How to choose and instruct a laboratory for chemical food analysis

June 2021

Evaluation of many critical control points for food safety requires evidence from chemical analysis. Regulatory and Technical Managers in the agri-food sector must have near encyclopaedic knowledge of the risks, occurrence likelihood, management, controls and regulation of potential hazards, from allergens and authenticity to zero-tolerance of xenobiotics. On top of that, modern chemical and bio-analytical measurement science is complex and peppered with acronyms.  Molecular biology provides its own puzzles, when does RT-PCR mean Reverse Transcription Polymerase Chain Reaction or Real Time Polymerase Chain Reaction, and what is ddPCR?[1]

Hard-pressed managers inevitably rely on their laboratory to guide them through the correct technique, what the acronyms mean, when it should (or should not) be applied, and what caveats apply to the resulting measurement data. Thus, choosing a laboratory and your relationship with their scientists and technicians will be critical to the successful use of the resulting data. This is especially true for global supply chains, for example, the detection capability (often termed ‘sensitivity, although this has a specific definition – see below) required for analysis for ethanol may differ by at least one order of magnitude between jurisdictions, where alcohol is or is not a socially significant parameter.

This IFST Information Statement has been prepared by a small team of experienced measurement scientists and members of the IFST Scientific Committee. It is pitched at Regulatory and Technical Managers in food businesses. Much of the material will also be of interest if your business has its own in-house laboratory.

There are many technical issues discussed in this document, but it cannot be too heavily stressed that two-way dialogue is central to a productive and satisfactory relationship with your chemical or bio-analytical provider. Both parties must be open to this. You, the customer, must be willing to explain your needs and constraints and listen to the advice of your chosen laboratory. The laboratory must be honest about its capabilities and the limitations, often imposed by scientific rather than commercial considerations, of any of its offerings. 

It is assumed the question of having chemical analysis carried out has been considered, a decision to proceed has been made and the process is now at the stage where concrete plans to choose and instruct a laboratory, or group of laboratories, has been reached.

The choice and instruction of a laboratory for microbiological analysis is discussed in IFST Information Statement: ‘Microbiological Analysis - key considerations

Budget

At an early stage, an indicative budget should be considered. This will need to be checked against the criteria below and it is likely that it will need to be revised, usually upwards.

Sampling

Sampling is crucial for valid data and is dealt with in IFST Information Statement: ‘Sampling for Food Analysis - key considerations


[1] ddPCR – droplet digital polymerase chain reaction

What do you want the lab to do?

It will clearly help to think about what you want the laboratory to do, before approaching any laboratories for quotes and advice. The table below summarises common tasks that require laboratory services and some guidance. As a general principle: have a conversation with the lab, ensure they understand what they are doing and what you are doing.

Table 1: What do you want the laboratory to do and what you should think about?

 

What do you want the laboratory to do?

 

What you should think about

1

Routine testing to a well-developed sampling plan and specified methods for example to provide a Certificate of Analysis (CoA) for onward sale and nutrition claims verification, e.g. low fat, high fibre

There are many analytical service providers offering services.

Choose based on criteria such as:

  • ISO/IEC 17025 accreditation[1]
  • food sector-specific accreditation e.g. CLAS[2]
  • price
  • turnaround time
  • location, logistics
  • performance characteristics, such as LoD/LoQ[3] (see below)

Decisions should be relatively straightforward, with the possible exception of allergen analysis

2

Shelf life assessment and Indication of Minimum Durability (IMD), e.g. ambient, chill, frozen storage as a function of time, and accelerated stability studies

This is a relatively specialist laboratory activity requiring a multidisciplinary approach[4], including microbiological assessment (pathogens and spoilage organisms, including yeasts and moulds), but also chemical (e.g. rancidity, moisture, water activity, preservatives, and labile compounds such as vitamins), physical and sensory analysis

 

3

Non-routine investigational work, such as:

  • series of consumer complaints
  • taint problem
  • health claim dossier
  •  novel food dossier
  • new product development (NPD)
  • method development and validation, for a new product or process
  • technical challenge e.g. a new market with a different ambient climate
  • product recall
  • challenged by an authority, competitor or a customer, alleging an allergen, contaminant, additive, or they have an analyte found in a finished product and implicate your ingredient 
  • competitor product analysis
  • look-see testing e.g. authenticity

This requires more care in choosing a laboratory. Considerations, in addition to those above, include:

  • expertise
  • scope of accreditation. It may be difficult in some instances to find a laboratory with specific accreditation, but familiarity with the topic and flexible scope accreditation should be sought
  • which accreditation/regulatory system is appropriate e.g. ISO/IEC 17025, GLP[5] or GMP[6]
  • equipment
  • capacity
  • experience
  • understands the context

N.B. these are dealt with in more detail below

4

Any combination or all of the above

Apply appropriate selection of above criteria

 


[1] A useful starting point is ILAC, the international organisation for accreditation bodies involved in the accreditation of calibration or testing laboratories (using ISO/IEC 17025), inspection bodies (using ISO/IEC 17020), proficiency testing providers (using ISO/IEC 17043), reference material producers (using ISO 17034), medical testing laboratories (using ISO 15189), inspection bodies (using ISO/IEC 17020), proficiency testing providers (using ISO/IEC 17043) and reference material producers (using ISO 17034), https://ilac.org/about-ilac/

[2] CLAS, the Campden Laboratory Accreditation Scheme

[3] LoD and LoQ limits of detection or quantification, should be agreed concentrations an appropriate interval below any upper limit applied to the parameter by law or specification

[4] See, for example, Kilcast, D. and Subramaniam, P. eds., 2000: The stability and shelf-life of food, Woodhead Publishing Ltd., Cambridge, UK

[5] GLP, Good Laboratory Practice, see this for example - this is likely to be relevant to sectors such as food supplements, or foods for special medical purposes, or if seeking authorisation for health claims and you require studies to support the dossier.

[6] GMP, Good Manufacturing Practice, may be applicable if you are testing foods that overlap with healthcare regulation (e.g. supplements) and you are acceptance-testing against specifications rather than conducting a study to support authorisation dossiers.

Multiple tests

You will often require multiple tests (e.g. microbiology and allergens, nutritional parameters and a range of chemical tests) on the same sample or set of samples. Is it better to take one sample and test it multiple times, or multiple samples - one for each test?

Some common considerations:

i) microbiology should be done first, as subsampling will be to the required aseptic procedures in a microbiology laboratory, but not necessarily in a chemistry laboratory

ii) if you are interested in particulate contaminants or allergens, please make this clear. Sample homogenisation is routine and essential but destroys any information on particulate distribution.

A ‘one stop shop’ laboratory that accepts one sample for triage, and distribution to the required departments, or locations for analysis may be the answer. However, you should be made aware of exactly what happens to your sample.

You may well find yourself having to source more obscure testing yourself.

Laboratory attributes

The performance of official control laboratories is controlled by Regulation 2017/625 on official controls. While possibly more exacting that for a low-cost high throughput commercial laboratory the requirements set out in this regulation are a useful place to start.

These requirements are that the laboratory should have:

  1. The expertise, equipment and infrastructure required to carry out analyses or tests

Accreditation, which requires participation in appropriate proficiency test rounds is a good indication of expertise. Check that the required equipment and space to carry out the claimed workload is available. Some applications (e.g. quick turn-round suites of pesticides analyses for ≥300 analytes, GMOs by PCR or allergens by LC-MS/MS) may require the detection capability provided by relatively recent versions of high-end instrumentation. Check that the scope of the method particularly multi-residue methods (e.g. pesticides and veterinary residues) includes the specific substances you are interested in. Check if the instrumentation continues to be supported by its supplier or manufacturer. On the other hand, robust well-maintained triple quadruple Mass Spectrometry (MS) instruments provide useful performance over a span of at least 10 years. A laboratory information management system is generally required. Consider if the scope of work the laboratory undertakes is compatible with your needs. As an example, if the laboratory specialises in trace metals analysis at low (μg/kg[1]) levels, and you send them a pre-mix sample containing 10% metals, then your sample will cross-contaminate their equipment.

  1. Sufficient number of suitably qualified, trained and experienced staff

You can assume from ISO17025 accreditation that staff are suitably trained, however, you should assure yourself that the laboratory has sufficient competent staff to deliver your requirements, regardless of their competing priorities, and has adequate contingency and succession planning. Chartered Scientist (CSci) and Registered Scientist (RSci) status is awarded under license from the Science Council by IFST, for example, see this matrix.

Note that, unless separately listed, ISO17025 accreditation specifically excludes opinions and interpretations as it applies only to the factual test results.  Laboratories are not permitted to put interpretations on the CoA.  If you want your laboratory to explain the context of results to you, then it is important to look for scientists, or Key Account Managers, who are not only technically competent but also good communicators.

  1. Performs impartially and free from any conflict of interest

Look for evidence of commitment at a senior level, such as Board and Managing Director.

  1. Can deliver in a timely manner

Decide on your requirements in terms of product recall (safety), marketing timescale, new product launch, when you really need it, add in time for transit and to discuss results, processing data and making sense of it. Integrate your critical deadlines with those of the laboratory and discuss with them. Remember that analytical runs must include quality control (QC) samples (including replicates, controls, blanks) and a minimum number of billable samples (typically 10, as a minimum) must be in the run for it to be financially viable. Thus, an urgent ‘one-off’ will usually be more expensive. Laboratories often have a routine cost and a fast track cost. Owing to the required analytical protocol, e.g. stipulation of overnight hydrolysis to release the analyte of interest, methods may have a minimum time of completion. Quality control assessment of a run is essential and adds time. Laboratories often have, and should have, delegated levels of authority to release results, which may add to the time taken to report.

  1. Operates in accordance with ISO/IEC 17025 standard and is accredited in accordance with that standard, by a national accreditation body

As noted above, ISO/IEC 17025 accreditation[2], or GLP[3] is a key attribute. The scope of the accreditation should include both your sample type and the proposed test method(s), although you may need to ask the laboratory for advice on this. The laboratory may have a flexible scope of accreditation which covers a group of related methods and, with certain conditions, may be applied to an analyte/matrix combination for which the laboratory does not hold specific accreditation.

You may need a test for which the lab has a method/protocol for but do not have accreditation. The Quality System in place must still cover such work and you might seek an assurance that this is so. Moreover, the lab should be able to demonstrate the method is validated and has acceptable performance characteristics.  You may wish to check the reason why a lab chooses to withdraw a method from the scope of accreditation as they may have been in danger of losing it owing to deficits in performance. Note however that since accreditation is a significant overhead withdrawal may have been solely for commercial reasons. Even if unaccredited the results must be properly reported.

A glance at the table of contents of ISO/IEC 17025:2017(en) ‘General requirements for the competence of testing and calibration laboratories’[4] shows that most of the aspects addressed in this IS are covered by this laboratory standard. These include impartiality and confidentiality, resource requirements (personnel, equipment and ‘subcontracting’), process requirements including contract review, selection of methods, sampling, sample handling, records, the method performance characteristics (see below), reporting results, handling complaints, the quality management system itself, and metrological traceability.

A key requirement of ISO/IEC 17025 is that laboratories communicate with you in advance, to agree on how they will account for measurement uncertainty when giving a compliance decision against any limit or specification.  This topic is covered in IFST Information Statement: ‘How to Interpret Laboratory Results

The international organisation for accreditation bodies is ILAC. The UK accreditation body is UKAS[5].  You can search for a lab that carried the required UKAS accreditation here. Other national accreditation bodies have similar searchable databases.

Campden Laboratory Accreditation Scheme (CLAS) is an independent laboratory accreditation scheme, for food industry laboratories, established specifically to meet the need for a recognised standard for food, drink and allied laboratories[6].  It is a less detailed standard than ISO17025, with consequentially lower overheads. It is particularly suitable for in-house laboratories, where you do not need international mutual acceptance of results, but still want an external stamp of approval.

 


[1] Microgram per kilogram, μg/kg, parts per billion

[2] A useful starting point is ILAC, the international organisation for accreditation bodies involved in the accreditation of calibration or testing laboratories (using ISO/IEC 17025), inspection bodies (using ISO/IEC 17020), proficiency testing providers (using ISO/IEC 17043), reference material producers (using ISO 17034) and, medical testing laboratories (using ISO 15189), inspection bodies (using ISO/IEC 17020), proficiency testing providers (using ISO/IEC 17043) and reference material producers (using ISO 17034), https://ilac.org/about-ilac/

[3] GLP, Good Laboratory Practice, see this for example 

[4] ISO/IEC 17025:2017(en) General requirements for the competence of testing and calibration laboratories (Accessed 14th November 2020)

Is the method fit for purpose?

There are a number of performance characteristics that can be used to assess if a method is fit for purpose.

For example (see Appendix 1):

  • accuracy (trueness and precision, also termed ‘bias’)
  • applicability (matrix and concentration range)
  • limit of detection
  • limit of quantification
  • precision (repeatability and reproducibility)
  • selectivity
  • sensitivity
  • linearity
  • uncertainty

Your laboratory must conduct a method validation study to assess these (called ‘verification’ if they are importing a method already validated elsewhere). This is a significant overhead for laboratories and the reason that they may not be able to accept all types of sample for testing.

Measurement uncertainty

Chemical and bio-analytical results cannot be perfect; this should not come as a big surprise. We use the term measurement uncertainty to describe this lack of perfection[1].

Thus, in the reporting of results (in certificates of analysis and in scientific papers) an expression of the following form can be found:

Result of analysis:

Parameter name (e.g. Aflatoxin B1) … x ± y followed by a unit

This is the mean ± the uncertainty.

Measurement uncertainty includes both random and systematic effects (see Appendix 1). If there are significant known biases, then the laboratory can adapt the method to try and remove or reduce them. However, there will always be systematic effects present including, for example, in relation to the calibration of equipment, and tolerances associated with glassware.

The standard uncertainty (u) represents about 68 % of the possible spread of results in a ‘normal’ (Gaussian) distribution, as in the familiar ‘bell-shaped curve’. Laboratories usually report the expanded uncertainty where ‘u’ is multiplied by a ‘coverage factor’[2]k’.  This is typically set as equal to 2, which gives an expanded uncertainty representing over 95% of the possible spread of results. Best practice for laboratories is to include expanded uncertainties on their certificates of analysis, and these should be accompanied by a statement of the level of confidence and the coverage factor used. However, in practice, laboratories may report in a number of ways. The uncertainty can be a standard deviation ‘s’, the standard uncertainty ‘u’, or the expanded measurement uncertainty ‘U’.   It is important that you understand which they use. The practical implications of this are:

  • if you want to know the uncertainty, you may need to ask the laboratory to state the measurement uncertainty as it may not be routinely reported
  • if you want to understand the uncertainty, you will need to check with the laboratory which of the above measures has been reported: standard deviation (s), standard uncertainty (u), or expanded measurement uncertainty (U)
  • if you want to compare results from different laboratories, or from different methods of analysis, you can only do so with a knowledge of the measurement uncertainty
  • the lower, or occasionally the upper, bound of the measurement uncertainty may be the datum of interest to establish whether the result is compliant or otherwise.

[2] A statistically valid coverage factor can be calculated from a reasonable dataset of results however it is often assumed that for most practical purposes a value of 2 is reasonable.

Why measurement uncertainty is important: assessing compliance

The way your laboratory treats measurement uncertainty is critical to how they assess a result’s compliance against a limit or specification. A well-known graphical representation of various compliance scenarios is shown in Figure 1[1].

Figure 1. Possible results (A to D) and their expanded measurement uncertainties against a permitted upper limit (dotted line); y-axis is the concentration (arbitrary units)

Result ‘A’ is above the arbitrary limit (of 5) beyond a reasonable doubt, as the lower bound of its expanded measurement uncertainty is above the limit. For result ‘B’, although the mean is above the limit, it cannot be demonstrated that the product is non-compliant (above the limit) to the criminal burden of proof (beyond reasonable doubt) since it is possible that the ‘true’ value, within the confidence interval, lies below the limit. Result ‘C’ is more reassuring, in most instances, as the mean is below the limit, however again, pause for thought is required. Only result ‘D’, for which the probability of non-compliance is low, is comfortably reassuring.  If you want your laboratory to use a particular one of these approaches, on their ‘Certificates of Analysis’, then it is important that you communicate this to them. 

If your laboratory is accredited to ISO 17025 then they are obliged to agree to their approach with you in advance, and also to explicitly state it in the report.  This is covered in the Decision Rules section of IFST Information Statement: ‘How to Interpret Laboratory Results 


[1] Redrawn from an original idea by S L R Ellison, National. Measurement Laboratory (NML), LGC

Why measurement uncertainty is important: comparing results

When a sample is re-tested, it often prompts the question ‘why are the two results different?’ or even, ‘are the two results different?’.

There are statistical procedures to assess whether two results are comparable. Chapters on tests of significance and ‘the null hypothesis' can be consulted in standard works (see above). For the purposes of this Information Statement, however, a simple approach by inspection is probably sufficient. Illustrated graphically in Figure 2 for four results for equivalent samples.

Figure 2: Four results for equivalent samples; the y axis is arbitrary concentration units

If it can be assumed that the samples were truly equivalent, as per the responsibility of the sampler, and results ‘A’ and ‘B’ can be considered comparable since their error bars overlap. Result ‘C’ differs sufficiently from either ‘A’, ‘B’ or ‘D’, to warrant further investigation. Result ‘D’ overlaps ‘A’ and ‘B’, however, its measurement uncertainty is larger, and it may be suboptimal compared to them for that reason.

Other considerations

Outside of routine analyses, well understood by you the customer, it may be necessary to explore the degree to which your chemical and bio-analytical service laboratory understands the context of what they are doing for you so that they can properly advise you, and offer a valid interpretation of results. Examples are given below.

Scientific, legislative, or policy context
  • Allergen analysis requires your laboratory to be aware of the scientific, legislative and policy context of your testing
  • Analysis for dietary fibre can be carried out by two different methods (AOAC or Englyst). It is important for both you and your laboratory to be aware of the science behind each, to ensure the appropriate one is used. See IFST Information Statement: ‘Dietary Fibre. More generally, for empirical methods such as for dietary fibre or fat, the resulting data are defined by the method
  • Some legislation on contaminants contains decision rules, for example the experimental data must be corrected for recovery and assessment against the upper limits must take into account measurement uncertainty
  • Sampling procedures for mycotoxins often incorporate high shear mixing with water to ensure adequate homogenisation. The results must be corrected back to the original commodity by factoring in the amount of water added during the homogenisation process
  • There are no current maximum limits for acrylamide in food, but there are benchmark concentrations for various foods. However, these are not legal maximum limits, nor safety levels, and should be used by food business operators (FBOs) to monitor the effectiveness of relevant measures, to ensure levels of acrylamide in their products are as low as reasonably achievable.

Awareness of context is expensive as it requires the retention of experienced personnel by the laboratory.  Customers of chemical and bio-analytical service provision must carefully weigh up the cost benefits, bearing in mind that ‘context awareness’ overhead may either appear in the cost per test, or in a separate ‘consultancy’ fee structure.

Sampling, sample handling, transport and treatment

Flawed sampling wastes time and money, both in the sampling and subsequent analysis. Laboratories should be able to, and usually can give advice on sampling, sample handling (e.g. containers, storage temperatures), and the correct order of subsampling, if multiple tests are required. See IFST Information Statement ‘Sampling for Food Analysis - key considerations’. The location of your laboratory, how best to package and transport the samples (so they arrive in a condition to validly test), and whether or not they have a logistics arrangement to pick up samples may be important. A record of the chain of custody of the sample may be necessary if subsequent legal proceedings or litigation is in prospect.  

Miscellaneous

You should probably discuss the following with a prospective chemical and bio-analytical service provider:

  • tests and methods that are applicable, and available, and expect honesty about laboratory capabilities
  • willingness to enter into a consortium when one laboratory cannot offer all the testing you require
  • availability and cost of an emergency and/or out of hours response from the laboratory
  • agreed policy on sample retention, and the creation of a library of retained samples
  • agreed reporting format, availability of an online sample registration and reporting portal, and the details in the report e.g. International Units (IU) versus mg/kg 
  • agreed conversion factors, e.g. Nitrogen factors to convert from Dumas, or Kjeldahl nitrogen results, to total protein, or from nitrogen to meat content
  • sampling patterns - these should be considered and agreed upon by both parties. An unexpected influx of samples may induce mistakes in the laboratory and a backlog of work leading to increased turnaround times.

You may also wish to consider:

  • whether you submit blind duplicates of your samples to assess laboratory performance (how to interpret - see above). If so, its probably best to discuss with the laboratory to understand and agree measurement uncertainty, so as to properly assess legitimate differences in the results of blind duplicates. It is also common practice, e.g. in contaminated land investigation, to send equivalent samples to several laboratories and compare the results. Again, it is important to understand measurement uncertainty 
  • that your destination market may have differing needs and culture, for example priority allergens differ according to global region, legislation and hence limits differ and cultural norms that may influence reporting of results, and attitudes to dialogue and transparency may differ. If in doubt seek in-country advice
  • in general, although ISO/IEC 17025 accreditation is designed to reduce the need for individual audit, think about visiting the laboratory and carrying out your own audit, especially if the data generated are crucial to your product or process
  • what will happen if the laboratory uncovers a problem with your product, e.g. excess mycotoxins, undeclared allergens, as a consequence of what analyses you have requested. It is your responsibility to deal with unsafe or mislabelled food. There is a legal obligation to report it to the competent authority, i.e. in UK, your Local Authority and/or the Food Standards Agency (FSA) if the food has entered the supply chain. If the food remains within your control, and is effectively quarantined, you do not need to report anything. The laboratory may wish to make clear they have no responsibilities beyond reporting to you and leaving it to you to deal with. However, some laboratories may want to ensure they do not become ‘tainted’ by association with a food business that abrogates their responsibilities. Either way, you may see these aspects covered in the laboratory’s terms and conditions, under which it trades. Similarly, if the laboratory finds something you did not ask them to analyse for, e.g. a pesticides suite goes beyond what you instructed, some prior thought and discussion may ultimately be useful.
Official Control laboratories

In the EU and UK, official food laboratories are ‘Public Analysts’ and ‘Food Examiners’ (microbiology laboratories) that undertake work for local authorities in support of enforcement of food standards and food safety. Other designated laboratories undertake official controls in specified areas. All official laboratories must employ staff who have qualifications defined by national legislation.  In addition to be named an official control laboratory, laboratories must have a ‘Public Analyst’, formally appointed by a local authority, or a qualified ‘Food Examiner’.

In the UK, the Food Standards Agency (FSA) and Food Standards Scotland (FSS) are responsible for appointing[1] the majority of official food control laboratories. FSA and FSS do not own or operate any of these laboratories. Some are private sector organisations, and some are owned and operated by Local Authorities. Many carry out commercial work in addition to their official duties. There are statutory requirements for qualifications and experience, infrastructure, accreditation and avoidance of conflict of interest[2],[3].

 


[2] The Food Safety (Sampling and Qualifications) (England) Regulations 2013 with devolved equivalents

[3] Regulation (EU) 2017/625 of the European Parliament and of the Council of 15 March 2017 on official controls, Article 37

Special cases

Allergens: 'IFST Information Statement on Allergens'

Authenticity: Centres of expertise in Food Authenticity Network (FAN); including http://www.foodauthenticity.global/training

Dietary Fibre:  'IFST Information Statement on Dietary Fibre' 

DNA (PCR) - Centres of expertise in Food Authenticity Network (FAN) and ‘DNA Techniques to Verify Food Authenticity: Applications in Food Fraud’, Eds. Malcolm Burns, Lucy Foster, Michael Walker, Royal Society of Chemistry (RSC), London 2019, ISBN 978-1-78801-178-5, pp xvii + 325, https://doi.org/10.1039/9781788016025

Microbiology: ‘IFST Information Statement on Microbiological Analysis - key considerations’;

Microscopy: IFST Information statement on Physical Analysis - key considerations’;

Nitrogen factors (conversion of total nitrogen by Kjeldahl or Dumas to protein and meat content) see:

  • ‘Nitrogen factors as a proxy for the quantitative estimation of high value flesh foods in compound products, a review and recommendations for future work’, D. Thorburn Burns, M Walker, S. Elahi and P. Colwell, Anal. Methods, 2011, 3, 1929,
  • ‘Successive Nitrogen factors’ Technical Briefs in the RSC Analytical Methods Committee Technical Briefs website https://www.rsc.org/Membership/Networking/InterestGroups/Analytical/AMC/TechnicalBriefs.asp 
  • B. McClean, ‘Meat and meat products: the calculation of meat content, added water and connective tissue content from analytical data’, Campden and Chorleywood Food Research Association, Chipping Campden, 2007.
Non-targeted analysis

Non-targeted analysis (NTA) reports previously unknown or poorly studied compounds, for example by liquid chromatography-tandem mass spectrometry datasets of isotopic masses, retention times, or predicted molecular formulae. NTA is particularly useful to explore non intentionally added substances and although conventional validation studies are difficult, should be attempted[1].

 


[1] Sobus et al., 2018. Integrating tools for non-targeted analysis research and chemical safety evaluations at the US EPA. Journal of exposure science & environmental epidemiology, 28(5), 411-426.

Pesticides analysis

Specialist analytical service providers are available for suites of over 300 pesticides residues in rapid turnout times. See this. For guidance on pesticides and plant protection products, maximum residue limits databases and authorisation. In particular there is a series of guidance documents on pesticides analysis.

Vitamin analysis

Vitamins analysis is often a specialist activity and an experienced accredited laboratory is to be preferred.

Acknowledgements

M Walker’s contribution to this document was supported by the BEIS Government Chemist Programme in LGC. Vicki Barwick is thanked for valuable comments on the draft.

Institute of Food Science & Technology has authorised the publication of the following Information Statement on How to Choose & Instruct a Laboratory for Chemical Food Analysis.

This updated Information Statement has been prepared by Dr Michael Walker FIFST, peer-reviewed by professional members of IFST and approved by the IFST Scientific Committee. 

This information statement is dated June 2021. 

The Institute takes every possible care in compiling, preparing and issuing the information contained in IFST Information Statements, but can accept no liability whatsoever in connection with them. Nothing in them should be construed as absolving anyone from complying with legal requirements. They are provided for general information and guidance and to express expert professional interpretation and opinion, on important food-related issues.