Collaborative study Method validation for the determination of free sulphur dioxide, OIV-MA-AS323-04A (update) Update to the method validation for the determination of total sulphur dioxide, OIV-MA-AS323-04A (update)
OIV-OENO 661-2021 Collaborative study- Method validation for the determination of free sulphur dioxide, OIV-MA-AS323-04A1 (update). Update to the method validation for the determination of total sulphur dioxide, OIV-MA-AS323-04A2 (update)
THE GENERAL ASSEMBLY,
IN VIEW OF the Article 2, paragraph 2 b) iv of the Agreement of 3rd April 2001 establishing the International Organisation of Vine and Wine,
AT THE PROPOSAL OF the “Methods of Analysis” Sub-Commission,
CONSIDERING the two draft resolutions already adopted in 2018 regarding the update to the method for the determination of sulphur dioxide, distinguishing the Type IV method for the determination of free sulphur dioxide (Resolution OIV-OENO 591A-2018) from the Type II method for the determination of total sulphur dioxide (Resolution OIV-OENO 591B-2018),
CONSIDERING the need for validation of the method for the determination of free sulphur dioxide, OIV-MA-AS323-04A1 (update), and the need for updated validation of the method for the determination of total sulphur dioxide, OIV-MA-AS323-04A2 (update),
DECIDES to complete methods OIV-MA-AS323-04A1 on free sulphur dioxide and OIV-MA-AS323-04A2 on total sulphur dioxide in the Compendium of International Methods of Wine and Must Analysis with the following collaborative study:
Collaborative study
Method validation for the determination of free sulphur dioxide, OIV-MA-AS323-04A1 (update). Update to the method validation for the determination of total sulphur dioxide, OIV-MA-AS323-04A2 (update)
1. Scope of application
An international collaborative study, in accordance with Resolution OIV-OENO 6-2000, for the validation of updates to the methods for the determination of free sulphur dioxide and total sulphur dioxide (OIV-MA-AS323-04A), based on the decision of the OIV “Methods of Analysis” Sub-Commission, April 2018.
2. Standard references
- Update (draft) to the OIV-MA-AS323-04A methods,
- ISO 5725,
- Resolution OIV-OENO 6-2000.
3. Protocol
A total of 20 samples were prepared using homogeneous volumes of 10 wines from various wine regions in France and Portugal. Each sample was made up twice (the second as a blind duplicate), according to the double-blind principle.
The samples were prepared between 18 and 20 June 2018, then shipped without delay to the participating laboratories.
|
Sample no. |
Blind duplicate no. |
Nature of sample |
|
A |
1-14 |
Dry white wine |
|
B |
2-16 |
Dry white wine |
|
C |
3-19 |
Dry rosé wine |
|
D |
4-12 |
Dry rosé wine |
|
E |
5-20 |
Dry red wine |
|
F |
6-18 |
Dry red wine |
|
G |
7-11 |
Dry red wine |
|
H |
8-15 |
White liqueur wine |
|
I |
9-17 |
Red liqueur wine |
|
J |
10-13 |
Red liqueur wine |
The analyses were carried out simultaneously by all participating laboratories between 16 and 20 July 2018. Samples were kept in refrigerated cabinets by all laboratories between the date of reception and the date of analysis, according to the protocols sent.
The following laboratories provided their results:
|
Laboratory |
City |
Country |
|
Estación de Viticultura e Enoloxía de Galicia |
Leiro (Ourense) |
Spain |
|
Laboratorio arbitral agroalimentario |
Madrid |
Spain |
|
ASAE |
Lisbon |
Portugal |
|
SCL Montpellier |
Montpellier Cdex 5 |
France |
|
HBLA und BA für Wein- und Obstbau |
Klosterneuburg |
Austria |
|
Laboratorio de Salud Pública |
Madrid |
Spain |
|
Laboratorio Agroambiental de Zaragoza |
Zaragoza |
Spain |
|
Laboratoire SCL Bordeaux |
Pessac Cedex - CS 98080 |
France |
|
Unione Italiana Vini Servizi |
Verona |
Italy |
|
Laboratorio Agroalimentario de Valencia |
Burjassot (Valencia) |
Spain |
|
Agroscope |
Nyon |
Switzerland |
|
Laboratoires Dubernet |
Montredon des Corbières |
France |
|
Laboratoire Dioenos Rhône |
Orange |
France |
|
Laboratoire Natoli |
Saint Clément de Rivière |
France |
NB: The order of laboratories in the table does not correspond with the order in the following tables, in order to preserve the anonymity of results.
4. Free sulphur dioxide
4.1. Free 
data
|
Free SO2 (mg/L) |
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
||||||||||
|
Sample |
1 |
14 |
2 |
16 |
3 |
19 |
4 |
12 |
5 |
20 |
6 |
18 |
7 |
11 |
8 |
15 |
9 |
17 |
10 |
13 |
|
Labo 3 |
31 |
36 |
18 |
18 |
21 |
23 |
20 |
18 |
6 |
6 |
20 |
17 |
5 |
6 |
||||||
|
Labo 5 |
37 |
35 |
21 |
24 |
24 |
25 |
20 |
20 |
8 |
7 |
20 |
20 |
3 |
4 |
||||||
|
Labo 6 |
4 |
1 |
38 |
33 |
21 |
20 |
20 |
26 |
19 |
20 |
7 |
6 |
21 |
19 |
7 |
8 |
1 |
3 |
1 |
1 |
|
Labo 7 |
1 |
1 |
37 |
40 |
20 |
22 |
24 |
26 |
20 |
22 |
9 |
8 |
20 |
23 |
8 |
8 |
2 |
1 |
1 |
1 |
|
Labo 8 |
31 |
32 |
18 |
19 |
23 |
22 |
22 |
20 |
6 |
7 |
19 |
20 |
5 |
3 |
1 |
1 |
||||
|
Labo 9 |
35 |
34 |
23 |
19 |
25 |
24 |
21 |
24 |
17 |
17 |
||||||||||
|
Labo 10 |
2 |
1 |
35 |
34 |
20 |
21 |
24 |
24 |
22 |
21 |
9 |
8 |
21 |
20 |
7 |
7 |
2 |
2 |
1 |
1 |
|
Labo 11 |
0 |
0 |
33 |
30 |
17 |
11 |
22 |
16 |
16 |
21 |
6 |
4 |
15 |
19 |
6 |
3 |
1 |
1 |
0 |
0 |
|
Labo 15 |
15 |
19 |
15 |
13 |
18 |
20 |
8 |
16 |
6 |
5 |
8 |
15 |
5 |
5 |
||||||
|
Labo 17 |
0 |
0 |
37 |
38 |
24 |
26 |
28 |
28 |
26 |
23 |
8 |
8 |
24 |
22 |
7 |
7 |
1 |
2 |
0 |
0 |
|
Labo 18 |
0 |
4 |
33 |
31 |
21 |
11 |
23 |
27 |
15 |
19 |
6 |
4 |
9 |
20 |
3 |
4 |
1 |
1 |
0 |
0 |
|
Labo 20 |
0 |
0 |
32 |
32 |
20 |
19 |
21 |
21 |
29 |
21 |
8 |
8 |
20 |
18 |
12 |
4 |
1 |
1 |
0 |
0 |
|
Labo 21 |
2 |
1 |
33 |
38 |
19 |
15 |
25 |
22 |
19 |
21 |
6 |
6 |
19 |
20 |
8 |
7 |
2 |
1 |
0 |
0 |
Results left blank were rendered non-quantifiable (< limit of quantification).
|
Result removed by the COCHRAN test at 5% |
|
|
Result removed by the GRUBBS test at 5% |
4.2. Free SO2 results
|
Free SO2 (mg/L) |
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
|
No. of laboratories selected |
7 |
9 |
11 |
10 |
10 |
12 |
11 |
11 |
9 |
8 |
|
No. of repetitions |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
|
Min. |
0 |
31.5 |
14 |
19 |
17 |
5 |
17 |
3.5 |
1 |
0 |
|
Max. |
2.5 |
38.5 |
25 |
28 |
24.5 |
8.5 |
23 |
8 |
2 |
1 |
|
Mean |
0.9 |
34.2 |
19.8 |
23.4 |
20.6 |
6.8 |
19.6 |
5.7 |
1.4 |
0.4 |
|
Standard deviation |
0.98 |
2.67 |
2.91 |
2.46 |
2.04 |
1.31 |
1.77 |
1.72 |
0.42 |
0.52 |
|
Repeatability variance |
0.79 |
1.67 |
2.59 |
1.20 |
2.60 |
0.58 |
2.23 |
0.82 |
0.39 |
0.00 |
|
Inter-laboratory standard deviation |
0.98 |
2.67 |
2.91 |
2.46 |
2.04 |
1.31 |
1.77 |
1.72 |
0.42 |
0.52 |
|
Reproducibility variance |
1.35 |
7.97 |
9.76 |
6.64 |
5.46 |
2.00 |
4.25 |
3.38 |
0.37 |
0.27 |
|
Repeatability standard deviation |
0.89 |
1.29 |
1.61 |
1.10 |
1.61 |
0.76 |
1.49 |
0.90 |
0.62 |
0.00 |
|
r limit |
2.48 |
3.61 |
4.51 |
3.07 |
4.51 |
2.14 |
4.18 |
2.53 |
1.75 |
0.00 |
|
Repeatability %CV (k=2) |
191 |
8 |
16 |
9 |
16 |
23 |
15 |
32 |
90 |
0 |
|
Reproducibility standard deviation |
1.16 |
2.82 |
3.12 |
2.58 |
2.34 |
1.41 |
2.06 |
1.84 |
0.61 |
0.52 |
|
R limit |
3.25 |
7.90 |
8.75 |
7.22 |
6.54 |
3.96 |
5.78 |
5.15 |
1.70 |
1.45 |
|
Reproducibility %CV (k=2) |
250 |
16 |
32 |
22 |
23 |
42 |
21 |
64 |
87 |
276 |
|
Horwitz PRSDR (%) |
16.18 |
9.40 |
10.21 |
9.95 |
10.15 |
12.00 |
10.22 |
12.30 |
15.23 |
18.55 |
|
Horwitz sR |
0.15 |
3.22 |
2.02 |
2.33 |
2.09 |
0.81 |
2.00 |
0.70 |
0.21 |
0.07 |
|
Horwitz R |
0.42 |
9.10 |
5.71 |
6.59 |
5.91 |
2.29 |
5.67 |
1.99 |
0.60 |
0.20 |
|
Horwitz Ratio |
7.64 |
0.87 |
1.53 |
1.10 |
1.11 |
1.73 |
1.02 |
2.58 |
2.84 |
7.37 |
 |
|
Figure 1: Modelling of the repeatability coefficient of variation, %CV(r) (k=2), as a function of the concentration, C:
|
 |
|
Figure 2: Modelling of the inter-laboratory reproducibility coefficient of variation, %CV(R) (k=2), as a function of concentration, C:
|
5. Total sulphur dioxide
5.1. Total SO2 data
|
Total SO2 (mg/L) |
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
||||||||||
|
Sample |
1 |
14 |
2 |
16 |
3 |
19 |
4 |
12 |
5 |
20 |
6 |
18 |
7 |
11 |
8 |
15 |
9 |
17 |
10 |
13 |
|
Labo 3 |
128 |
127 |
72 |
73 |
128 |
131 |
61 |
59 |
28 |
28 |
57 |
56 |
102 |
102 |
47 |
45 |
||||
|
Labo 5 |
122 |
121 |
68 |
71 |
112 |
114 |
42 |
53 |
22 |
22 |
51 |
42 |
102 |
101 |
35 |
34 |
||||
|
Labo 6 |
1 |
128 |
131 |
72 |
72 |
126 |
131 |
53 |
54 |
22 |
20 |
42 |
49 |
98 |
99 |
31 |
34 |
3 |
1 |
|
|
Labo 7 |
3 |
3 |
131 |
131 |
70 |
74 |
130 |
131 |
54 |
59 |
26 |
23 |
46 |
48 |
106 |
101 |
37 |
40 |
1 |
1 |
|
Labo 8 |
2 |
1 |
125 |
127 |
72 |
72 |
129 |
128 |
58 |
57 |
22 |
23 |
46 |
45 |
97 |
99 |
42 |
39 |
1 |
1 |
|
Labo 9 |
120 |
128 |
77 |
75 |
132 |
108 |
71 |
59 |
21 |
25 |
44 |
47 |
110 |
99 |
38 |
48 |
||||
|
Labo 10 |
2 |
2 |
130 |
130 |
74 |
76 |
130 |
130 |
61 |
61 |
28 |
32 |
55 |
56 |
103 |
104 |
43 |
44 |
3 |
4 |
|
Labo 11 |
4 |
3 |
119 |
125 |
71 |
74 |
118 |
118 |
39 |
40 |
18 |
21 |
45 |
41 |
89 |
94 |
26 |
38 |
2 |
2 |
|
Labo 14 |
3 |
3 |
129 |
128 |
72 |
72 |
127 |
129 |
58 |
58 |
32 |
29 |
50 |
49 |
102 |
101 |
42 |
41 |
3 |
4 |
|
Labo 15 |
134 |
136 |
76 |
78 |
134 |
136 |
60 |
58 |
39 |
27 |
52 |
61 |
110 |
106 |
51 |
50 |
||||
|
Labo 17 |
3 |
3 |
134 |
132 |
82 |
76 |
136 |
133 |
59 |
50 |
24 |
23 |
46 |
44 |
107 |
105 |
35 |
38 |
0 |
0 |
|
Labo 18 |
5 |
3 |
130 |
129 |
78 |
73 |
133 |
133 |
62 |
59 |
29 |
32 |
58 |
52 |
105 |
105 |
50 |
48 |
2 |
2 |
|
Labo 20 |
1 |
1 |
128 |
131 |
72 |
74 |
130 |
130 |
58 |
56 |
26 |
28 |
48 |
45 |
98 |
93 |
41 |
43 |
0 |
0 |
|
Labo 21 |
0 |
124 |
125 |
69 |
72 |
124 |
126 |
45 |
51 |
19 |
20 |
42 |
42 |
97 |
97 |
35 |
34 |
0 |
1 |
|
Results left blank were rendered non-quantifiable (< limit of quantification).
|
Result removed by the COCHRAN test at 5% |
|
|
Result removed by the GRUBBS test at 5% |
5.2. Total SO2 results
|
Total SO2 (mg/L) |
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
|
No. of laboratories selected |
7 |
12 |
13 |
13 |
8 |
13 |
10 |
13 |
12 |
9 |
|
No. of repetitions |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
|
Min. |
1 |
121.5 |
69.5 |
113 |
53.5 |
19.5 |
42 |
91.5 |
32.5 |
0 |
|
Max. |
3.5 |
135 |
77 |
135 |
61 |
30.5 |
56.5 |
108 |
50.5 |
3.5 |
|
Mean |
2.4 |
128.8 |
73.0 |
128.0 |
58.3 |
24.7 |
47.6 |
100.9 |
40.8 |
1.5 |
|
Standard deviation |
0.93 |
3.63 |
2.20 |
6.24 |
2.42 |
4.04 |
4.89 |
4.61 |
5.80 |
1.35 |
|
Repeatability variance |
0.14 |
1.46 |
3.27 |
2.35 |
1.44 |
3.04 |
2.30 |
3.96 |
2.21 |
0.17 |
|
Inter-laboratory standard deviation |
0.93 |
3.63 |
2.20 |
6.24 |
2.42 |
4.04 |
4.89 |
4.61 |
5.80 |
1.35 |
|
Reproducibility variance |
0.94 |
13.93 |
6.49 |
40.11 |
6.57 |
17.84 |
25.03 |
23.28 |
34.72 |
1.90 |
|
Repeatability standard deviation |
0.38 |
1.21 |
1.81 |
1.53 |
1.20 |
1.74 |
1.52 |
1.99 |
1.49 |
0.41 |
|
r limit |
1.1 |
3.4 |
5.1 |
4.3 |
3.4 |
4.9 |
4.2 |
5.6 |
4.2 |
1.1 |
|
Repeatability %CV (k=2) |
31 |
2 |
5 |
2 |
4 |
14 |
6 |
4 |
7 |
54 |
|
Reproducibility standard deviation |
0.97 |
3.73 |
2.55 |
6.33 |
2.56 |
4.22 |
5.00 |
4.82 |
5.89 |
1.38 |
|
R limit |
2.7 |
10.5 |
7.1 |
17.7 |
7.2 |
11.8 |
14.0 |
13.5 |
16.5 |
3.9 |
|
Reproducibility %CV (k=2) |
80 |
6 |
7 |
10 |
9 |
34 |
21 |
10 |
29 |
184 |
|
Horwitz PRSDR (%) |
14.00 |
7.70 |
8.39 |
7.71 |
8.68 |
9.87 |
8.95 |
7.99 |
9.16 |
15.05 |
|
Horwitz sR |
0.34 |
9.92 |
6.13 |
9.86 |
5.06 |
2.44 |
4.26 |
8.06 |
3.73 |
0.23 |
|
Horwitz R |
0.96 |
28.05 |
17.33 |
27.90 |
14.31 |
6.91 |
12.04 |
22.80 |
10.56 |
0.64 |
|
Horwitz Ratio |
2.82 |
0.37 |
0.41 |
0.64 |
0.50 |
1.71 |
1.16 |
0.59 |
1.56 |
6.04 |
 |
|
Figure 3: Modelling of the repeatability coefficient of variation, %CV(r) (k=2), as a function of concentration, C:
|
 |
|
Figure 4: Modelling of the inter-laboratory reproducibility coefficient of variation, %CVR (k=2), as a function of concentration, C:
|
