BS ISO 9198:2020 pdf download – Paper, board and pulp — Determination of water-soluble sulfates This document specifies a method for the determination of water-soluble sulfates in all types of pulp,paper and board. The lower limit of the determination is 20 mg of sulfate ion per kilogram of dry sample. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 186, Paper and board — Sampling to determine average quality ISO 287, Paper and board — Determination of moisture content of a lot — Oven-drying method ISO 638, Paper, board and pulps — Determination of dry matter content — Oven-drying method ISO 7213, Pulps — Sampling for testing 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https://www.iso.org/obp — IEC Electropedia: available at http://www.electropedia.org/ 3.1 water-soluble sulfates in pulp, paper and board, the amount of sulfate ion that is extracted with water at 23 °C and determined under the conditions specified 4 Principle Pieces of the sample are extracted with water at 23 °C in a disintegrator. An aliquot of the resulting suspension is used for determination of the sulfate ion content by ion chromatography. 5 Reagents Use only reagents of recognized analytical quality and only water as specified in 5.1. 5.1 Distilled water or deionized water, of conductivity less than 0,1 mS/m at 25 °C. 5.2 Sulfate stock solution, r(SO 4 –2 ) = 1 000 mg/l. Dry a portion of potassium sulfate (K 2 SO 4 ) at 140 °C. Transfer 181,5 mg ± 2 mg thereof to a 100 ml volumetric flask, dissolve the salt and make up to the mark with water (5.1). material from clogging the syringe. Place the device over the fibres and withdraw the aliquot from the solution above this device. It is essential that the withdrawn aliquot be free from suspended material. Since the operation of the ion chromatograph (6.2) depends on its design, no detailed instructions can be given in this document. Operate the apparatus as instructed by the manufacturer. For calibration,...

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