EN ISO 23821:2022

Cosmetics - Analytical methods - Determination of traces of mercury in cosmetics by atomic absorbtion spectrometry (AAS) cold vapour technology after pressure digestion (ISO 23821:2022)

This document specifies a method for determination of mercury in cosmetics by means of cold vapour atomic absorption spectrometry (AAS) with a prior pressure digestion.

Kosmetische Mittel - Untersuchungsverfahren - Bestimmung von Quecksilberspuren in kosmetischen Mitteln durch Kaltdampf-Atomabsorptionsspektrometrie (AAS) nach Druckaufschluss (ISO 23821:2022)

Dieses Dokument legt ein Verfahren zur Bestimmung von Quecksilber in kosmetischen Mitteln mittels Kaltdampf-Atomabsorptionsspektrometrie (AAS) nach Druckaufschluss fest.

Cosmétiques - Méthodes d’analyse - Dosage des traces de mercure dans les cosmétiques par la technique de spectrométrie d’absorption atomique (SAA) de vapeur froide après digestion sous pression (ISO 23821:2022)

Le présent document spécifie une méthode de dosage du mercure dans les cosmétiques par spectrométrie d'absorption atomique (SAA) de vapeur froide après digestion sous pression.

Kozmetika - Analizne metode - Določevanje živega srebra v sledovih v kozmetičnih izdelkih z atomsko absorpcijsko spektrometrijo (AAS) s tehniko hladnih par po razklopu pod tlakom (ISO 23821:2022)

Cilj tega standarda je zagotoviti postopek za določanje živega srebra v kozmetičnih izdelkih z atomsko adsorpcijo s hladnimi parami (AAS) po razklopu pod tlakom.
Postopek je bil potrjen leta 2015 z večlaboratorijsko študijo v kombinaciji s postopkom določanja živega srebra s hladnimi parami AAS, v kateri je sodelovalo osem laboratorijev. Skupno je bilo analiziranih sedem vzorcev, ki so predstavljali različne matrice (šminka, barvilo za tetoviranje, losjon za telo, zobna pasta, senčilo za oči in vodica, ki se uporablja pri ličenju) z različnimi vsebnostmi živega srebra med 0,110 mg/kg in 5,84 mg/kg.

General Information

• Status: Published
• Publication Date: 13-Sep-2022
• ICS: 71.100.70 - Cosmetics. Toiletries
• Technical Committee: CEN/TC 392 - Cosmetics
• Drafting Committee: CEN/TC 392/WG 1 - Analytical methods
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 14-Sep-2022
• Due Date: 01-Nov-2021
• Completion Date: 14-Sep-2022
• Ref Project: SIST EN ISO 23821:2023 - Cosmetics - Analytical methods - Determination of traces of mercury in cosmetics by atomic absorbtion spectrometry (AAS) cold vapour technology after pressure digestion (ISO 23821:2022)

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2023
Kozmetika - Analizne metode - Določevanje živega srebra v sledovih v kozmetičnih
izdelkih z atomsko absorpcijsko spektrometrijo (AAS) s tehniko hladnih par po
razklopu pod tlakom (ISO 23821:2022)
Cosmetics - Analytical methods - Determination of traces of mercury in cosmetics by
atomic absorbtion spectrometry (AAS) cold vapour technology after pressure digestion
(ISO 23821:2022)
Kosmetische Mittel - Untersuchungsverfahren - Bestimmung von Quecksilberspuren in
kosmetischen Mitteln durch Kaltdampf-Atomabsorptionsspektrometrie (AAS) nach
Druckaufschluss (ISO 23821:2022)
Cosmétiques - Méthodes d’analyse - Dosage des traces de mercure dans les
cosmétiques par la technique de spectrométrie d’absorption atomique (SAA) de vapeur
froide après digestion sous pression (ISO 23821:2022)
Ta slovenski standard je istoveten z: EN ISO 23821:2022
ICS:
71.040.50 Fizikalnokemijske analitske Physicochemical methods of
metode analysis
71.100.70 Kozmetika. Toaletni Cosmetics. Toiletries
pripomočki
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 23821
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2022
EUROPÄISCHE NORM
ICS 71.100.70
English Version
Cosmetics - Analytical methods - Determination of traces
of mercury in cosmetics by atomic absorbtion
spectrometry (AAS) cold vapour technology after pressure
digestion (ISO 23821:2022)
Cosmétiques - Méthodes d'analyse - Dosage des traces Kosmetische Mittel - Untersuchungsverfahren -
de mercure dans les cosmétiques par la technique de Bestimmung von Quecksilberspuren in kosmetischen
spectrométrie d'absorption atomique (SAA) de vapeur Mitteln durch Atomabsorptionsspektrometrie (AAS)
froide après digestion sous pression (ISO 23821:2022) Kaltdampftechnologie nach Druckaufschluss (ISO
23821:2022)
This European Standard was approved by CEN on 23 July 2022.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23821:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 23821:2022) has been prepared by Technical Committee ISO/TC 217
"Cosmetics" in collaboration with Technical Committee CEN/TC 392 “Cosmetics” the secretariat of
which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2023, and conflicting national standards shall
be withdrawn at the latest by March 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 23821:2022 has been approved by CEN as EN ISO 23821:2022 without any modification.

INTERNATIONAL ISO
STANDARD 23821
First edition
2022-08
Cosmetics — Analytical methods —
Determination of traces of mercury
in cosmetics by atomic absorbtion
spectrometry (AAS) cold vapour
technology after pressure digestion
Cosmétiques — Méthodes d’analyse — Dosage des traces de mercure
dans les cosmétiques par la technique de spectrométrie d’absorption
atomique (SAA) de vapeur froide après digestion sous pression
Reference number
ISO 23821:2022(E)
ISO 23821:2022(E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 23821:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 1
6 Apparatus and equipment . 3
7 Procedure .4
7.1 General . 4
7.2 Preparation of samples . 4
7.3 Pressure assisted digestion . 4
7.3.1 General . 4
7.3.2 Preparation of sample by digestion — General case. 4
7.3.3 Preparation of sample by digestion — Specific cases . 4
7.3.4 Microwave digestion procedure . 5
7.3.5 Preparation of measurement solutions . . 5
7.4 Atomic absorption spectrometry (cold vapour AAS) . 6
7.4.1 Spectrometry settings . . . 6
7.4.2 Example for AAS determination using cold vapour technology . 6
7.5 Quality control of the analysis . . 6
8 Evaluation . 6
8.1 Calculation . 6
8.2 Limit of quantification . 7
8.3 Reliability of the method . 7
9 Test report . 7
10 Alternative stabilizing reagents . 8
11 Short-term stabilization when measuring with potassium permanganate solution .8
Annex A (informative) Performance of the method determined via ISO 5725 statistical
approach . 9
[4]
Annex B (informative) Common interlaboratory test results of ISO 23674 and this
document .12
Bibliography .15
iii
ISO 23821:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 217, Cosmetics, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 392, Cosmetics, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
ISO 23821:2022(E)
Introduction
This document has been developed in parallel with ISO 23674. Knowing this, an interlaboratory test
using either one or the other method was performed on same tailor-made cosmetic products in order to
establish that both methods fulfilled the same requirements (see Annex B). This method was validated
[7]
by means of an interlaboratory test according to ISO 5725-2 using lipstick, body lotion, toothpaste
and eyeshadow, with a mercury concentration in the range of 0,110 mg/kg to 5,84 mg/kg. Statistical
characteristics regarding this interlaboratory test are provided in Annex A, Table A.1.
v
INTERNATIONAL STANDARD ISO 23821:2022(E)
Cosmetics — Analytical methods — Determination of
traces of mercury in cosmetics by atomic absorbtion
spectrometry (AAS) cold vapour technology after pressure
digestion
1 Scope
This document specifies a method for determination of mercury in cosmetics by means of cold vapour
atomic absorption spectrometry (AAS) with a prior pressure digestion.
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 3696, Water for analytical laboratory use — Specification and test methods
3 Terms and definitions
No terms and definitions are listed in this document.
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 https:// www .electropedia .org/
4 Principle
As a first step, the finished cosmetic product is digested in a closed vessel at high temperatures and
pressure using mineral acids. Pressure digestion is carried out at a temperature of 200 °C obtained by
means of microwave-assisted heating.
After digestion of the cosmetics, the concentration of mercury is determined by quantification using
the AAS cold vapour technology.
During mineralisation of the sample, it is not possible to dissolve all cosmetics without residues,
depending on their type and composition. In order to obtain comparable results, it is absolutely
mandatory to conform with the conditions specified for this method.
The measurement solution is transferred to the reaction vessel of the mercury analysis unit. From
there, mercury is rinsed out into the cuvette of the AAS instrument with the help of a carrier gas flow
after reduction with divalent tin or sodium borohydride. Absorption at the mercury line of 253,7 nm is
used as a measure for mercury concentration in the cuvette. By using a gold/platinum mesh (amalgam
technology) for concentration of the rinsed-off mercury prior to measurement in the cuvette, it is
possible to achieve lower limits of quantification (LOQs).
5 Reagents
The reagents and the water used shall be free of mercury to such an extent that the analysis is not
impaired. Unless specified otherwise, pure-analysis chemicals shall be used, and solutions are
ISO 23821:2022(E)
understood to be aqueous solutions. Use water conforming to Grade 1 of ISO 3696 (conductivity below
0,1 µS/cm at 25 °C).
5.1 Hydrochloric acid, minimum mass fraction w = 30 %, density = 1,15 g/ml, suitable for elemental
analysis.
5.2 Nitric acid, minimum w = 65 %, density = 1,4 g/ml, suitable for elemental analysis.
5.3 Diluted nitric acid, produced by mixing nitric acid (5.2) at a ratio of approximately 1 + 9 with
water respectively.
5.4 Reducing agents, for example tin(II) chloride or sodium borohydride.
Alternating operation with both reducing agents (5.4.1 and 5.4.2) is not recommended. For this purpose,
the appropriate information from the manufacturer of the instrument shall be followed.
The mass concentrations of the reducing agent solutions can vary, depending on the system. The
corresponding data of the manufacturer of the instrument shall be conformed with.
5.4.1 Tin(ll) chloride solution, for example mass concentration ρ = 100 g/l.
Weigh 50 g tin(ll) chloride, SnCI ·2H O in a 500 ml volumetric flask, dissolve in approximately 100 ml
2 2
hydrochloric acid (5.1), and fill up to 500 ml with water. The solution shall be freshly prepared prior to
use.
5.4.2 Sodium borohydride solution, for example ρ = 30 g/l.
Dissolve 3 g of sodium borohydride and 1 g of sodium hydroxide pellets in water and fill up with 100 ml
water. The solution shall be freshly prepared every day and filtered prior to use.
WARNING — Compliance with the safety instructions is mandatory when working with sodium
borohydride. Sodium borohydride forms hydrogen when combined with water and especially
on reaction with acids, which can result in an explosive air/hydrogen mixture. A fixed exhaust
system shall be installed/present in the area where measurements are carried out.
5.5 Stabilization
The standard, calibration and sample digestion solutions are stabilized with hydrochloric acid (5.1). It
is recommended to set a hydrochloric acid concentration of around ω = 1 % in the solutions. Alternative
stabilizing reagents can also be used (see Clause 10).
5.6 Mercury stock solution, mercury ρ = 1 000 mg/l.
The stock solution is commercially available. It is recommended to use certified stock solutions.
5.7 Mercury standard solutions
Dilute the stock solution to the concentrations required for calibration and add the necessary amount
of stabilisation reagent (5.5). In doing so, select concentrations that the linear range of the reference
function is not exceeded. It is recommended to use at least three (3) standard solutions with different
concentrations.
The acid concentration in the standard solutions shall correspond to the acid concentration of the
measurement solution. Mercury standard solutions have a rather short shelf life, even at higher
concentrations; therefore, they shall be freshly prepared every day.
ISO 23821:2022(E)
5.8 Calibration blank solution
The calibration blank solution shall contain water, the same amount of stabilisation reactant as the
mercury standard solutions (5.7) per litre and the quantities of nitric acid (5.2) and hydrochloric acid
(5.1) that correspond to the acid concentrations in the measurement solution.
6 Apparatus and equipment
For the determination of mercury all apparatus and equipment that come into direct contact with the
sample and the solutions used shall be thoroughly pre-treated to ensure minimisation of contamination.
The following steps are recommended for cleaning: Rinse with drinking water, treat with a scouring
agent solution, repeat rinsing with drinking water and soak in diluted nitric acid (5.3) over night or
a prolonged period. Prior to use, rinse the apparatus with ultrapure water and dry. Steaming of
chemically inert vessels (e.g. made of quartz glass) using nitric acid (5.2) is an effective cleaning method
and is regularly used in element trace analysis. To prevent contamination and adsorption, only use lab
materials made with borosilicate or quartz glass.
6.1 Digestion vessels.
Use commercially available, safety-tested pressure vessels and inserts made of acid resistant and, low-
contamination materials. The assembled vessels shall be able to safely withstand temperatures up to
at least 200 °C and pressures up to at least 40 bar. The specific size of the vessels is not mandatory and
depends on the used type of microwave.
Dedicated digestion vessels are recommended for the digestion of cosmetic samples, which may have
high levels of elements to be determined. To avoid memory effects, perform a blank digestion to clean
vessels after digesting highly loaded samples, before digesting sequent samples.
6.2 Microwave assisted digestion instruments.
Microwave-heated systems shall be equipped with a temperature measurement unit, which
simultaneously regulates the power control of the microwave. Reliable temperature measurement
is obtained, for example, through measurement sensors inserted into the pressure vessel. Only use
microwave-assisted digestion instruments equipped with temperature sensors and calibrate the
temperature sensor before use.
6.3 Membrane filter, 0,45 µm pore size.
The membrane filter used shall be inert with regard to the acid concentration of the measurement
solution and shall not bring any contamination into the measurement solution or adsorption of the
analytes. Several types of membrane material are commercially available (e.g. PTFE, PP) and their fit
for purpose shall be verified by means of appropriate measurements (e.g. blanks, QC samples).
6.4 Atomic absorption spectrometer, optionally available with background correction and
including accessories for cold vapour technology or amalgam technology.
Flow injection systems can be used as an alternative of manual processes.
6.5 Element-specific light for mercury
Measurement at 253,7 nm.
...