ISO 14402 pdf download

ISO 14402 pdf download.Water quality — Determination of phenol index by flow analysis (FIA and CFA) 1 Scope This International Standard specifies two methods for the determination of the phenol index in waters of different origin (such as ground waters, surface waters, seep waters, and waste waters) in mass concentrations of 0,01 mg/l to 1 mg/l (in the undiluted sample). In particular cases, the range of application may be adapted by varying the operating conditions. Clause 3 describes the determination of phenol index (without distillation) after extraction, and in clause 4 the determination of phenol index (without extraction) after distillation is given. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 3696:1 987, Water for analytical laboratory use — Specification and test methods. ISO 5667-3:1 994, Water quality — Sampling — Part 3: Guidance on sample handling and preservation. ISO 6439:1 990, Water quality — Determination of phenol index — 4-Aminoantipyrine spectrometric methods after distillation. 3 Determination of phenol index (without distillation) after extraction 3.1 Principle The sample is fed into a continuously flowing carrier stream and mixed with also continuously flowing solutions of 4- aminoantipyrine and potassium peroxodisulfate. Phenolic compounds in the sample are oxidized by potassium peroxodisulfate, and the resulting quinones react with 4-aminoantipyrine, forming coloured condensation products. These are extracted in a flow extraction unit from the aqueous phase into chloroform. The chloroform phase is separated by a suitable phase separator (e.g. a hydrophobic semipermeable membrane), and the absorbance of the organic phase is measured spectrometrically in a flow spectrometer at 470 nm to 475 nm. More information on this analytical technique is given in the references [6 to 9]. It is absolutely essential that the test described in this International Standard be carried out by suitably qualified staff. 3.2 Interferences 3.2.1 Chemical interferences Under the prevailing reaction conditions, aromatic amines will also form condensation products with 4-aminoanti- pyrine, leading to positive bias.Interferences can occur when...