February 22, 2024

Limit Test of Arsenic Pharmaceutical Analysis I Practical, Lab Manual, PDF

Limit Test of Arsenic Pharmaceutical Analysis I Practical, Lab Manual, PDF


Pharmaceutical Analysis I Practical: Limit test for (1) Chloride (2) Sulphate (3) Iron (4) Arsenic Preparation and standardisation of (1) Sodium hydroxide (2) Sulphuric acid (3) Sodium thiosulfate (4) Potassium permanganate (5) Ceric ammonium sulphate Assay (1) Ammonium chloride (2) Ferrous sulphate(3) Copper sulphate (4) Calcium gluconate (5) Hydrogen peroxide (6) Sodium benzoate (7) Sodium Chloride Determination of Normality (1) Conductometric titration of strong acid against a strong base (2) Conductometric titration of strong acid and weak acid against a strong base (3) Potentiometric titration


Aim

To observe limit test for Arsenic

Principle

Limit test for Arsenic is based on the reaction of Arsenic gas with hydrogen ions to form a yellow stain on mercuric chloride paper in presence of reducing agents like potassium iodide. It is also called as Gutzeit test and requires special apparatus.

Arsenic present as arsenic acid in the sample is reduced to arsenious acid by reducing agents like potassium iodide, stannous acid, zinc, hydrochloric acid, etc.. arsenious acid is further reduced to arsine(gas) by hydrogen and reacts with mercuric chloride paper to give yellow stain on mercuric chloride paper will depend upon the quality of arsenic present in the sample.

Limit test for Arsenic Apparatus / Limit test for Arsenic Diagram

Procedure

Label two conical flasks as Standard and Test and follow the procedure

Time needed: 1 hour

Preparation of Standard and Test solution for Arsenic Limit Test

  1. Prepare Standard solution

    Take 1.0 ml of arsenic standard solution and dilute to 50 ml with water.

  2. Add potassium iodide

    add 5 ml of M potassium iodide

  3. Add zinc AsT

    add 10 g of zinc AsT

  4. Assemble the apparatus and immerse the flask

    Immediately assemble the apparatus and immerse the flask in a water bath at a temperature such that a uniform evolution of gas is maintained

  5. Observation of standard solution

    Observe after 40 minutes

  6. Test solution

    Introduce the test solution

  7. Add potassium iodide

    add 5 ml of M potassium iodide

  8. Add zinc AsT

    add 10 g of zinc AsT

  9. Assemble the apparatus and immerse the flask

    Immediately assemble the apparatus and immerse the flask in a water bath at a temperature such that a uniform evolution of gas is maintained

  10. Observation of test solution

    Observe after 40 minutes

Any stain produced on the mercuric chloride paper is not more intense than that of arsenic standard solution


Synopsis Questions

How do you test for arsenic?

Limit test of Arsenic is based on the reaction of arsenic gas with hydrogen ion to form yellow stain on mercuric chloride paper in presence of reducing agents like potassium iodide. It is also called as Gutzeit test and requires special apparatus.

Which apparatus is used for the limit test for arsenic in pharmaceutical chemistry?

.

Which gas is produced in the arsenic limit test?

The reaction of arsenic gas with hydrogen ion in presence of reducing agents like potassium iodide.

Why granulated zinc is used in the limit test of arsenic?

Granulated zinc gives more surface area for the acid to act, so hydrogen is formed faster. It also prolongs the evolution of nascent nitrogen gas

What is the role of zinc in a limit test of arsenic? The function of granulated zinc in limit test for arsenic is?

Arsenic acid is reduced to arsenious acid with help of zinc 

What is the ppm limit for arsenic?

0.01 parts per million (ppm) for Drinking water
The Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit (PEL) of 10 micrograms of arsenic per cubic meter of workplace air (10 µg/m³) for 8-hour shifts and 40 hour work weeks.

What is the concentration of arsenic in the limit test for arsenic?

10 ppm
Preparation of standard arsenic solution: Dissolved 0.330 g of arsenic trioxide in 5ml of 2 M sodium hydroxide and dilute to 250.0 ml with water. Dilute 1 volume of this solution to 100 volumes with water.

Does arsenic show up in blood tests?

Arsenic is not likely to be detected in blood specimens drawn more than 2 days after exposure because it has become integrated into nonvascular tissues

What is the role of Stannous chloride in the limit test for arsenic?

Stannous chloride is used for the complete evolution of arsine.

What is the role of Hydrochloric acid in the limit test for arsenic?

Hydrochloric acid is used to make the solution acidic

The principle of limit test for arsenic is based on?

Limit test for Arsenic is based on the reaction of Arsenic gas with hydrogen ions to form a yellow stain on mercuric chloride paper in presence of reducing agents like potassium iodide. It is also called as Gutzeit test and requires special apparatus

Which stain paper is used in limit test of arsenic?

mercuric chloride paper

Multiple choice questions

  1. The limit test of arsenic is performed to determine the maximum allowable concentration of arsenic in a given sample. Which of the following methods is commonly used for this test?
    a) Flame atomic absorption spectroscopy
    b) Colorimetry
    c) High-performance liquid chromatography
    d) Gravimetric analysis
  2. Which reagent is commonly used in the limit test of arsenic to form a colored complex for detection?
    a) Silver nitrate
    b) Sodium hydroxide
    c) Hydrogen sulfide
    d) Ammonium molybdate
  3. In the limit test of arsenic, a brownish-black precipitate is formed when hydrogen sulfide gas is passed through the acidified sample solution. This precipitate indicates the presence of:
    a) Arsenic
    b) Lead
    c) Copper
    d) Zinc
  4. Which of the following techniques is commonly used to confirm the presence of arsenic in a sample after the limit test?
    a) Mass spectrometry
    b) Infrared spectroscopy
    c) X-ray diffraction
    d) Atomic emission spectroscopy
  5. The limit test of arsenic is based on the principle of:
    a) Precipitation reactions
    b) Acid-base titration
    c) Oxidation-reduction reactions
    d) Complex formation

Answers:

  1. b) Colorimetry
  2. d) Ammonium molybdate
  3. a) Arsenic
  4. a) Mass spectrometry
  5. d) Complex formation

First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

F Y B Pharm Sem-IF Y B Pharm Sem-II
BP101T Human Anatomy and Physiology I TheoryBP201T Human Anatomy and Physiology II – Theory
BP102T Pharmaceutical Analysis I TheoryBP202T Pharmaceutical Organic Chemistry I Theory
BP103T Pharmaceutics I TheoryBP203T Biochemistry – Theory
BP104T Pharmaceutical Inorganic Chemistry TheoryBP204T Pathophysiology – Theory
BP105T Communication skills TheoryBP205T Computer Applications in Pharmacy Theory
BP106RBT Remedial BiologyBP206T Environmental sciences – Theory
BP106RMT Remedial Mathematics TheoryBP207P Human Anatomy and Physiology II Practical
BP107P Human Anatomy and Physiology PracticalBP208P Pharmaceutical Organic Chemistry I Practical
BP108P Pharmaceutical Analysis I PracticalBP209P Biochemistry Practical
BP109P Pharmaceutics I PracticalBP210P Computer Applications in Pharmacy Practical
BP110P Pharmaceutical Inorganic Chemistry Practical
BP111P Communication skills Practical
BP112RBP Remedial Biology Practical

Suggested readings

Recommended readings:



The Gutzeit test is a chemical test used to detect the presence of organic compounds, such as proteins and amino acids, in a sample. It works by adding a strong base, such as sodium hydroxide, to the sample and then measuring the amount of light absorbed at a specific wavelength. The resulting color change is used to determine the presence of specific organic compounds. The apparatus typically used for the Gutzeit test includes a spectrophotometer, cuvettes, and reagents such as sodium hydroxide solution.

The Gutzeit test is a qualitative test used to detect the presence of arsenic in a sample. It is based on the reaction between the sample and a reagent (usually a solution of mercuric nitrate and sodium hydroxide) which forms a yellow precipitate if arsenic is present. The test is a useful tool for determining the presence of arsenic in water, soil, and food samples. However, it should be noted that the Gutzeit test is not very specific and may not differentiate between different forms of arsenic, so further testing may be necessary to confirm the presence of arsenic and determine its exact form.