Determination Of Formaldehyde Iso Method.docx

RUSSEL GARMENTS 56/1 S.M. MALEH ROAD, OSMAN TOWER, NARAYANGANJ

Textiles — Determination of formaldehyde Method: ISO 14184-1 Part 1: Free and hydrolized formaldehyde (water extraction method) Scope This Part of ISO 14184 specifies a method for determining the amount of free formaldehyde and formaldehyde extracted partly through hydrolysis by means of a water extraction method. The method can be applied to the testing of textile samples in any form. The procedure is intended for use in the range of free & hydrolysed formaldehyde on the fabric between 20 mg/kg and 3500 mg/kg when determined by this method. The lower limit is 20 mg/kg. Below this limit the result is reported as ‘not detectable’. Principle Formaldehyde is extracted from a textile sample with water at 40°C. The amount of formaldehyde is then determined calorimetrically. Reagents All reagents shall be analytical reagent quality. 1. Distilled water or grade 3 water complying with ISO 3696. 2. Acetylacetone reagent (Nash reagent). Dissolve 150 g of ammonium acetate in about 800 ml of water; add 3 ml of glacial acetic acid and 2 ml of acetylacetone, transfer into a 1000 ml volumetric flask and make up to the mark with water. Store in a brown bottle. NOTE: The reagent darkens in colour slightly on standing over the first 12 h. For this reason the reagent should be held 12 h before use. Otherwise, the reagent is useable over a considerable period of time, at least 6 weeks. Since the sensitivity may change slightly over a long period of time, it is good practice to run a calibration curve weekly to correct for slight changes in the standard curve. 3. Formaldehyde solution, approximately 37% (W/V or W/W). Apparatus: 1. Stoppered volumetric flasks, 50 ml, 250 ml, 500 ml and 1000 ml. 2. Flask, 250 ml, with stopper. 3. Pipettes, 1 ml, 5 ml, 10 ml and 25 ml volumetric and 5 ml graduated. 4. Burettes, 10 ml and 50 ml. 5. Photoelectric colorimeter or spectrometer, (wavelength, 412 nm). 6. Test tubes / Vial, colorimeter tubes or spectrometer tubes. 7. Shaking Water bath, at (40 ± 2) °C. 8. Filters, made from heat resistant glass having a pore size between 40 mm and 100 mm (pore symbol P100 in accordance with ISO 4793). 9. Balance, accurate to 0. 2 mg.

RUSSEL GARMENTS 56/1 S.M. MALEH ROAD, OSMAN TOWER, NARAYANGANJ

Sample Preparation: 1. Cut two specimens approximately 1g of pieces. If the formaldehyde content is low, increase the test specimen weight to 2.5 g. 2. Put the weighed pieces into 250ml flask with stopper and add 100ml of water. 3. Stopper tightly and place in a water bath at 40 ± 2°C for 60 ± 5 min with shaking at least every 5 min. 4. Filter the solution into another flask through a filter. Important Notes: • Do not condition the test specimen before test • Storage the test sp. in a polyethylene bag and wrapped in Al foil. Test Procedure: Prepare four Test Tubes A to D as follows:

1. Tube A (SV): 5ml of the filtered test specimen solution + 5ml NR. 2. Tube B: 5ml of the standard formaldehyde solutions + 5ml of Nash reagent. 3. Tube C (MB): 5ml of Nash reagent + 5ml of water (Blank). 4. Tube D (SB): 5ml of filtered test specimen solution + 5ml of water (Blank). 5 ml filtered test specimen soln + 5ml NR

5 ml std HCHO soln + 5ml NR

5ml NR + 5ml DW

5 ml filtered test sp soln + 5ml DW

5. Keep the Tubes A & B in a water bath at 40 + 2C for 30 + 5min and then at ambient temperature for 30±5min. 6. Measure the absorbance using a spectrometer in a 10mm absorption cell at a wavelength of 412mm against water.

RUSSEL GARMENTS 56/1 S.M. MALEH ROAD, OSMAN TOWER, NARAYANGANJ

Calculations: We know that, Formaldehyde content (F) in ppm = {(SV – SB) – MB} x 100 / SW. Where, SV = sample value in ppm. SB = sample Blank in ppm. MB = Method Blank in ppm. SW = sample weight in gm. Given from data, SV = 0.4967 ppm SB = 0.0357 ppm MB= 0.1026 ppm SW = 1.0 g F = {(0.4967- 0.0357) – 0.1026} x 100 / 1.0. = 36 ppm. We know that, Corrected Absorbance (A) = = (As – Ab) – MB. Where, As= Sample absorbance Ab= Blank absorbance MB = Method blank Given from data, As= 0.08 abs Ab= 0.0045 abs MB = 0.015 abs A = (0.08 – 0.0045) – 0.015. = 0.07 abs.

RUSSEL GARMENTS 56/1 S.M. MALEH ROAD, OSMAN TOWER, NARAYANGANJ

Calculate the arithmetic mean of the two values. If the result is less than 20 mg/kg report as ‘not-detectable’.

Test report: The test report shall include the following information: a) The number and year of publication of this International Standard, i.e. ISO 14184-1:1998; b) The date the sample was received the means in which it was stored prior to test and the date tested; c) Description of the sample tested and how packaged; d) The mass of the test specimens and, if required, the correction coefficient for the mass; e) The range of the calibration graph; f) The amount of formaldehyde extracted from the sample. g) Any deviation, by agreement or otherwise, from the procedure specified.