CEN/TC 230/WG 1 - Physical and biochemical methods

This document specifies a method for the determination of the dissolved fraction of selected perfluoroalkyl and polyfluoroalkyl substances (PFAS) in non-filtrated drinking water using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The applicability of the method to other types of water like fresh waters (e.g. ground water, surface water) or treated wastewater can be validated separately for each individual case.
For each target compound both, eventually occurring branched isomers and the respective non-branched isomer, are quantified together. The selected set of substances determined by this method is representative for a wide variety of PFAS. This method has been validated for the analytes specified in Table 1. The list given in this table can be modified depending on the purpose and focus of the method. The lower application range of this method can vary depending on the sensitivity of the equipment used and the matrix of the samples. For many substances to which this document applies a limit of quantification (LOQ) of 1 ng/l can be achieved. Using high volume direct injection as described in part A or SPE as described in part B of the method allows lower LOQs. Analytical limitations can occur with short-chain PFAS or PFAS with more than ten carbon atoms in the carbon chain. Actual LOQs can depend on the blank values realized by individual laboratories as well.
NOTE   This document enables the analysis of those 20 PFAS which are listed in point 3 of Part B of Annex III of the EU Drinking Water Directive, EU 2020/2184 [4], for the surveillance of the parametric limit value of 0,10 µg/l for the sum of PFAS.
Furthermore, alternatives and substitutes for these PFAS substances can be analysed using this document as well.
Table 1 - Analytes for which a determination was validated in accordance with this method

ISO 20595:2018 specifies a method for the determination of selected volatile organic compounds in water (see Table 1). This comprises among others volatile halogenated hydrocarbons as well as gasoline components (BTXE, TAME, MTBE and ETBE).
The method is applicable to the determination of volatile organic compounds (see Table 1) in drinking water, groundwater, surface water and treated waste water in mass concentrations >0,1 µg/l. The lower application range depends on the individual compound, the amount of the blank value and the matrix.

This document specifies a method for the determination of certain cyclic volatile methylsiloxanes (cVMS) in environmental water samples with low density polyethylene (LDPE) as a preservative and subsequent liquid-liquid extraction with hexane containing 13C-labeled cVMS as internal standards. The extract is then analysed by gas chromatography-mass spectrometry (GC-MS).
NOTE       Using the 13C-labeled, chemically identical substances as internal standards with the same properties as the corresponding analytes, minimizes possible substance-specific discrimination in calibrations. Since these substances are least soluble in water, they are introduced via the extraction solvent hexane into the system.

This document specifies a method for the determination of the dissolved fraction of selected active pharmaceutical ingredients and transformation products, as well as other organic substances (see Table 1) in drinking water, ground water, surface water and treated waste water.
The lower application range of this method can vary depending on the sensitivity of the equipment used and the matrix of the sample. For most compounds to which this document applies, the range is ≥ 0,025 µg/l for drinking water, ground water and surface water, and ≥ 0,050 µg/l for treated waste water.
The method can be used to determine further organic substances or in other types of water (e.g. process water) provided that accuracy has been tested and verified for each case, and that storage conditions of both samples and reference solutions have been validated. Table 1 shows the substances for which a determination was tested in accordance with the method. Table E.1 provides examples of the determination of other organic substances.

This document specifies the following semi-quantitative methods for the assessment of transparency of waters:
a)    measurement of visual range using the transparency testing tube (applicable to transparent and slightly cloudy water),  see Clause 4;
b)    measurement of visual range in the upper water layers using the transparency testing disc (especially applicable to surface, bathing water, waste water and often used in marine monitoring), see 5.1;
c)    measurement of visibility by divers in a destined depth, see 5.2.
NOTE       The quantitative methods using optical turbidimeters or nephelometers are described in ISO 7027-1.

This document specifies continuous flow analysis  (CFA) methods for the determination of orthophosphate in the mass concentration range from 0,01 mg/l to 1,00 mg/l P, and total phosphorus in the mass concentration range from 0,10 mg/l to 10,0 mg/l P. The method includes the digestion of organic phosphorus compounds and the hydrolysis of inorganic polyphosphate compounds, performed either manually, as described in ISO 6878 and in References [4], [5] and [7], or with an integrated ultraviolet (UV) digestion and hydrolysis unit.
This document is applicable to various types of water, such as ground, drinking, surface, leachate and waste water. The range of application can be changed by varying the operating conditions.
This method is also applicable to the analysis of seawater, but with changes in sensitivity by adapting the carrier and calibration solutions to the salinity of the samples.
It is also applicable to analysis using 10 mm to 50 mm cuvettes depending on the desired range. For extreme sensitivity, 250 mm and 500 mm long way capillary flow cells (LCFCs) can be used. However, the method is not validated for these two uses. Changes in sensitivity and calibration solutions could be required.
Annex A provides examples of a CFA system. Annex B gives performance data from interlaboratory trials. Annex C gives information of determining orthophosphate-P and total-P by CFA and tin(II) chloride reduction.

ISO 7393-2:2017 specifies a method for the determination of free chlorine and total chlorine in water, readily applicable to lab- and field-testing. It is based on measurement of the absorption, the red DPD colour complex in a photometer or the colour intensity by visual comparison of the colour with a scale of standards that is regularly calibrated.
This method is appropriate for drinking water and other waters, where additional halogens like bromine, iodine and other oxidizing agents are present in almost negligible amounts. Seawater and waters containing bromides and iodides comprise a group for which special procedures are to be carried out.
This method is in practice applicable to concentrations, in terms of chlorine (Cl2), from, for example, 0,000 4 mmol/l to 0,07 mmol/l (e.g. 0,03 mg/l to 5 mg/l) total chlorine. For higher concentrations, the test portion is diluted.
Commonly, the method is applied as a field method with mobile photometers and commercially available ready-for-use reagents (liquid reagents, powders and tablets). It is essential that those reagents comply with minimum requirements and contain the essential reagents and a buffer system suitable to adjust the measurement solution to a pH range of typically 6,2 to 6,5. If there is doubt that water samples have uncommon pH values and/or buffer capacities, the user has to check and, if necessary, to adjust the sample pH to the required range. The pH of the sample is within the range of pH 4 and 8. Adjust, if necessary, with sodium hydroxide solution or sulfuric acid before the test.
A procedure for the differentiation of combined chlorine of the monochloramine type, combined chlorine of the dichloramine type and combined chlorine in the form of nitrogen trichloride is presented in Annex A. In Annex C, a procedure is presented for the determination of free and total chlorine in drinking and other low polluted waters, for disposable planar reagent-filled cuvettes using a mesofluidic channel pump/colorimeter.

ISO 7027-1:2016 specifies two quantitative methods using optical turbidimeters or nephelometers for the determination of turbidity of water:
a)    nephelometry, procedure for measurement of diffuse radiation, applicable to water of low turbidity (for example drinking water);
b)    turbidimetry, procedure for measurement of the attenuation of a radiant flux, more applicable to highly turbid waters (for example waste waters or other cloudy waters).
Turbidities measured according to the first method are presented as nephelometric turbidity units (NTU). The results typically range between <0,05 NTU and 400 NTU. Depending on the instrument design, it can also be applicable to waters of higher turbidity. There is numerical equivalence of the units NTU and formazin nephelometric unit (FNU).
Turbidity measured by the second method is expressed in formazin attenuation units (FAU), results typically range between 40 FAU and 4 000 FAU.

ISO 14403-1:2012 specifies methods for the determination of cyanide in various types of water (such as ground, drinking, surface, leachate, and waste water) with cyanide concentrations from 2 µg/l to 500 µg/l expressed as cyanide ions in the undiluted sample. The range of application can be changed by varying the operation conditions, e.g. by diluting the original sample or using a different injection volume.
In ISO 14403-1:2012, a suitable mass concentration range from 20 µg/l to 200 µg/l is described.
Seawater can be analysed with possible changes in sensitivity and adaptation of the reagent and calibration solutions to the salinity of the samples.

ISO 14403-2:2012 specifies methods for the determination of cyanide in various types of water (such as ground, drinking, surface, leachate, and waste water) with cyanide concentrations usually from 2 µg/l to 500 µg/l expressed as cyanide ions in the undiluted sample. The range of application can be changed by varying the operation conditions, e.g. by diluting the original sample or changing the pathlength of the flow cell.
In this method, a suitable mass concentration range from10 µg/l to 100 µg/l is described.
Seawater can be analysed with possible changes in sensitivity and adaptation of the reagent and calibration solutions to the salinity of the samples.

TC - Insertion of Annex ZA  A-deviation
2007-01-18 - A-deviation text received
2006-11-28 - Pending awaiting text of A-deviation from TC 230 (see email dated 2006-07-06)

ISO 23631:2006 specifies a method for the determination of dalapon, trichloroacetic acid (TCA) and selected haloacetic acids in ground water and drinking water by gas chromatography (GC-ECD and/or GC-MS detection) after liquid-liquid-extraction and derivatization using diazomethane. Depending on the matrix, the method is applicable to a concentration range from 0,5 to 10 micrograms per litre. The validated reporting limit of TCA and dalapon is about 0,05 micrograms per litre. Detection by electron-capture detector (ECD) in general leads to lower detection limits. Detection by mass spectrometry (MS) allows analyte identification.

ISO 17353:2004 specifies a method for the identification and quantification of monobutyltin, dibutyltin, tributyltin, tetrabutyltin, monooctyltin, dioctyltin, triphenyltin, tricyclohexyltin compounds and/or cations in drinking water, surface water and wastewater containing not more than 2 g/l of suspended material. The working range is 10 ng/l to 1 000 ng/l. The respective anions are not determined.
This method can also be applicable to other compounds such as monomethyltin, dimethyltin, monophenyltin and diphenyltin compounds and/or cations. ISO 17353:2004 is also applicable to marine water.

ISO 15681-1:2003 specifies flow injection analysis (FIA) methods for the determination of orthophosphate in the mass concentration range from 0,01 mg/l to 1,0 mg/l (P), and total phosphorus by manual digestion in accordance with ISO 6878 for the mass concentration range from 0,1 mg/l to 10 mg/l (P). The range of application can be changed by varying the operating conditions.
ISO 15681-1:2003 is applicable to various types of water (such as ground, drinking, surface, leachate and waste waters).
This method is also applicable to the analysis of seawater, but with changes in sensitivity, by adaptation of the carrier and calibration solutions to the salinity of the samples.

This International Standard specifies two methods, i.e. flow injection analysis (FIA) and continuous flow analysis (CFA), for the determination of soluble silicate ions in various types of water (such as ground, drinking, surface, leachate and waste water). Both methods are applicable to the determination of a mass concentration of silicate (SiO 2) ranging from 0,2 mg/l to 20 mg/l (with working ranges 0,2 mg/l to 2,0 mg/l and 2,0 mg/l to 20 mg/l). Other mass concentration ranges are applicable, provided they cover exactly one decade of concentration units (e.g. 0,02 mg/l to 0,2 mg/l in SiO2).
These methods can be made applicable to seawater by changing the sensitivity and by adapting the reagent and calibration solutions to the salinity of the samples.

ISO 17993:2002 specifies a method using high performance liquid chromatography (HPLC) with fluorescence detection for the determination of 15 selected polycyclic aromatic hydrocarbons (PAH) [naphthalene, acenaphthene, phenanthrene, fluoranthene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, fluorene, anthracene, pyrene, chrysene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene, benzo(ghi)perylene] in drinking and ground water in mass concentrations greater than 0,005 microgram/litre (for each single compound) and surface waters in mass concentrations above 0,01 microgram/litre.
This method is, with some modification, also suitable for the analysis of waste water. This method may be applicable to other PAH, provided the method is validated for each case.

This International Standard specifies a method for the determination of the following six water-soluble organic complexing agents in the concentration range from 0,5 micrograms/litre to 200 micrograms/litre:
EDTA (ethylenedinitrilotetraacetic acid);NTA (nitrilotriacetic acid);DTPA (diethylenetrinitrilopentaacetic acid);MGDA (methylglycinediacetic acid);ß-ADA (ß-alaninediacetic acid);1,3-PDTA (1,3-propylenedinitrilotetraacetic acid).
The method is applicable to drinking, ground, surface and waste water.

ISO 15680:2003 specifies a general method for the determination of volatile organic compounds (VOCs) in water by purge-and-trap isolation and gas chromatography (GC). Annexes A, B and C provide examples of analytes that can be determined using ISO 15680:2003. They range from difluorodichloromethane (R-12) up to trichlorobenzene, including all non-polar organic compounds of intermediate volatility.
Detection is preferably carried out by mass spectrometry in the electron impact mode (EI), but other detectors may be applied as well.
The limit of detection largely depends on the detector in use and the operational parameters. Typically detection limits as low as 10 ng/l can be achieved. The working range typically is up to 100 micrograms per litre.
ISO 15680:2003 is applicable to drinking water, ground water, surface water, seawater and to (diluted) waste water.

ISO 15586:2003 includes principles and procedures for the determination of trace levels of: Ag, Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn in surface water, ground water, drinking water, wastewater and sediments, using atomic absorption spectrometry with electrothermal atomization in a graphite furnace. The method is applicable to the determination of low concentrations of elements.
The detection limit of the method for each element depends on the sample matrix as well as of the instrument, the type of atomizer and the use of chemical modifiers. For water samples with a simple matrix (i.e. low concentration of dissolved solids and particles), the method detection limits will be close to instrument detection limits. The minimum acceptable detection limit values for a 20-microlitre sample volume are specified.

This European Standard specifies a method for the determination of epichlorohydrin in drinking water and water used for drinking water processing. According to the given procedure, the limit of determination in routine analysis is about 0,5 µg/l  1) . The limit of determination may be lowered to monitor 0,1 µg/l.
1) This value will be checked in an interlaboratory trial.

This part of ISO 15587 specifies a method for extracting trace elements from a water sample using aqua regia as a digestion agent. The method is applicable to all types of waters with a suspended solids mass concentration of less than 20 g/l and a mass concentration of total organic carbon (TOC) expressed as carbon of less than 5 g/l.
The aqua regia digestion method is empirical and it might not release elements completely. However, for most environmental applications, the result is fit for purpose.
Aqua regia digestion is suitable for the release of: Ag, Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, Sr, Tl, V, Zn. It is not suitable for the digestion of refractory compounds such as SiO 2, TiO2 and Al2O3. The presence of chloride in the digestion solution may limit the application of analytical techniques.
The method is generic and may be implemented using a wide variety of equipment provided the digestion composition is unchanged, the digestion temperature is known, and the digestion duration is in accordance with this temperature.

This part of ISO 15587 specifies a method for extracting trace elements from a water sample using nitric acid as a digestion agent. The method is applicable to all types of waters with a suspended solids concentration of less than 20 g/l and a total organic carbon (TOC) concentration expressed as carbon of less than 5 g/l.
The nitric acid digestion method is empirical and it might not necessarily release elements completely. However, for most environmental applications the result is fit for purpose.
Nitric acid digestion is suitable for the release of: Al*, As, B, Ba*, Be*, Ca, Cd, Co, Cr*, Cu, Fe*, Hg, K, Mg*, Mn, Mo, Na, Ni, P, Pb, Se, Sr, Tl, V*, Zn (asterisk indicates a possible lower recovery compared to the aqua regia digestion method specified in ISO 15587-1). It is suitable for the release of Ag only if the sample is stabilized immediately after digestion. Nitric acid digestion is not suitable for Sb, Sn and for the digestion of refractory compounds such as SiO 2, TiO2 and Al2O3.
The method is generic and may be implemented using a wide variety of equipment provided the digestion composition is unchanged, the digestion temperature is known, and the digestion duration is in accordance with this temperature.

The procedure is outlined for the analysis of chloride, in the range of 1 to 1000 mg/l, in various water samples (e.g. ground-, drinking-, surface- and waste water, and leachates). On an individual basis the range of the analysis can be changed.

Migrated from Progress Sheet (TC Comment) (2000-07-10): TC N 301 (work programme 980408): TC230 Res. by corr. for // voting on later ++ kISO/DIS 15061, ISO lead (TA/980429) ++ new td 49 in BP (bli 991125)

Migrated from Progress Sheet (TC Comment) (2000-07-10): To be renumbered part 2 at DIS stage (Res BT 79/1998) (CC/981106) ++ Mr. Lingner has just confirmed that Part 2 & Part 3 have been deleted from the I ++ SO work programme and that consequently Part 4 has to be renumbered Part 2. Ho- ++ wever since the // DIS/ENQ has just been initiated, the change will be done at ++ FV/FDIS stage (TA/990319)

Migrated from Progress Sheet (TC Comment) (2000-07-10): CEN/TC 230N285: V.A ISO lead + see file CEN/TC 230 CORR (TA/970918) ++ SPPJ_09_Y_199804 ++ 980120: ISO/DIS 10695-1 was sent out in June 1997 in ISO for ENQ. ISO agrees to ++ wait until we carry out our PQ because their texts for FDIS will not become ++ available before May/June 1998 (TA/980120)

Specifies a procedure for water. It is applicable for the measurement of concentrations, in terms of chlorine, from 0,01 to 0,21 mmol/l. The interfering substances are given. In annex B a procedure for direct titration is specified. It is usually applied to chlorine concentrations above 7 mol/l in treated drinking water.

Specifies a procedure for water. Sea water and waters containing bromides and iodides comprise a group for which special procedures are required. The procedure is applicable to concentrations, in terms of chlorine, from 0,000 4 to 0,07 mmol/l total chlorine and at higher concentrations by dilution of samples. Several compounds influencing the procedure are noted.

Describes a flame atomic absorption spectrometric method and a graphite furnace atomic absorption spectrometric method for the determination of aluminium in water. The flame AAS method is applicable to mass concentrations from 5 mg/l to 100 mg/l and the graphite furnace AAS method is applicable to mass concentrations from 10  g/l to 100  g/l in water and waste water.

The procedure is intended for the analysis of raw and drinking waters and can be used for waters having a calcium content of up to 50 mg/l and a magnesium content of up to 5 mg/l. For samples containing higher concentrations of calcium or magnesium a smaller volume of the sample must be taken for the analysis.

This dcoument specifies a method for the determination of fluoro-, chloro-, bromo- and iodo-organic compounds (AOF, AOCl, AOBr, AOI). Due to the high solubility of AgF in water the scope of ISO 9562 is restricted to Cl-, Br- and I-organic compounds (AOX, calculated as chlorine) because of the applied argentometric detection. The PN follows the proven AOX ISO 9562 method: adsorption of organohalogen
compounds on activated carbon, oxidative combustion at 1000 °C with following alterations: constant water feed during combustion (hydropyrolysis), absorption of combustion gases in water, halide specific detection using ionchromatography. The method is applicable for the determination of
2 µg/l AOF, expressed as F
10 µg/l AOCl, expressed as Cl
1 µg/l AOBr, expressed as Br
1 µg/l AOI, expressed as I.
Samples for determination of AOF are treated differently than samples for the determination of AOCl,
AOBr and AOI.
- Samples for determination of AOF are not acidified. The adsorption takes place under unchanged pH
conditions. Washing is also performed with a neutral washing solution.
- Samples for the determination of AOCl, AOBr and AOI are adjusted to a pH value 2 with nitric acid,
the adsorption and washing take place in a nitric acid environment.

This document specifies a method for the photometric determination of dissolved chromium(VI) using
manual, e.g., hand photometry, or automated static, e.g., discrete analyser system, or automated
dynamic techniques, e.g., flow injection analysis (FIA), continuous flow analysis (CFA), or ion
chromatography with post-column derivatization (IC-PCR). Typical areas of application for the static
techniques as well as FIA and CFA are samples with Cr(VI) concentrations 2 �g/l in raw water,
drinking water, surface water, aqueous eluates, cooling water and treated wastewater, provided that
the Matrix does not contain any reducing substances. When using cuvettes with large optical path
lengths, e.g. >100 mm, the range of application can be extended to concentrations 2 �g/l Cr(VI). When
using coupled techniques (e.g. IC-PCR), Cr(VI) concentrations 0,02 �g/l can be determined.
The NP is based on DIN 38405-52:2020-11.

This document specifies a method for the determination of 5 oestrogens, in whole water samples listed in Table 1. The method uses solid-phase extraction (SPE-disks and/or cartridges) followed by liquid or gas chromatography-mass spectrometry (tandem mass spectrometry and/or High resolution mass spectrometry). It is applicable to the analysis of selected estrogens in surface water containing suspended particulate matter (SPM) up to 50 mg/l , DOC content up to 7 mg/l (whole water samples), drinking water and groundwater.

This International Standard describes CFA and FIA methods for the analysis of orthophosphate in the range of 0,01 mg/l to 1,0 mg/l (P) and total phosphorus (by manual digestion or with an integrated UV digestion) in the range of 0,1 mg/l to10 mg/l (P). The range of application may be changed by varying the operating conditions. This method is applicable to the analysis of seawater, but with changes in sensitivity and adaptation of the reagent and calibration solutions to the salinity of samples.

ISO 15681-2:2003 specifies CFA methods for the determination of orthophosphate in the mass concentration range from 0,01 mg/l to 1,00 mg/l P, and total phosphorus in the mass concentration range from 0,10 mg/l to 10,0 mg/l P. The method includes the digestion of organic phosphorus compounds and the hydrolysis of inorganic polyphosphate compounds, performed either manually as described in ISO 6878 or with an integrated UV digestion and hydrolysis unit.
ISO 15681-2:2003 is applicable to various types of water (such as ground, drinking, surface, leachate and waste water). The range of application may be changed by varying the operating conditions.
This method is also applicable to the analysis of seawater, but with changes in sensitivity, by adaptation of the carrier and calibration solutions to the salinity of the samples.

Specifies a procedure for water, readily applicable to field testing; it is based on measurement of the colour intensity by visual comparison of the colour with a scale of standards which is regularly calibrated. Sea water and waters containing bromides and iodides comprise a group for which special procedures are required. The procedure is applicable to concentrations, in terms of chlorine, from 0,000 4 to 0,07 mmol/l total chlorine and at higher concentrations by dilution of samples. Interferences of the procedure are noted.

Migrated from Progress Sheet (TC Comment) (2000-07-10): N 315: New TD (980916)

Migrated from Progress Sheet (TC Comment) (2000-07-10): new TD 49 in BP (bli 991125)

This European Standard specifies a method for the determination of mercury in drinking, surface, ground and rain water.
NOTE   It is permissible, that this standard is also applied to industrial and municipal waste water after an additional digestion step under appropriate conditions.
The potential linear dynamic range is approximately 1 ng/l to 100 µg/l. In practice, the working range is often from 10 ng/l to 10 µg/l.
Samples containing mercury at concentrations higher than the working range can be analysed following appropriate dilution of the sample.
The method detection limit (MDL) will be dependent on the selected operating conditions and calibration range. With high purity reagents a MDL of less than 1 ng/l is obtainable.
The relative standard deviation is typically less than 5 % for concentrations greater than twenty times the method detection limit.
The sensitivity of this method is dependent on the selected operating conditions.