ISO 23883:2026

International
Standard
ISO 23883
First edition
Meat, fish and their
2026-05
products — Determination of
fluoroquinolone residue content
— High performance liquid
chromatography-tandem mass
spectrometry method
Viandes, poissons et leurs produits dérivés — Détermination
de la teneur en résidus de fluoroquinolone — Méthode par
chromatographie liquide à haute performance couplée à la
spectrométrie de masse en tandem
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents and materials . 1
6 Apparatus . 3
7 Sampling . 3
8 Preparation of samples . 3
8.1 Preparation of test sample .3
8.2 Preparation of method blank sample .3
9 Procedure . 3
9.1 Extraction .3
9.2 Clean-up .4
9.3 Calibration curve .4
9.4 Determination .4
9.4.1 Liquid chromatography operating condition.4
9.4.2 Mass spectrometer operating condition .4
9.4.3 Identification criteria .5
9.4.4 Quantification criteria .5
9.5 Blank test .5
10 Calculation and expression of the results . 5
11 Precision . 6
11.1 Repeatability and reproducibility .6
11.2 Limit of detection .6
11.3 Limit of quantification .6
12 Test report . 6
Annex A (informative) Information of fluoroquinolones . 7
Annex B (informative) Equipment reference parameters . 8
Annex C (informative) Collaborative interlaboratory test results. 9
Bibliography . 14

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 6, Meat,
poultry, fish, eggs and their products.
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
Introduction
Fluoroquinolones are synthetic broad-spectrum antimicrobial agents extensively used as a veterinary
drug for the prevention and treatment of bacterial infections in food-producing animals. Their widespread
application, particularly in husbandry and aquaculture, has raised concerns about the presence of residual
amounts in edible animal-derived products. Residues of fluoroquinolones in food can cause adverse health
effects for human beings, including allergies and disturbances to the intestinal flora. More critically,
prolonged exposure to sub-therapeutic levels of these compounds through the food chain is considered to be
a contributing factor to the emergence and dissemination of antimicrobial resistance.
To safeguard public health and ensure the safety of animal-derived food, many regulatory authorities have
established maximum residue limits (MRLs) for various fluoroquinolone compounds in meat, fish and
related products. The effective enforcement of these limits depends on the availability of sensitive, accurate
and validated analytical methods capable of detecting trace levels of residues in complex biological matrices.
Several analytical approaches have been developed for the determination of fluoroquinolone residues,
including microbiological inhibition tests, immunoassays and instrumental techniques. While
microbiological and immunological methods are relatively simple and cost-effective, they often suffer from
limited specificity and sensitivity, as well as susceptibility to matrix interferences. In contrast, instrumental
methods such as high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) offer
significant advantages in terms of selectivity, precision and detection capability. The ability of HPLC-MS/MS
to simultaneously quantify multiple fluoroquinolone compounds with high sensitivity makes it particularly
suitable for regulatory monitoring and confirmatory analysis across a variety of food matrices.

v
International Standard ISO 23883:2026(en)
Meat, fish and their products — Determination of
fluoroquinolone residue content — High performance liquid
chromatography-tandem mass spectrometry method
1 Scope
This document specifies the determination of fluoroquinolone residue content in meat, fish and their
products by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method.
This document is applicable to the determination of enrofloxacin, ciprofloxacin, norfloxacin, ofloxacin and
pefloxacin residues in meat, fish and their products, including livestock and poultry.
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 terminology 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
The fluoroquinolone residues in the test sample are extracted with acidified acetonitrile, purified by
n-hexane extraction, determined by high performance liquid chromatography-tandem mass spectrometry,
and quantified by an internal standard method.
5 Reagents and materials
Use only reagents of recognized analytical grade, unless otherwise specified.
5.1 Water, conforming to ISO 3696, grade 1 or equivalent.
5.2 Methanol, LC grade.
5.3 Acetonitrile, LC grade.
5.4 Formic acid, LC grade.
5.5 Ammonium acetate, LC grade.

5.6 Anhydrous sodium sulfate.
5.7 n-Hexane, LC grade.
5.8 Acidified acetonitrile, V/V = 1:99.
Add 1 ml of formic acid into 99 ml of acetonitrile.
5.9 Ammonium acetate-formic acid solution, c(CH COONH ) = 4,0 mmol/l.
3 4
Weigh 0,154 g of ammonium acetate into a 500 ml volumetric flask. Add 0,5 ml formic acid and dilute with
water to the mark.
5.10 Mobile phase mixture, V/V = 2:8.
Add 20 ml of methanol into 80 ml of ammonium acetate-formic acid solution (5.9).
5.11 Fluoroquinolone standard reference, certified reference material, see Annex A.
5.12 Fluoroquinolone isotope internal reference, certified reference material, see Annex A.
5.13 Standard stock solution, ρ = 1,0 mg/ml.
Weigh, to the nearest 0,01 mg, approximately 10 mg of each fluoroquinolone (5.11) into a 10 ml volumetric
flask respectively. Add 0,2 ml formic acid and dilute with methanol to the mark. This solution is stable for six
months when stored in the dark at a temperature below −18 °C.
5.14 Internal standard stock solution, ρ = 0,5 mg/ml.
Weigh, to the nearest 0,01 mg, approximately 5,0 mg of deuterated enrofloxacin, deuterated ciprofloxacin,
deuterated norfloxacin, deuterated ofloxacin and deuterated pefloxacin internal standard substance (5.12)
into a 10 ml volumetric flask. Add 0,2 ml formic acid and dilute with methanol to the mark. This solution is
stable for six months when stored in the dark at a temperature below −18 °C.
5.15 Mixed intermediate standard solution, ρ = 10 μg/ml.
Measure an appropriate amount of each standard stock solution, dilute it with methanol to make a 10 μg/
ml mixed intermediate standard solution. This solution is stable for one month when stored in the dark at a
temperatur
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