Rathnagiri Chemicals
Butylated Hydroxy Toluene (2,6 DBPC) TECH GRADE [IS: 9207-1979]

specification and application material safety data sheet

Sr. No.



Method of Text





i )

Purity as C15 H24O, percent by mass, Min




Melting point, Min




Moisture, percent by mass, Max




Sulphated ash, percent by mass, Max





A-1.1 Unless specified otherwise, pure chemicals and distilled water shall be employed in tests.
Note - (Pure chemicals shall mean chemicals that do not contain impurities which affect the results of analysis.

A-2.0 Two methods, namely, infra-red and colorimetric methods have been prescribed. Either method could be used depending upon the availability of apparatus.

A.2.1 Infra-red Method
A-2.1.1 Procedure -Weigh O.600 0 ± 0.0002 g of di-tert-butyl paracresol, technical, into a 10-ml volumetric flask, dissolve the sample in carbon disulphide and fill to the mark with this solvent. Fill a 0.2 mm liquid sample cell with the solution and measure the infrared spectrum of the sample from 11 to 14 using a 1.3 cm rock salt plate in the reference beam, a scan 6peed of 2 min m and a 2 X slit setting- Draw background line from 12-55 to 13-60 m and determine the net absorption at 12.85 m by subtracting the background absorption at this wavelength from the observed absorption. Determine the assay by referring the net absorption value to a. calibration curve (see A-2.1.2).

A-2.1.2 Preparation of Calibration Curve - Weigh 0.48, 0.54- and 0-60 g of a purified sample of di-tert-butyl-para-cresol, technical, into three 10 ml volumetric flasks with an accuracy of ± 0.0002 g. Dissolve the sample in carbon disulphide and dilute to the mark with this solvent. Measure the infra-red spectra of the samples from 11 to 14 m using the same cell and the same instrumental conditions as for the sample. Determine the net absorption at 12-85 m using the procedure described under A-2.1.1, and plot the value against the concentration of di-tert- butyl-para.-cresol technical ( 0-48 and 0-60 g samples represent 80 and 100 percent, respectively ). Draw the best straight line through the three points. If the deviation of any of the points from the line is equivalent to more than 1 percent di-tert-butyl-paracresol, prepare a fourth solution containing from 0.48 to 0.60 g of the reference sample and obtain another calibration point.

A-2.2 Colorimetric Method
A-2.2.1 Reagents
A- Ethanol -
absolute and 72 percent which shall be purified as follows:

To one litre of absolute alcohol add approximately One gram of potassium hydroxide and one gram of potassium permanganate and distil in all glass apparatus discarding first 50 ml of the distillate. Prepare 72 percent alcohol ( u/u ) by diluting the purified absolute alcohol.

A-  2,2’ -bipyridine solution - Dissolve 0.100 g of 2,2’ -bipyridine in 50 ml of purified absolute ethanol.

A- Ferric chloride, solution – 4.5 percent (m/u) solution of ferric chloride (FeCI3, 6H20) in water (0.5 N).

A-2.2.2 Procedure - Weigh 0-100 g di-tert-butyl-para-cresol, technical into a 100~ml volumetric flask, dissolve in absolute ethanol and dilute to the mark with this solvent. Pipette 2.0 ml of the solution into a 25-ml glass-stoppered volumetric flask and dilute to the mark with 72 percent ethanol. Pipette 5.0 ml of the diluted solution into a 25 ml glass-stoppered volumetric flask bound with black tape or metal foil to exclude the light. Add 3.0 ml of absolute ethanol, 2.0 ml of 2,2' -bipyridine solution 2.0 ml of ferric chloride solution. Stopper the Bask immediately and gently swirl the contents. Allow the solution to stand for I hour and measure the absorption at 515 mm using 1.0 cm cells. The measurements are made with reference to a blank prepared at the same time as the sample and containing 5.0 ml or 72 percent ethanol, 3.0 ml of absolute ethanol and 2.0 ml 0f 2,2' -bipyridine solution and 2.0 mi of ferric chloride reagent. Calculate the assay by comparing the absorption obtained with the sample and that obtained with a purified specimen standard reference according to the following equation:

2,6 di-tert-butyl-para-cresol, technical, percent by mass =
(Absorption of sample / Absorption of standard specimen)

x 100

Note - The absorption obtained with a pure sample of di-tert-butyl-Paracresol, chemical should be about 0.47.

Procedure - Determine the melting point according to the method prescribed in IS: 5762-1970 using the thermometer prescribed in A-3.1.1.

A-3.1.1 Thermometer - of mercury-in-glass type with a range from 0 to 150°C graduated at every 0'2 deg, with partial immersion mark at .100 mm, and having a maximum error of ~ 0-2 deg. A thermometer of other suitable range and accuracy may also be used.

The moisture content of the material shall be determined by the procedure prescribed in IS: 2362-1973 taking about 1 g or material weighed to the nearest milligram.


A-5.1 Reagents

A.5.1.1 Concentrated Sulphuric Acid

Dilute Nitric Acid – approximately 0.5 N

A-5.2 Procedure - Weigh accurately about 2 g of the material in a tared crucible. Ignite gently at first, until the material is thoroughly charred. Cool and add one or two drops of nitric acid and heat to remove the nitrous fumes. Now moisten the residue with 1 ml of sulphuric acid and ignite gently till the carbon is completely consumed. Cool the crucible in a desiccator and weigh.

NOTE - Carry out the ignition in a place protected from air currents and use as low temperature as possible to affect the combustion or carbon.

A.5.3 Calculation

Sulphated ash, percent by mass = (M1> / M2) x 100, where

M1 = mass in g, of the residue; and
M2 = mass in g, of the material taken for the test

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