Limit Test for Arsenic in Pharmaceutical Analysis

Method A:

The device comprises of a100 ml funnel shaped carafe shut with a ground-glass plug through which passes a glass tube around 200 mm long and of inner distance across 5 mm. The lower some portion of the tube is attracted to an inner distance across of 1.0 mm, and 15 mm from its tip is a parallel opening 2 mm to 3 mm in measurement. At the point when the tube is in position in the plug, the horizontal opening ought to be no less than 3 mm beneath the lower surface of the plug. The upper end of the tube has a splendidly level, ground surface at right edges to the pivot of the tube.

A second glass container of the same interior breadth and 30 mm long, with a comparable level ground surface, is put in contact with the initially, and is held in position by two winding springs. Into the lower tube embed 50 mg to 60 mg of lead acetic acid derivation cotton R, approximately stuffed, or a little fitting of cotton and a moved bit of lead acetic acid derivation paper R measuring 50 mg to 60 mg. Between the level surfaces of the tubes put a plate or a little square of mercuric bromide paper R sufficiently extensive to cover the hole of the tube (15 mm × 15 mm). In the funnel shaped flagon break down the recommended amount of the substance to be inspected in 25 ml of water R, or on account of an answer modify the endorsed volume to 25 ml with water R. Include 15 ml of hydrochloric corrosive R, 0.1 ml of stannous chloride arrangement R and 5 ml of potassium iodide arrangement R, permit to remain for 15 min and present 5 g of initiated zinc R.

Collect the two sections of the mechanical assembly quickly and inundate the cup in a shower of water at a temperature such that a uniform development of gas is kept up. Set up a standard in the same way, utilizing 1 ml of arsenic standard arrangement (1 ppm As) R, weakened to 25 ml with water R. After at the very least 2 h the stain created on the mercuric bromide paper in the test is not more extreme than that in the standard.

Method B:

Present the endorsed amount of the substance to be analyzed into a test-tube containing 4 ml of hydrochloric corrosive R and around 5 mg of potassium iodide R and include 3 ml of hypo phosphorous reagent R .Heat the blend on a water-shower for 15 min, shaking infrequently. Set up a standard in the same way, utilizing 0.5 ml of arsenic standard in limit test for arsenic arrangement (10 ppm As) R.

Subsequent to warming on the water-shower, any shading in the test arrangement is not more serious than that in the standard