Contaminants in Food (Sampling and Analysis Methods)

L.N. 91 of 2005

FOOD SAFETY ACT

(CAP. 449)

Contaminants in Food (Sampling and Analysis Methods)

(Amendment) Regulations, 2005

IN exercise of the powers conferred by article 10 of the Food Safety

Act, the Minister of Health, the Elderly and Community Care has made

the following regulations>

The title of these regulations is the Contaminants in Food Citation.

(Sampling and Analysis Methods) (Amendment) Regulations, 2005,

and they shall be read and construed as one with the Contaminants in

Food (Sampling and Analysis Methods) Regulations, 2004, hereinafter L.N. 488 of 2004.

referred to as “the principal regulations”.

“ELEVENTH SCHEDULE

Methods Of Sampling For Official Control Of The Levels Of Tin In Canned

Foodstuffs

1. Purpose and scope

Samples intended for official checking of the levels of tin in canned foodstuffs shall be

taken according to the methods described below. Aggregate samples thus obtained

shall be considered as representative of the lots.

Compliance with maximum levels laid down in Commission Regulation (EC) No

466#2001 shall be established on the basis of the levels determined in the laboratory

samples.

2. Definitions

Lot> an identifiable quantity of a food commodity delivered at one time and having

been determined by the official to have common characteristics, such as origin, variety,

type of packing, packer, consignor or markings.

Sublot> designated part of a lot in order to apply the sampling method on that designated

part. Each sublot must be physically separate and identifiable.

Incremental sample> a quantity of material taken from a single place in the lot or sublot.

Aggregate sample> the combined total of all the incremental samples taken from the

lot or sublot.

Laboratory sample> sample intended for the laboratory.

3. General provisions

3.1. Personnel

Sampling shall be performed by an authorised person as specified by the Food Safety

Commission.

3.2. Material to be sampled

Each lot which is to be examined must be sampled separately.

3.3. Precautions to be taken

In the course of sampling and preparation of the samples precautions must be taken to

avoid any changes, which would affect the tin content, adversely affect the analytical

determination or make the aggregate samples unrepresentative.

3.4. Incremental samples

As far as possible incremental samples should be taken at various places distributed

throughout the lot or sublot. Departure from this procedure must be recorded in the

record.

3.5. Preparation of the aggregate sample

The aggregate sample is made up by uniting all incremental samples. This aggregate

sample is homogenised in the laboratory.

3.6. Replicate laboratory samples

Replicate laboratory samples for enforcement, trade (defence) and referee purposes

shall be taken from the homogenised aggregate sample unless this conflicts with other

rules on sampling.

3.7. Packaging and transmission of samples

Each sample shall be placed in a clean, inert container offering adequate protection

from contamination and against damage in transit. All necessary precautions shall be

taken to avoid any change in composition of the sample, which might arise during

transportation or storage.

3.8.

Sealing and labelling of samples

Each sample taken for official use shall be sealed at the place of sampling and identified

following procedures established by the Food Safety Commission. A record must be

kept of each sampling, permitting each lot to be identified unambiguously and giving

the date and place of sampling together with any additional information likely to be of

assistance to the analyst.

4. Sampling plans

The sampling method applied shall ensure that the aggregate sample is representative

for the lot that is to be controlled.

4.1. Number of incremental samples

The minimum number of incremental samples to be taken from cans within a lot shall

be as given in Table 1. The incremental samples taken from each can shall be of similar

weight, resulting in an aggregate sample (see point 3.5).

Table 1

Number of cans (incremental samples) which shall be taken to form the

aggregate sample

Number of cans in the lot or sublot

Number of cans to be taken

1 to 25

at least 1 can

26 to100

at least 2 cans

> 100

5 cans

Note that the maximum levels apply to the contents of each can, but for feasibility of

testing it is necessary to use an aggregate sampling approach. If the test result for the

aggregate sample is less than but close to the maximum level and if it is suspected that

individual cans might exceed the maximum level then it might be necessary to conduct

further investigations.

4.2. Sampling at retail stage

Sampling of foodstuffs at the retail stage should be done where possible in accordance

with the above sampling provisions. Where this is not possible, other effective sampling

procedures at retail stage can be used provided that they ensure sufficient

representativeness for the sampled lot.

5. Compliance of the lot or sublot with the specification

The control laboratory shall analyse the laboratory sample for enforcement in at least

two independent analyses, and calculate the mean of the results. The lot is accepted if

the mean does not exceed the respective maximum level (as laid down in Regulation

(EC) No 466#2001) taking into account the measurement uncertainty and correction

for recovery. The lot is non-compliant with the maximum level (as laid down in

Regulation (EC) 466#2001) if the mean exceeds the maximum level beyond reasonable

doubt taking into account the measurement uncertainty and correction for recovery.”.

These regulations implement the provisions of Commission Scope.

Directive 2004#16#EC of the European Community.

“TWELFTH SCHEDULE

Sample Preparation And Criteria For Methods Of Analysis Used In Official

Checking Of The Levels Of Tin In Canned Foodstuffs

1. Precautions and general considerations for tin

The basic requirement is to obtain a representative and homogeneous laboratory sample

without introducing secondary contamination. The analyst should ensure that samples

do not become contaminated during sample preparation. Wherever possible, apparatus

coming into contact with the sample should be made of inert materials e.g. plastics

such as polypropylene, PTFE etc., and these should be acid cleaned to minimise the

risk of contamination. High quality stainless steel can be used for cutting edges. All of

the sample material received by the laboratory is to be used for the preparation of test

material. Only very finely homogenised samples give reproducible results. There are

many satisfactory specific sample preparation procedures which may be used. Those

described in the CEN Standard on the ‘Determination of trace elements — Performance

criteria and general consideration’ have been found to be satisfactory (1) but others

may be equally valid.

2. Treatment of the sample as received in the laboratory

Finely grind (where relevant) and mix thoroughly the complete aggregate sample using

a process that has been demonstrated to achieve complete homogenisation.

3. Subdivision of samples for enforcement and defence purposes

The replicate samples for enforcement, trade (defence) and referee purposes shall be

taken from the homogenised material unless this conflicts with other rules on sampling.

4. Method of analysis to be used by the laboratory and laboratory control

requirements

4.1. Definitions

A number of the most commonly used definitions that the laboratory will be required

to use are given below>

r = Repeatability, the value below which the absolute difference between 2 single test

results obtained under repeatability conditions (i.e., same sample, same operator, same

apparatus, same laboratory, and short interval of time) may be expected to lie within a

specific probability (typically 95 %) and hence r = 2.8 x s r .

s r = Standard deviation, calculated from results generated under repeatability conditions.

RSD r = Relative standard deviation, calculated from results generated under repeatability

conditions [(s r # x ) x 100], where x is the average of results over all laboratories and

samples.

R = Reproducibility, the value below which the absolute difference between single

test results obtained under reproducibility conditions (i.e., on identical material obtained

by operators in different laboratories, using the standardised test method), may be

expected to lie within a certain probability (typically 95 %)< R = 2.8 x s R .

s R = Standard deviation, calculated from results under reproducibility conditions.

RSD R = Relative standard deviation calculated from results generated under

reproducibility conditions [(s R # x ) x 100].

HORRAT r = the observed RSD r divided by the RSD r value estimated from the Horwitz

equation using the assumption r = 0,66R.

HORRAT R = the observed RSD R value divided by the RSD R value calculated from the

Horwitz equation (2).

U = the expanded uncertainty, using a coverage factor of 2 which gives a level of

confidence of approximately 95 %.

4.2. General requirements

Methods of analysis used for food control purposes must comply with the provisions

of items 1 and 2 of the Annex to Council Directive 85#591#EEC of 20 December 1985

concerning the introduction of Community methods of sampling and analysis for the

monitoring of foodstuffs intended for human consumption.

4.3.

Specific requirements

Where no specific methods for the determination of tin in canned foodstuffs are

prescribed at Community level, laboratories may select any validated method provided

the selected method meets the performance criteria indicated in Table 2. The validation

should ideally include a certified reference material.

Table 2

Performance criteria for methods of analysis for tin

Parameter

Value#Comment

Applicability

Foods specified in Regulation (EC) No 242#2004

Detection limit

No more than 5 mg#kg

Limit of quantification

No more than 10 mg#kg

Precision

HORRAT r or HORRAT R values of less than 1,5 in the

validation collaborative trial

Recovery

80 % to 105 % (as indicated in the collaborative trial)

Specificity

Free from matrix or spectral interferences

4.3.1. Performance Criteria — Uncertainty Function Approach

However, an uncertainty approach may also be used to assess the suitability of the

method of analysis to be used by the laboratory. The laboratory may use a method

which will produce results within a maximum standard uncertainty. The maximum

standard uncertainty can be calculated using the following formula>

√ (LOD/2) + (0,1C)

=

Uƒ

where>

Ufis the maximum standard uncertainty

LOD is the limit of detection of the method

C is the concentration of interest

If an analytical method provides results with uncertainty measurements less than the

maximum standard uncertainty, the method will be equally suitable to one which meets

the performance characteristics given in Table 2.

4.4. Recovery calculation and reporting of results

The analytical result is to be reported corrected or uncorrected for recovery. The manner

of reporting and the level of recovery must be reported. The analytical result corrected

for recovery is used for checking compliance (see Annex I, point 5). The analyst should

note the ‘Harmonised Guidelines for the Use of Recovery Information in Analytical

Measurement’ (3) developed under IUPAC#ISO#AOAC. These Guidelines assist when

determining recovery factors. The analytical result has to be reported as x ± U whereby

x is the analytical result and U is the measurement uncertainty.

4.5. Laboratory quality standards

Laboratories must comply with Council Directive 93#99#EEC of 29 October 1993 on

the subject of additional measures concerning the official control of foodstuffs.

4.6. Other considerations for the analysis

Proficiency testing

Participation in appropriate proficiency testing schemes which comply with the

‘International Harmonised Protocol for the Proficiency Testing of (Chemical) Analytical

Laboratories’ (4) developed under the auspices of IUPAC#ISO#AOAC. Some of these

schemes specifically include the determination of tin in foods, and participation in

such a scheme is recommended rather than a general scheme for the determination of

metals in foods.

Internal quality control

Laboratories should be able to demonstrate that they have internal quality control

procedures in place. Examples of these are the ‘ISO#AOAC#IUPAC Guidelines on

Internal Quality Control in Analytical Chemistry Laboratories’ (5).

Sample preparation

Care must be taken to ensure that all the tin in the sample is taken into solution for

analysis. In particular it is recognised that the sample dissolution procedure must be

such that no hydrolysed Sn(IV) species is precipitated (i.e. species such as stannic

oxide SnO 2 , Sn(OH) 4 , SnO 2 .H 2 O). Keep prepared samples in 5 mol#l HCl. However,

SnCl 4 is easily volatilised and so solutions should not be boiled.

REFERENCES

1. MSA EN 13804>2002> Foodstuffs — Determination of trace elements —

Performance criteria, general considerations and sample preparation, CEN, Rue

de Stassart 36, B-1050 Brussels.

2. W Horwitz, ‘Evaluation of Analytical Methods for Regulation of Foods and

Drugs’, Anal. Chem., 1982, 54, 67A — 76A.

3. ISO#AOAC#IUPAC Harmonised Guidelines for the Use of Recovery

Information in Analytical Measurement. Edited Michael Thompson, Steven L

R Ellison, Ales Fajgelj, Paul Willetts and Roger Wood, Pure Appl. Chem.,

1999, 71, 337 — 348.

4. ISO#AOAC#IUPAC International Harmonised Protocol for Proficiency Testing

of (Chemical) Analytical Laboratories, Edited by M Thompson and R Wood,

Pure Appl. Chem., 1993, 65, 2123 — 2144 (Also published in J. AOAC

International, 1993, 76, 926).

5. ISO#AOAC#IUPAC International Harmonised Guidelines for Internal Quality

Control in Analytical Chemistry Laboratories, Edited by M Thompson and R

Wood, Pure Appl. Chem., 1995, 67, 649 — 666.”.

Mitbug[ fl-Istamperija tal-Gvern — Printed at the Government Printing Press

The following shall be added as sub-paragraph (l) of Amends regulation

1 of the principal

subregulation 1.2 of the principal regulations>

regulations.

“(l) Commission Directive 2004#16#EC of 12 February,

2004 laying down the sampling methods and the official methods

of control for the levels of tin in canned foods.”.

Regulation 7.1 of the principal regulations shall be renumbered Renumbers

regulation 7.1 of the

as regulation 8.1 thereof.

principal

regulations.

Immediately after regulation 6 of the principal regulations there Adds new

regulation 7 to the

shall be added the following new regulation>-

principal

regulations.

“Sampling

1 The sampling for the official control of the levels

and analytical

methods for of tin in canned foods shall be carried out in accordance with

Tin in canned

the methods described in the Eleventh Schedule to these

foods.

regulations.

7.2 The sample preparation and methods of analyses

used for the official control of the levels of tin in canned foods

shall comply with the criteria described in the Twelfth

Schedule to these regulations.”.

6. The First Schedule to these regulations is being added as the

Eleventh Schedule to the principal regulations.

7. The Second Schedule to these regulations is added as the

Twelfth Schedule to the principal regulations.