ISO 6588-1-2020 pdf download

ISO 6588-1-2020 pdf download.Paper, board and pulps 一 Determination of pH of aqueous extracts一 Part 1: Cold extraction. 5 Reagents 5.1 Water. distilled or delonñed water shall be used throughout the tesi the conductivity of the waler shall not exceed 0.1 mS/rn, after boiling for 1 h and cooling In an acid-free atmosphere (e.g tree or co2, SO2, 14,5) to a temperature between 20°C and 25 C The pH of the water should be In the range of 6.8 to 7,3. Instructions for the determination olcondUa-tiVdy are specified in 15(1 3696, 5.2 Standard buffer solutions, with known pH-values of about 4, 7 and 9 Such buffer solutions are commercially avaibble. Some examples of suitable buffer solutions are given, and their preparation is described. in Annex A. 3.3 PotassIum chloride solution. 1M. Dissobre 7,4 g of K(I, analytical giade, Into 104) ml or freshly boiled, distilled waler. Prepare a fresh solution cvely week 6 Apparatus and equipment Uc (hr following, in addilion to ordinary laboratory apparatus and equipment. 6.1 Glassware of chrmicafly resutant glass, flasb with ground-glasa joints, stoppers, beakers and trifled glass hlter All glassware shall be cleaned with an acid cleaning solution, without the ie of soap or dc±tei’gent. and they shall be cai’rlul)y rinsed with watrt (11) and allowed to dry beluru uw 6.2 pH.rneter, lined with glass and calomel electrodes or with a combined electrode, capable olbeing read to at least 0,05 p11-unit. 7 SamplIng and preparatIon of sample 7.1 Sampling The sampling procedure to be followed depends on the particular circumstances in each case. lithe analysis u being made to evaluate a lot or a consignment of pulp, paper or board, the sample shall be taken in accordance with ISO 7213 or 150 186. as relevant. If the analysis is made on another type ol sampi., report the origin of the sample and, if possible, the sampling procedure, and ensure that the specimen taken in 7.1 ix representative of the sample received. Wear clean protective gloves when handling the sample. NOTE Some gloves are powdered to prevent them from stxkrng to one anoihet and this powder can cause contamination of the sample. 7.2 PreparatIon of sample Do not touch the sample with bare hands and ensure that it has been placed only on clean surfaces. Cut the sample with a knife or cutter, or tear it. Into pieces approximately 1 cm In size, Split samples of...