SUDIP KUMAR

24. 24
Limit test for Iron:
IP BP USP
Iron Standard Solution (20 ppm Fe): Same as IP
Dilute 1 ml 0.1726 % w/v solution of ferric
USP uses ammonium
ammonium sulphate in 0.05 M H2SO4 to 10
volumes with water. Contains iron in ferric
thiocyanate
state
Procedure.
Dissolve test or prepare as directed in
monograph, in Nessler cylinder. + 2 ml 20 %
w/v of iron-free citric acid + 0.1 ml of
thioglycollic acid, mix, make alkaline with iron-
free NH3 solution, dilute to 50 ml,
pink colour is not more intense than that of
2.0 ml of iron standard solution (20 ppm Fe)
in place of solution under examination
SUDIP KUMAR

25. IP Limit test of sulphated ash 25
2.3.18. Sulphated ash
Heat silica or platinum crucible to redness for 10 minutes
Cool(desiccator) weigh it
As per individual monograph, transfer to crucible 1 g of test substance under & weigh the
crucible
Ignite, to charring
Cool, moisten the residue with 1 ml of H2SO4, white fumes no longer evolved
and ignite at 800º ± 25º black particles disappeared.
Ignition without air currents.
+ drops of H2SO4 and heat
Repeat the operation until two successive
weightings do not differ by more than 0.5 mg.
SUDIP KUMAR

26. EP Limit test of sulphated ash 26
Ignite a suitable crucible (silica or platinum )at 600° ± 50° C for 30 min,
allow to cool in a desiccator over silica gel and weigh.
Place in crucible and weigh. Moisten with 1 ml of H2SO4 ,
heat gently at as low temp until the sample is charred.
cool moisten with H2SO4 , heat gently until white fumes are no longer evolved
ignite at 600° ± 50° C until residue is completely incinerated
Ensure that flames are not produced at any time during the procedure.
Allow the crucible to cool over silica gel, weigh it again
If mass of the residue so obtained exceeds the prescribed limit, repeat the moistening with
H2SO4 and ignite to constant mass.
SUDIP KUMAR

27. 27
ICH guideline:
Q4B - ANNEX I
REGULATORY ACCEPTANCE OF ANALYTICAL PROCEDURES AND/OR
ACCEPTANCE CRITERIA (RAAPAC)
ON
RESIDUE ON IGNITION/SULPHATED ASH GENERAL CHAPTER
ANALYTICAL PROCEDURES AND/OR ACCEPTANCE CRITERIA (APAC)
Defination:
―The Residue on Ignition/ Sulphated Ash Test is a method to measure the amount of residual
substance not volatilized from a sample when the sample is ignited in the presence of
sulfuric acid, This test is usually used for determining the content of inorganic impurities in
an organic Substance.‖
Procedure given is similar to that of EP:
SUDIP KUMAR

28. IP Limit test for total ash: 28
Total Ash
Method A. For crude vegetable drugs
 2 to 3 g of air-dried drug in tarred platinum or silica dish and incinerate at a 450ºC
until free from carbon, cool and weigh
 If carbon-free ash is not obtained, wash charred mass with hot water, collect residue on
filter paper, incinerate again until ash is white or nearly white
 evaporate to dryness and ignite .
Calculate the percentage of ash on the dried drug basis
Method B. For all other substances
Heat, cool and weight platinum or silica crucible
weigh accurately about 1 g of test substance, Dry and ignite to constant weight in a muffle
furnace material should not catch fire at any time during procedure. If carbon-free ash
cannot be obtained proceed as directed in method A
 Ignite to constant weight. Calculate the percentage of ash on the dried basis.
SUDIP KUMAR

29. IP Total Ash 29
Acid-insoluble ash
Use Method C unless otherwise directed.
Method C.
Boil ash (Method A or B) with 25 ml of 2M HCl
collect the insoluble matter in a Gooch crucible or on an ashless filter paper,
wash, ignite, cool in a desiccator and weigh.
Calculate % of acid-insoluble ash on the dried drug basis
Method D.
Place ash (Method A or B), or sulphated ash (2.3.18), as directed in the individual
monograph, in crucible, add 15 ml H2O + 10 ml HCl
Cover& boil & cool. Collect the insoluble matter on an ashless filter paper
wash to neutral, ignite to dull redness, cool in an a desiccator and weigh.
Calculate % of acid-insoluble ash on the dried basis.
SUDIP KUMAR

30. IP Total Ash 30
Water-soluble ash
Boil the ash (Method A or B) with 25 ml of water
collect insoluble matter in Gooch crucible or ashless filter paper
wash with hot water, and ignite (450ºC)
 weight of the ash - weight of insoluble matter = weight of water-soluble ash
 Calculate % of water-soluble ash on the dried basis
SUDIP KUMAR

31. USP 31
<643> TOTAL ORGANIC CARBON
Total organic carbon (TOC) is an indirect measure of organic molecules present in
pharmaceutical waters
Two general approaches are used
TOC = TC – IC ( TOC=total organic carbon, TC=total carbon, IC=inorganic carbon )
TOC = POC + NPOC.(POC=purgeable organic carbon , NPOC= nonpurgeable organic carbon)
SUDIP KUMAR

32. IP 32
N,N-Dimethylaniline
Determine by gas chromatography (2.4.13).
Method A
Internal standard solution.
As per individual monograph or dissolve 50 mg of naphthalene in cyclohexane to produce 50
ml. Dilute 5 ml to 100.0 ml with cyclohexane
Test solution (a)
As per individual monograph or take 1.0 g of test substance to a centrifuge tube,
add 5 ml of 1M NaOH, +1.0 ml of cyclohexane,
shake centrifuge Use upper layer
Test solution (b)
As per individual monograph or take 1.0 g of test substance into a centrifuge tube + 5 ml of 1
M NaOH ,dissolve
add 1.0 ml of internal standard solution, shake and centrifuge
Use the upper layer
SUDIP KUMAR

33. IP N,N-Dimethylaniline 33
Reference solution
Take 50.0 mg of N, N-dimethylaniline + 2 ml HCl and 20 ml H2O dissolve & dilute to 50.0 ml
Dilute 5.0 ml to 250.0 ml *
1.0 ml solution into a stoppered centrifuge tube add 5 ml of 1 M NaOH + 1.0 ml of the
internal standard solution
Stopper the tube and shake & Centrifuge if necessary and use the upper layer
Chromatographic system
– a glass column 2 m × 2 mm, packed with silanised diatomaceous support (125 to 180
mesh) impregnated with 3 per cent w/w polymethylphenylsiloxane,
– temperature: column.120º,
inlet port and detector. 150º,
– flow rate 30 ml per minute of nitrogen (carrier gas).
Inject 1 μl of each of the solutions.
SUDIP KUMAR

34. IP N,N-Dimethylaniline 34
Method B
Internal standard solution.
dissolve 75 mg of N, N-diethylaniline in ( 2 ml HCl + 20 ml of water) dilute to 50 ml.
Dilute 2 ml to 100.0 ml with water.
Test solution (a)
Test solution (b) as per Method A
Reference solution.
as per Method A
*Dilute 2 ml to 100.0 ml with water
Chromatographic system
– a glass column 1.5 m × 4 mm, packed with 3 per cent w/ w of cyanoethyl-silicone gum (XE-
60 is suitable) on acid-washed silanised diatomaceous earth (80 to 100 mesh)
– temperature: column. 80º,
inlet port and detector. 150º
– flow rate 30 ml per minute of nitrogen (carrier gas)
SUDIP KUMAR

35. IP N,N-Dimethylaniline 35
Procedure:
Record the chromatograms
and measure the areas for the major peaks
In chromatogram obtained with test solution (b) ratio of the
area of any peak due to N, N-dimethylaniline to area of the
peak due to the internal standard
is not greater than corresponding ratio in chromatogram obtained with internal standard
solution
USP <223>
1 method is given as per Method A of IP
Test solution as per IP Test solution (b)
SUDIP KUMAR

36. BP: 36
Limit Test for Fluorides
(Ph. Eur. method 2.4.5)
Test solution:
With Prescribed qty, 0.1 g of acid-washed sand R and 20 ml of a mixture of equal volumes of
H2SO4 & H2O
Heat the jacket containing tetrachloroethane R maintained at its boiling point (146 °C)
distil, collect distillate in a 100 ml volumetric flask containing 0.3 ml of 0.1 M NaOH and 0.1
ml of phenolphthalein solution R
Maintain a constant volume (20 ml) in tube during distillation and ensure that the distillate
remains alkaline, adding 0.1 M NaOH if necessary.
Dilute the distillate to 100 ml with water R (test solution).
fluoride standard solution
5 ml of (10 ppm F) R instead of test substance
Procedure:
Into two glass-stoppered cylinders introduce 20 ml of test solution and 20 ml of the
standard and 5 ml of aminomethylalizarindiacetic acid reagent R
After 20 min, any blue colour in the test solution (originally red) is not more intense than
SUDIP KUMAR standard
that in the

37. 37
Limit Test for Fluorides
As per BP:
APPARATUS
SUDIP KUMAR

38. BP 38
CADMIUM, COPPER, IRON, LEAD, NICKEL AND ZINC
Examine by atomic absorption spectrometry
Measure the content of cadmium, copper, iron, lead, nickel and zinc by the standard additions
method (2.2.23, Method II), using reference solutions of each heavy metal and the instrumental
parameters described in Table
Cd Ca Fe Ni Pb Zn
Wavelength nm 228.8 324.8 248.3 232 283.5 213.9
Slit width Nm 0.5 0.5 0.2 0.2 0.5 0.5
Lamp current mA 6 7 5 10 5 7
Ingition T ‗c 800 800 800 800 800 800
Atomisation T ‗c 1800 2300 2300
Back ground On Off Off Off Off Off
corrector
Nitrogen flow l/min 3 3 3 3 3 3
SUDIP KUMAR

39. USP 39
Limit test for selenium
Stock Solution— is prepared by Dissolving 40.0 mg of metallic selenium in 100 mL of dilute
nitric acid
Standard Solution: prepared from Stock Solution
Test Solution:
100 to 200 mg, unless directed otherwise in the individual monograph
magnesium oxide is added for combustion and reduces soot formation
Procedure:
Is done in oxygen flask combustion and AAS
the absorbencies are compared of test and standard
SUDIP KUMAR

40. BP 40
Limit Test for Magnesium
(Ph. Eur. method 2.4.6)
magnesium standard solution
1 ml of magnesium standard solution (10 ppm Mg) R and 9 ml of water R
Procedure:
Organic phase - of hydroxyquinoline R in chloroform R
aqueous phase used- butylamine R and triethanolamine R is added
For comparison aqueous phase used-
Any colour in the solution obtained from the substance to be examined is not more intense
than that in the standard.
SUDIP KUMAR

41. BP: Limit test of ARSENIC AND MERCURY 41
Measure the content of arsenic and mercury in comparison with the reference solutions of arsenic or
mercury at a known concentration by direct calibration (2.2.23, Method I) using an automated
continuous-flow hydride vapour generation system.
absorbance of blank solution is automatically subtracted from value obtained with test solution
ARSENIC
Sample solution: 19.0 ml of the test solution or of the blank solution, add 1 ml of a 200 g/l solution of KI
A
Acid reagent Heavy metal-free hydrochloric acid R.
Reducing reagent A 6 g/l solution of sodium tetrahydroborate R in a 5 g/l solution of sodium
hydroxide R.
MERCURY
Sample solution Test solution or blank solution, as prescribed above.
Acid reagent A 515 g/l solution of heavy metal-free hydrochloric acid R.
Reducing reagent A 10 g/l solution of stannous chloride R in dilute heavy metal- free hydrochloric acid
Parameters are given in table
SUDIP KUMAR

42. Parameters are given in table (AAS) 42
As Hg
Wavelength Nm 193.7 253.7
Slit width Nm 0.2 0.5
Lamp current mA 10 4
Acid reagent flow rate ml/min 1.0 1.0
Reducing reagent flow rate ml/min 1.0 1.0
Sample solution flow rate ml/min 7.0 7.0
Absorption cell Quartz Quartz
Background corrector off off
N2 flow rate
SUDIP KUMAR l/min 0.1 0.1

43. 43
References:
Dr T. Narendra sir-- Inorganic Impurities in Drugs
 Q4B - ANNEX I
Indian Pharmacopoeia 2007 Volume 1 page no,76-79
USP32–NF27
British pharmacopoeia Volume 4 2009
Dr T. Narendra sir-- Inorganic Impurities in Drugs
SUDIP KUMAR

44. 44
Incredible India !!!!!
Thank u……….
SUDIP KUMAR