OIV-MA-AS1-02 General remarks

1. Clear wine or must, must be used for chemical and physical analysis.  If the wine or the must is cloudy, it is first filtered through filter paper in a covered funnel or centrifuged in a closed container.  This operation must be stated on any required documentation.

2. The reference of the method employed for each determination must be on any required documentation.

3. Units of measure for the various magnitudes (volume, mass, concentration, temperature, pressure, etc.) shall be in accordance with the recommenda­tions of the IUPAC (International Union for Pure and Applied Chemistry).

4. In respect of reagents and titration solutions used, unless otherwise required in the text, the chemicals used are to be of "analytical grade" and the water is to be distilled or of equivalent purity.

5. Enzyme methods, and the determination of a number of parameters, are to be based on absolute measurements of absorbance, which requires spectrophotometers to be calibrated for wavelengths and absorbance. Wavelength may be calibrated by use of Hg lines: 239.94, 248.0, 253.65, 280.4, 302.25, 313.16, 334.15, 365.43, 404.66, 435.83, 546.07, 578.0, and 1014.0 nm.  Absorbance may be calibrated by means of commercial reference solutions, obtained from suitable suppliers, or neutral density filters.

6. The essential bibliographical references are given. The references to working documents of the Sub‑Commission are marked 'F.V., O.I.V.' (feuillets verts or 'green pages'), followed by the year of publication and the number of the document.

OIV-MA-AS1-03 Classification of analytical methods

CATEGORY I* (CRITERION BENCHMARK METHOD): A method which determines a value that can be arrived at only by implementing the method per se and which serves, by definition, as the only method for establishing the accepted value of the parameter measured (e.g., alcoholometric  content, total acidity, volatile acidity).

CATEGORY II* (BENCHMARK METHOD): A category II method is designated  as the Benchmark Method in cases where category I methods cannot be used. It should be selected from category III methods (as defined below). Such methods should be recommended for use in cases of disputes and for calibration purposes. (e.g., potassium, citric acid).

CATEGORY III* (APPROVED ALTERNATIVE METHODS): A category III Method meets  all of the criteria specified by the Sub-Committee on Methods of Analysis and is used for monitoring, inspection and regulatory purposes (e.g., enzymatic determinations of glucose and fructose).

CATEGORY IV (AUXILIARY METHOD): A category IV Method is a conventional or recently-implemented technique, with respect to which the Sub-Committee on Methods of Analysis has not as yet specified the requisite criteria (e.g., synthesized coloring agents, measurement of oxidation-reduction potential).

* Methods requiring formal approval in accordance with the procedures in force at the Sub-Commission of Methods of Analysis.

OIV-MA-AS1-04 Matrix effect for metals content analysis using atomic absorption

The GENERAL ASSEMBLY,

In consideration of Article 5, Paragraph 4 of the International Standardization Convention on Methods of Wine Analysis and Rating of October 13, 1954,

Action on the proposal of the Sub-Committee on International Methods of Analysis and Rating of Wines,

CONSIDERING that the methods described in the Compendium of International Methods of Wine and Must Analysis and entailing the use of reference solutions are implemented for dry wines,

DRAWS the attention of users to the fact that deviations may be observed in other cases involving the presence of sugars or sugar derivatives,

DECIDES that it is therefore necessary to undertake analyses using the quantified additions method. A minimum of three aliquot portions of the sample containing various additions should be used.

DECIDES to supplement the methods for analyzing metals (iron, lead, zinc, silver, cadmium) and arsenic with a description of the quantified additions technique, when the matrix effect so requires.

OIV-MA-AS1-05a Provisions on the use of proprietary methods that should be adopted by the OIV

Definition of a Proprietary Method of Analysis

For OIV purposes, a proprietary method of analysis is one that contains protected intellectual property preventing full disclosure of information about the method and/or where the intellectual property owner restricts the use or distribution of the method or materials for its performance such that no alternative source of these would be available. It does not extend to a method which is subject only to copyright.

Requirements

The OIV requires the method sponsors to provide relevant data to enable the SCMA (“Methods of Analysis” Sub-Commission) or another expert group to carry out an assessment. Following assessment, the SCMA, or another expert group, may submit methods of analysis that are proprietary, or are based on proprietary aspects, to the OIV General Assembly, for their approval, according to the following procedures.

a)      A proprietary method should not be endorsed if a suitable non-proprietary method of analysis is available that has been or could be endorsed and that has similar or better performance characteristics. This should ensure that no approach is taken that could suggest that a proprietary method is endorsed by the OIV to the detriment of other potential methods; where possible preference should be given to adopting appropriate method criteria rather than endorsing a specific proprietary method of analysis.

b)      Whilst respecting the necessity for reasonable protection of intellectual property, sufficient information should be available to enable reliable use of the method by analysts and to enable evaluation of the performance of the method by the SCMA or another expert group. In particular cases this may extend beyond performance data, for example, including details of the operating principle, at the sole discretion of the SCMA or another expert group.

c)      Preference should be given to endorsing those methods of analysis where the reagents and/or apparatus are described in the method, to the extent that either laboratories or other manufacturers could produce these themselves; alternatively, details enabling them to acquire these themselves would also suffice.

d)      Method performance criteria required for proprietary methods are the same as those for non-proprietary methods. The performance criteria should be those stipulated above. If appropriate, information about the effect of variability of the reagents used should be provided.

e)      After endorsing, any changes that may influence performance characteristics must be reported to the SCMA or another expert group for consideration.

f)       A method with some parts that constitute protected proprietary information should be fully and collaboratively validated according to the OIV standards appearing in Annex A of the Compendium of International Methods of Analysis of Wines and Musts. The results of such studies will be made available for the SCMA or another expert group.

g)      The manufacturer or the party submitting for evaluation a proprietary method should demonstrate to the satisfaction of the SCMA or another expert group that the fundamental principles and characteristics for the execution of the method may be made available to all interested parties.

h)      The SCMA or another expert group may decline to assess a proprietary method if intellectual property restrictions unduly limit research into determining the method properties, scope and validity or development of improvements to the technology.

i)        If suitable non-proprietary methods become available and endorsed, the status of the previously endorsed proprietary method should be reviewed and revised if necessary.