🧪 Chloride in water and wastewater — flow analysis CFA/FIA

Physicochemistry PN-EN ISO 15682

Overview

WHAT THIS STANDARD DESCRIBES. The scope from the PKN catalogue card, in full: "Określono procedury analizy wody i ścieków o zawartości chlorków w zakresie od 1 mg/l do 1000 mg/l. Próbki o większej zawartości chlorków można analizować po rozcieńczeniu. Metodę z detekcją potencjometryczną można stosować do badania próbek mętnych i/lub zabarwionych" [Procedures are specified for the analysis of water and wastewater with a chloride content in the range from 1 mg/l to 1000 mg/l. Samples with a higher chloride content can be analysed after dilution. The method with potentiometric detection can be used for testing turbid and/or coloured samples]. The Polish edition was published on 4 May 2004, has 28 pages and is maintained by KT 121 Water Quality — Chemical Testing — Inorganic Substances, ICS 13.060.50. In the "Implements" field the card gives EN ISO 15682:2001 and ISO 15682:2000, and in the "Replaces" field — PN-EN ISO 15682:2002 in the English-language version. The 2004 edition is therefore the Polish text of the same standard, not a new version of the method.

THREE STANDARDS IN ONE ITEM OF THE REGULATION. The regulation of the Minister of Maritime Economy and Inland Navigation of 12 July 2019 (Journal of Laws 2019 item 1311) lists in Annex No. 12, under item 17 "Chlorki" [chlorides], three methodologies: the volumetric (titrimetric) method according to PN-ISO 9297, ion chromatography according to PN-EN ISO 10304-2, and "analizę przepływową (wstrzykową) (CFA i FIA)" [flow (injection) analysis (CFA and FIA)] according to PN-EN ISO 15682. According to the title on the card, PN-ISO 9297 is "Metoda miareczkowania azotanem srebra w obecności chromianu jako wskaźnika (Metoda Mohra)" [silver nitrate titration with chromate as indicator (Mohr's method)].

HOW LABORATORIES CHOOSE. Measurement on the copy of the accreditation scopes (reading of 23.09.2026; notations BEGINNING with the designation of the standard are counted): PN-ISO 9297 — 238 laboratories and 329 entries; PN-EN ISO 10304-1 — 116 laboratories and 278 entries, of which 107 laboratories and 164 entries for chlorides (chlorides in the test name or in a parameter) — the rest concern other anions; PN-EN ISO 15682 — 3 laboratories and 4 entries; PN-EN ISO 10304-2 — zero, even when this number is searched for anywhere in the field. The numbers say how many laboratories have a given standard in their accreditation scope; they do not say why they chose this one and not another.

THE STANDARD INDICATED FOR ION CHROMATOGRAPHY HAD ALREADY BEEN WITHDRAWN — AND THE ACT HAS A RULE FOR THIS. The card of PN-EN ISO 10304-2:2001 ("Oznaczanie rozpuszczonych anionów za pomocą chromatografii jonowej — Część 2: Oznaczanie bromków, chlorków, azotanów, azotynów, ortofosforanów i siarczanów w ściekach" [Determination of dissolved anions by ion chromatography — Part 2: Determination of bromide, chloride, nitrate, nitrite, orthophosphate and sulphate in wastewater], published on 5 April 2001) has the header "Wycofana i zastąpiona przez PN-EN ISO 10304-1:2009" [Withdrawn and replaced by] and the withdrawal date 29 April 2009. The card of its successor, PN-EN ISO 10304-1:2009, published on the same day, lists in the "Replaces" field both older parts: PN-EN ISO 10304-2:2001 and PN-EN ISO 10304-1:2001. The regulation was promulgated on 15 July 2019 — more than ten years after this standard was withdrawn. The same annex, however, has explanatory note 2: "Jeżeli norma wskazana w załączniku zostanie zastąpiona i wycofana, za normę zalecaną należy uznać nową normę z Polskich Norm" [If a standard indicated in the annex is replaced and withdrawn, the new standard from the Polish Standards shall be regarded as the recommended standard]. For chlorides the condition is met: the standard has been replaced and withdrawn, and the card indicates the successor. For chlorides it is cited by 107 laboratories — in line with this explanatory note.

HOW LABORATORIES WRITE IT. All four entries with this standard have the identical notation "PN-EN ISO 15682:2004" in the database, so the "Laboratories" tab shows the complete set.

WHAT WE DO NOT GIVE. We did not have the text of the standard — PKN makes it available for a fee (28 pages). The card and the title speak of two flow techniques (CFA and FIA), of two modes of detection (photometric and potentiometric) and of the fact that potentiometric detection can be used for turbid and/or coloured samples. We do not give the reaction on which the photometric detection is based, the reagents or the operating conditions.

Method principle

According to the card and the title of the standard: chloride is determined by continuous flow analysis (CFA) or flow injection analysis (FIA), with photometric or potentiometric detection, in the range from 1 mg/l to 1000 mg/l. Samples with a higher chloride content are analysed after dilution, and potentiometric detection can be used for turbid and/or coloured samples. WE DO NOT GIVE the reaction on which the photometric detection is based, the reagents or the flow conditions — we did not have the text of the standard.

Applications

• Water and wastewater — scope of the standard according to the card
• Turbid or coloured samples — the variant with potentiometric detection (card)
• Testing of wastewater for the purposes of Journal of Laws 2019 item 1311 — one of the three standards listed for chlorides (Annex No. 12, item 17)

Key parameters

Standard

Standard number

PN-EN ISO 15682:2004

Title (PL)

Jakość wody — Oznaczanie chlorków metodą analizy przepływowej (CFA i FIA) z detekcją fotometryczną lub potencjometryczną

Title (EN)

Water quality — Determination of chloride by flow analysis (CFA and FIA) and photometric or potentiometric detection

Step-by-step procedure

1. Checking the concentration range

   Range 1–1000 mg/l; samples with a higher chloride content are analysed after dilution (card).

2. Choice of detection

   For turbid and/or coloured samples the card indicates potentiometric detection.

3. Determination

   WE DO NOT GIVE the course of the determination — we did not have the text of the standard.

4. Entry in the report

   State the technique (CFA or FIA) and the mode of detection — the standard contains both variants, and its number alone does not say which one was used.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• We do not describe the hazards associated with the reagents — we do not know their list, because we did not have the text of the standard; the safety data sheets of the reagents used in the laboratory apply

Frequently asked questions