Official Control Laboratories Research Articles

Food Adulteration in Switzerland: From 'Ravioli' over 'Springbok' to 'Disco Sushi'.

The driving force behind food adulteration is monetary profit and this has remained unchanged for at least the last hundred years. Food adulterations were and still are difficult to uncover because they occur mostly in an unpredictable and unexpected way. Very often food falsifiers take advantage of modern technology in such a way that food adulterations are difficult or sometimes even impossible to detect. Targets for food adulteration were and still are highly priced food items such as spirits, meat, seafood and olive oil. Although difficult to detect, food adulterations were in the past strong driving forces for the development of adequate detection methods in the official food control laboratories and for the enforcement of the food law. A very prominent example in this context is the 'Ravioli scandal' in Switzerland in the late 1970s which showed that cheap second-class meat could be processed into products without being discovered for long time. As a consequence the official food control laboratories in Switzerland were reinforced with more laboratory equipment and technical staff. With the introduction of new detection principles such as DNA-based analytical methods new kinds of food adulteration could and can be uncovered. Analytical methods have their limits and in some cases of food fraud there are no analytical means to detect them. In such cases the examination of trade by checking of accounts is the method of choice.

A significantly lower potency observed for the 3rd WHO International Standard for Parvovirus B19V DNA with the cobas TaqScreen DPX test.

In the context of the Official Medicines Control Laboratories plasma pool testing for Parvovirus B19 DNA, we use the cobas TaqScreen DPX test. When we re-evaluated this method using the 3rd B19 DNA WHO IS at the final concentration of 4 log IU/mL, we observed a titre lower than expected, i.e. 3.79 log IU/mL. Therefore, we further investigated the accuracy of the DPX test. The following B19V DNA materials were tested by using both the DPX test and an in-house real-time PCR: The 1st, 2nd and 3rd WHO ISs for B19V DNA The Non WHO B19V DNA Reference Material for NAT The Biological Reference Preparation B19 virus DNA for NAT testing, batch 1 . The DPX test showed a good accuracy for all B19V DNA materials with the exception of the 3rd WHO IS for B19V DNA. In fact, an underestimation of about 38% was observed for all dilutions of this standard with respect to the nominal titre. With the B19V in-house real-time PCR, all four materials proved to be well calibrated against the 1(st) WHO IS for B19V DNA, used as external standard curve. In this study, we demonstrated that the DPX test underestimates the B19V DNA content of the 3rd WHO IS for B19V DNA and that this is not due to an incorrect potency assigned to the standard but, most probably, to a mismatch between the primers/probe and the sequence of the target region in the 3rd WHO IS for B19V DNA.

The occurrence of Salmonella in raw and ready-to-eat bean sprouts and sprouted seeds on retail sale in England and Northern Ireland.

A total of 554 samples of bean sprouts or other sprouted seeds were collected at retail sale and submitted to nine Official Control Laboratories in England and Northern Ireland during January to March 2011. Samples (100g) were tested for the presence of Salmonella using the EN ISO 6579:2002 method. Products labelled as ready-to-eat comprised 23% of the samples and 61% were labelled as raw or to-cook: the remaining 12% had no indication if the food was intended as ready-to-eat or ready-to-cook, and 4% were not recorded. Salmonella spp. were detected from four samples of mung-bean sprouts (0·7% of all the 554 samples) and all four isolates were confirmed as Salmonella enterica serovar Abaetetuba (11:k:1,5). Two of the samples where Salmonella was detected were sold as ready-to-eat (labelled 'rinse and serve' only): The remaining two were from samples labelled as ready-to-cook. Consumption of sprouted seeds have been associated with infections from a range of foodborne pathogens, particularly Salmonella and shigatoxin producing Escherichia coli (STEC). However, there is limited data (including that from EU monitoring) on foodborne pathogens in samples of this food type which are not associated with outbreaks of infection. Out of 554 raw and ready-to-eat bean sprouts and sprouted seeds sampled at retail, Salmonella spp. was detected from four samples. This study illustrated the potential of this product to be contaminated with a human pathogen and the importance of considering the intended use and preparation of specific food in assessing microbiological risks.

Meta-audit of laboratory ISO accreditation inspections: measuring the old emperor's clothes.

Accreditation to ISO/IEC 17025 is required for EC official food control and veterinary laboratories by Regulation (EC) No. 882/2004. Measurements in hospital laboratories and clinics are increasingly accredited to ISO/IEC 15189. Both of these management standards arose from command and control military standards for factory inspection during World War II. They rely on auditing of compliance and have not been validated internally as assessment bodies require of those they accredit. Neither have they been validated to criteria outside their own ideology such as the Cochrane principles of evidence-based medicine which might establish whether any benefit exceeds their cost. We undertook a retrospective meta-audit over 14 years of internal and external laboratory audits that checked compliance with ISO 17025 in a public health laboratory. Most noncompliances arose solely from clauses in the standard and would not affect users. No effect was likely from 91% of these. Fewer than 1% of noncompliances were likely to have consequences for the validity of results or quality of service. The ISO system of compliance auditing has the performance characteristics of a poor screening test. It adds substantially to costs and generates more noise (false positives) than informative signal. Ethical use of resources indicates that management standards should not be used unless proven to deliver the efficacy, effectiveness, and value required of modern healthcare interventions.

Proficiency testing in food control: an evaluation of more than 13 years

According to article 32 and 33 of Regulation (EC) No 882/2004, the European Union and National Reference Laboratory for pharmacologically active substances (EURL/NRL) at the Federal Office of Consumer Protection and Food Safety (BVL) is responsible, among other tasks, to support official control laboratories and as competent authorities on a national and EU level. The EURL has used in-house reference materials with residues of β-agonists, coccidiostats, nitroimidazoles, anthelmintics and NSAIDs from animal studies for proficiency testings (PT) for more than 13 years. The presentation provides a detailed picture of how to evaluate PTs for the determination of veterinary drugs. Proficiency testings are evaluated according to the prescriptions of ISO/IEC 17043, ISO 13528 and DIN 38402-45, using the statistical software package “ProLab Plus 2014” (QuoData GmbH in Dresden, Germany). The presentation illustrates the statistical parameters for: (a) Single analyte concentration (robust estimation of assigned value (HAMPEL), reproducibility standard deviation (Q-method) and scoring of laboratory results, (b) Graphical methods for combining performance scores (z-scores overview, combination scores and Mandels-h statistics), (c) Graphical methods for monitoring performance over years (control charts for z-scores and combination scores). In view of false negative results, it was regarded as not sufficient to include only the z-scores and combination scores for the assessment of the laboratories proficiency. Therefore a modified combination score was established that accounts for the overall evaluation of the examination results as well as for the false negative (n. a.—not analysed and n. f.—not found) examination results.

Proficiency tests on olive oil organized by the Italian National Reference Laboratory for pesticides: long-term performance of laboratories

The Italian National Reference Laboratory (NRL) for pesticides in Food of Animal Origin and Commodities with High Fat Content yearly organizes proficiency tests (PTs) on olive oil, addressed to: Mediterranean laboratories of International Olive Council, European laboratories (NRLs, official control laboratories and private laboratories), involved in the national and European monitoring programs. The main aim of these PTs was to compare the performances of the laboratories in Mediterranean and European countries in order to promote mutual acceptance of pesticide residue data regarding the analytical controls of olive oil. Since 2011, the protocol of the last three PTs has not been changed and also the list of participants has been steady, in the range of 40–44 laboratories. The test material consisted of commercial olive oil spiked with six different pesticides chosen in each exercise from a possible list of 25–26 compounds. In particular, the pesticide residues selected in our PTs are mainly those considered in the official control plans, with spiked mass fraction levels around their reference values set in the European Regulations. Pertinent and detailed information regarding multi-residue methods has been demanded to all participants, and an overall evaluation by means of a combined index of performance, such as the sum of the weighted z-scores, SWZ, and the sum of squared z-scores, SZ2, has been performed. This type of exercise provides the possibility for the laboratories to control and improve the performance of their analytical methods employed during the official control on more parameters over the years. In this paper, a comparison of the overall performance of the laboratories was shown by using the SWZ or SZ2 indexes, giving significance to the Italian participants as required by the NRL aim. During the three investigated COIPTs, 91 % of the laboratories obtained satisfactory results with SWZ or SZ2 not exceeding 3. Focusing on the results of Italian laboratories, the performance improved during the selected PTs, respectively, from 70 % to 100 %. Moreover, the effect of the analytical methods on the dispersion of the results was evaluated in order to review the long-term performance of the participants.

The Monitoring of Triphenylmethane Dyes in Aquaculture Products Through the European Union Network of Official Control Laboratories.

Aquaculture has been the fastest growing animal production industry for the past four decades, and almost half of the fish eaten in the world are now farmed fish. To prevent diseases in this more intensive aquaculture farming, use of therapeutic chemicals has become a basic choice. The monitoring of malachite green, a triphenylmethane dye and one of the oldest and widely used chemicals in fish production, has gained more interest since the mid 1990s when this substance was finally proven to be toxic enough to be prohibited in seafood products destined for human consumption. The enforcement of the European Union (EU) regulation of this banned substance along with some other triphenylmethane dye congeners and their metabolites in its domestic production and in seafood imports was undertaken through the National Residue Monitoring Plans implemented in nearly all of the 28 EU member states. The reliability of the overall European monitoring of this dye contamination in aquaculture products was assessed by using the results of proficiency testing (PT) studies provided by the EU Reference Laboratory (EU-RL) in charge of the network of the EU National Reference Laboratories (NRLs). The proficiency of each NRL providing analytical support services for regulating dye residues was carefully checked during three PT rounds. In the process, the analytical methods developed and validated for this purpose have gradually been improved and extended over the last two decades.

PT as a tool to point out criticalities in the strategy for control of antibiotic residues in milk: the Italian experience

Screening represents the first step for antibiotic residues control; thus, screening methods play a key role in the entire control procedure. The Italian National Reference Laboratory (NRL) for veterinary antimicrobial residues in food from animal origin organized the first proficiency test (PT) for the screening of antibiotic residues in milk to assess the competence of the official control laboratories. The 38 participants received two series (respectively, at 1.8 % and 3.5 % of fat mass fraction) of eight blind lyophilized milk samples, spiked with cloxacillin (CLX), benzylpenicillin (PEN), sulfadiazine (SDZ) and oxytetracycline (OXY) at once and twice the respective maximum residue limit. In addition, an unspiked sample (blank) was also included in each series. Since the vast majority of false-negative results was associated with OXY, leading to low sensitivity and accuracy, laboratories performances were evaluated separately for OXY (sensitivity 16.44 %, false-negative rate 62.25 % and accuracy 44.54 %) and, respectively, for CLX, PEN and SDZ assessed together (sensitivity 99.56 %, false-negative rate 2.53 % and accuracy 99.63 %); the false-positive rate resulted equivalent to 0 % and the specificity to 100 %. The criticality identified by the PT was that OXY was not detectable under the routine screening analysis conditions adopted because of the use of only two screening methods (Delvotest SP-NT and CMT) both unfit for its detection at mass fractions of interest. As a consequence, the NRL provided guidance to participants to implement different and complementary screening methods. The effectiveness of the corrective actions undertaken by participants will be evaluated with the next PT.

Analysis of illegal peptide biopharmaceuticals frequently encountered by controlling agencies

Recent advances in genomics, recombinant expression technologies and peptide synthesis have led to an increased development of protein and peptide therapeutics. Unfortunately this goes hand in hand with a growing market of counterfeit and illegal biopharmaceuticals, including substances that are still under pre-clinical and clinical development. These counterfeit and illegal protein and peptide substances could imply severe health threats as has been demonstrated by numerous case reports. The Belgian Federal Agency for Medicines and Health Products (FAMHP) and customs are striving, together with their global counterparts, to curtail the trafficking and distributions of these substances. At their request, suspected protein and peptide preparations are analysed in our Official Medicines Control Laboratory (OMCL). It stands to reason that a general screening method would be beneficiary in the battle against counterfeit and illegal peptide drugs. In this paper we present such general screening method employing liquid chromatography–tandem mass spectrometry (LC–MS/MS) for the identification of counterfeit and illegal injectable peptide preparations, extended with a subsequent quantification method using ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD). The screening method, taking only 30min, is able to selectively detect 25 different peptides and incorporates the proposed minimum of five identification points (IP) as has been recommended for sports drug testing applications. The group of peptides represent substances which have already been detected in illegal and counterfeit products seized by different European countries as well as some biopharmaceutical peptides which have not been confiscated yet by the controlling agencies, but are already being used according to the many internet users forums. Additionally, we also show that when applying the same LC gradient, it is also possible to quantify these peptides without the need for derivatization or the use of expensive labelled peptides. This quantification method was successfully validated for a representative subset of 10 different peptides by using the "total error" approach in accordance with the validation requirements of ISO-17025.

Batch release of immunoglobulin and monoclonal antibody products

The Paul-Ehrlich Institute (PEI) is an independent institution of the Federal Republic of Germany responsible for performing official experimental batch testing of sera. The institute decides about the release of each batch and performs experimental research in the field. The experimental quality control ensures the potency of the product and also the absence of harmful impurities. For release of an immunoglobulin batch the marketing authorization holder has to submit the documentation of the manufacture and the results of quality control measures together with samples of the batch to the PEI. Experimental testing is performed according to the approved specifications regarding the efficacy and safety. Since implementation of the 15th German drug law amendment, the source of antibody is not defined anymore. According to §32 German drug law, all batches of sera need to be released by an official control laboratory. Sera are medicinal products, which contain antibodies, antibody fragments or fusion proteins with a functional antibody portion. Therefore, all batches of monoclonal antibodies and derivatives must also be released by the PEI and the marketing authorization holder has to submit a batch release application. Under certain circumstances a waiver for certain products can be issued with regard to batch release. The conditions for such a waiver apply to the majority of monoclonal antibodies.

The network of official medicines control laboratories

Licensing, control and surveillance by competent authorities is the basis for ensuring efficacy, safety and quality of medicines in Europe. The control of the quality of medicines by national control laboratories, known as Official Medicines Control Laboratories (OMCLs) is an essential step in this process; it encompasses controls before and after granting a marketing authorisation. For certain groups of biomedical medicines (vaccines for human and veterinary use, medicines derived from human plasma) even each batch is controlled before it can be placed on the market. As single OMCLs would not be able to cope with their task, given the large number and diversity of medicines, in 1994 the OMCL network was founded upon initiative of the European Directorate for the Quality of Medicines & HealthCare, in close collaboration with the Commission of the European Union. Currently 68OMCLs from 39countries are part of the network. Prerequisite for the smooth operation of the OMCL network is the harmonisation of the quality management system of the individual OMCLs, based on the ISO17025 standard, internal guidelines and the European Pharmacopoeia. Compliance with these standards is checked through regular audits, thus creating the basis for mutual recognition of test results. The collaboration in the OMCL network for the surveillance of the medicines market, the official control authority batch release and the fight against counterfeiting and illegal medicines enables OMCLs to keep pace with the developments in the field of medicines and to control the broad spectrum of medicines. In the 20years since its start, the OMCL network has become a European success story.

Development and validation of a reversed-phase HPLC method for simultaneous analysis of butylhydroxyanisol, simvastatin and its impurities in tablet dosage forms

A simple, rapid, and sensitive RP-HPLC method using photodiode array detection was developed and validated for the simultaneous determination of butylhydroxyanisol and simvastatin with its impurities in tablet forms. Chromatographic separation was achieved on a Phenomenex Hypersil (250×4.6 mm, 5 μm) column using the mobile phase acetonitrile-sodium acetate (12 mM) buffered to 4.2 with glacial acetic acid. The flow rate was 1.7 mL/min, and the UV detection were made at 238 nm for simvastatin and its impurities and at 290 nm for butylhydroxyanisol. The system suitability solution used for peak impurity identification was generated in-situ without use of any impurity reference standard. The method was validated according to ICH Q2(R1) guidelines, and the acceptance criteria for accuracy, precision, linearity, specificity, robustness, LOD, and LOQ, were met in all cases. Moreover, the reproducibility results obtained by 22 Official Medicines Control Laboratories (OMCL) of European Directorate were satisfactory. The compounds selected for impurity validation were based on those found during long term and accelerate stability studies carried out on several formulation tablets from Moroccan and other markets. The described method was robust and successfully applied in quality control laboratories for routine analysis to determine the butylhydroxyanisol and simvastatin with its impurities content in tablet dosage forms.

Determination of ochratoxin A in Capsicum spp. (paprika and chili) by immunoaffinity column cleanup and liquid chromatography: collaborative study.

A method validation study for the determination of ochratoxin A in Capsicum spp. (paprika and chili) was conducted according to the International Union of Pure and Applied Chemistry harmonized protocol. The method is based on the extraction of samples with aqueous methanol, followed by an immunoaffinity column cleanup. The determination is carried out by RP-HPLC coupled with a fluorescence detector. The study involved 21 participants representing a cross-section of research, private, and official control laboratories from 14 European Union (EU) Member States and Singapore. Mean recoveries reported ranged from 83.7 to 87.5%. The RSD for repeatability (RSDr) ranged from 1.7 to 14.3%. The RSD for reproducibility (RSDR) ranged from 9.1 to 27.5%, reflecting HorRat values from 0.4 to 1.3 according to the Horwitz function modified by Thompson. The correction for recovery of results from naturally contaminated samples further improved the reproducibility of the method. The method showed acceptable within-laboratory and between-laboratory precision for each matrix, and it conforms to requirements set by current EU legislation.

Development and validation of an analytical method for the determination of arsenic, cadmium and lead content in powdered infant formula by means of quadrupole Inductively Coupled Plasma Mass Spectrometry

Cadmium (Cd), lead (Pb) and arsenic (As) can enter the food chain through the environment and/or as a consequence of the manufacturing process making foodstuffs the main human exposure route to these chemical elements. The risk associated with this exposure is of such a big concern for human health that the European Food Safety Agency recommends to reduce the exposure to Cd and Pb so as to protect especially vulnerable subgroups of population (e.g., infants). Therefore, the setting of new maximum levels (MLs) for chemical elements in infant formulae (e.g., for Cd) or the reconsideration of the existing ML for Pb is under discussion. On this basis, the availability of analytical methods, precise, accurate and sensitive enough to quantify low concentration values, is a key point especially for official control laboratories that have to state the sample compliance using a fully validated method with an associated uncertainty compliant with the requirements specified in the pertinent regulations. This work describes the development and validation of an analytical method to quantify As, Cd and Pb in powdered infant formulae based on animal protein at values of concentration close to the MLs that are likely to be set. The results obtained make the method suitable for a precise and accurate determination of these chemical elements at these low concentration values. In particular, the results for limit of quantification (LoQ) were respectively (μg kg−1): As 6.2, Cd 1.2 and Pb 4.5. While for the recovery rates the following percentages were obtained: As 105%, Cd 98% and Pb 108%. The expanded uncertainties were found extremely satisfactory (Cd 13% and Pb 19%). The LoQ and the uncertainty for Pb meet the requirements set in Commission Regulation (EC) No. 333/2007 and following amendments being lower than the maximum values allowed. Even for Cd the expanded uncertainty resulted adequate in relation with the low concentration considered.

Multi-analyte methods for the detection of photoinitiators and amine synergists in food contact materials and foodstuffs – Part II: UHPLC-MS/MS analysis of materials and dry foods

The aim of this investigation was to develop a multi-analyte method for the analysis of a total of 53 photoinitiators and amine synergists in food contact materials and foodstuffs. As for many of these compounds a maximum LOD of 10 µg kg−1 food applies, a sensitive and selective detection method is needed to control at these limits. Here an UHPLC-MS/MS was chosen to achieve this object. In the end 49 compounds could be integrated into one analytical method. This is nearly twice as many compared with other by now available methods. Only 11.5 min are needed for the analysis of one sample, allowing a high sample throughput. The LODs, which were determined in acetonitrile in the absence of matrix interferences, are sufficient to control at the legally acceptable limits, except for five photoinitiators. The developed method was tested for the analysis of food contact materials and foodstuffs. In the latter case a muesli matrix was spiked at four different concentration levels to determine the recovery rates. Extractions were performed in each case with acetonitrile. For 87% of the photoinitiators and amine synergists recoveries from the muesli were in the range between 70% and 120%. Thus, a comprehensive detection method for the analysis of food contact materials and foodstuffs for these potential migrating substances is now available, allowing the safe identification and control of migration levels in foodstuffs for the majority of the tested compounds. In particular, this multi-analyte method is worthwhile for official control laboratories where normally no information about the composition of applied inks on the food contact materials is available and thus target analyses are not feasible.

Multi-analyte methods for the detection of photoinitiators and amine synergists in food contact materials and foodstuffs – Part I: HPLC-DAD screening of materials

The objective of this work was to develop a HPLC-DAD method suitable for the screening of food contact materials for a total of 63 monomeric and polymeric photoinitiators and amine synergists. Such multi-analyte methods are worthwhile for official control laboratories, where normally no information about the composition of the applied inks or varnishes on the printed or lacquered materials is available and thus target analyses are not feasible. The polymeric analytes were each separated in a multitude of substance peaks, which largely overlaid those of the other compounds. Thus, for 13 polymeric photoinitiators and amine synergists a hydrolysis method was developed that reduced the number of ultraviolet (UV) detectable peaks to only one. This allowed easier identification and – preliminary – semi-quantification of these polymeric substances with adequate limits of detection. The remaining 50 photoinitiators and amine synergists were combined in one HPLC-DAD method. But since many of these substances are structurally related, partly retention times and spectra did not differ significantly. Thus selectivity was enhanced by preparing a database containing all spectra and retention times of the investigated compounds. Furthermore, the retention times of those 50 substances were calculated relative to two internal standards to overcome variances of retention from run to run or due to matrix effects. The developed method was tested for the analysis of food contact materials. Extractions of these were performed with acetonitrile and partially the extracts were subsequently concentrated in a steam of nitrogen. Limits of detection of photoinitiators and amine synergists in concentrated packaging extracts were in the range between 0.02 and 5.5 µg dm−2.

High-throughput histamine analysis approach in an official control laboratory: Analytical methods and four years fish products results

A highly practical two-tier approach involving a screening and a confirmatory method was set up to efficiently test histamine in fish products in the frame of official controls. After their validation, the routine management of the two procedures was simplified as far as possible ensuring a strict quality data control and maximizing the cost-effectiveness. Accordingly five hundred and ninety batches of fish products (3129 determinations) sampled from the Italian authorities were successfully analyzed over a four year period (2008–2012). Only a small percentage of analysed batches (4.9%) was judged non-compliant. The examination of irregular cases (fish species, processing technology and storage practices) suggests important considerations in order to minimise the histamine risk for consumers.

Exploiting interlaboratory comparisons

Many individuals and laboratory teams, respectively, experience some kind of surprise when they are starting to compare their own measurement results with the ones from other laboratories. It could be a positive astonishment, namely how well the results are matching for a given measurand and sample. More often the contrary is observed and the origin of the discrepancies has to be identified. However, the potential of an interlaboratory comparison (ILC) including its evaluation depends strongly on the ILC design and the amount of information provided by the participants. This is not different from any other scientific study. But there are still several myths about the ‘do and don’t’ for ILCs. For instance, opinions such as ‘never combine measurement results from an ILC to assign a property value to a reference material’ or ‘increase the number of ILC participants for better approaching the true value’ are voiced at conferences or in committee meetings. Nevertheless, recent years have seen significant progress in the common understanding of underlying scientific principles and concepts of ILCs as well as in their design and execution. This was and continues to be driven by the needs to demonstrate the analytical capabilities (proficiency) of a set of laboratories, to identify the performance (limits) of a particular measurement method (actually a ‘measurement procedure’) or to characterize a specific property of the material under investigation. In the past, such judgments were left to some individuals or institutions, often based on a non-transparent division into ‘experts’ and ‘non-experts.’ It is interesting to note that the enhanced globalization of science, industry, trade, people’s mobility, communication, etc., has also put the traditional way of defining experts and competences in question — at least partially. Nowadays, it is usually not sufficient anymore to be identified by a well-known scientific ‘heavy weight’ or to belong to a traditionally well-reputed institution. One has regularly to provide evidence for the claimed competence. ILCs can be a relatively independent route for demonstrating specific competencies in measurement tasks. This is increasingly recognized also by regulators. For instance, official control laboratories for food or environmental monitoring in the European Union are required by legislation to successfully participate in dedicated ILCs. A prerequisite for the wider acceptance of ILC as a quality assurance tool was the combination of metrological principles for ILC designs with dedicated elements of standardization and internationally harmonized surveillance approaches via accreditation. This ranges from demanding participation in proficiency testing of laboratories which wish to obtain and keep an accreditation according to ISO/IEC 17025, to ensuring quality criteria for proficiency testing via application of ISO/IEC 17043. The latter document also contains a list of different goals which may be targeted by ILCs. In this respect, it is important to consider the interrelation between the three main components of a measurement exercise: the material (sample under investigation), the method(s) (measurement procedures used including all sample preparation and manipulation steps), and the laboratories participating. One cannot separately assess more than one of these components in the same ILC. For instance, in the framework of the characterization study of a new candidate reference material, the applied measurement methods have to be validated before applying them by laboratories of known (proven) competence. Measurement results obtained in such designed ILCs can be used for assigning property H. Emons (&) Geel, Belgium e-mail: JRC-IRMM-ACQUAL@ec.europa.eu

Impedance spectroscopy for rapid determination of honey floral origin

In this work electrical impedance spectroscopy was applied as an alternative method for floral origin determination of unifloral honeys, which may supplement the labeling according to the European Legislation. Impedance measurements, in agreement with data from routine analyses, allowed to distinguish the unifloral honey samples and to acquire information on chemical and physical properties, such as conductivity, ash content and acidity. Equivalent electrical circuits have been extracted for each unifloral honey sample, which have been validated by means of electrical simulation, and every electrical component has been associated to a specific honey characteristic. It can be concluded that the method developed here permits rapid and easy determination of honey floral origin, no sample preparation procedure is required and it could be used in the official control laboratories.

Accreditation of a Screening Method for Non–Dioxin-like Polychlorinated Biphenyl Detection in Fishery Products according to European Legislation

European Commission Regulation 882/2004/EC requires that official control laboratories for foodstuffs in the member states are certified according to UNI EN ISO/IEC 17025:2005 (general requirement for the competence of calibration and testing laboratories). This mandatory requirement has resulted in a continuous adaptation and development of analytical procedures. The aim of this study was to develop a method for semiquantitative screening of polychlorinated biphenyls in fish for human consumption. According to the Commission Decision 657/2002/CE, the detection capability, the precision, the selectivity-specificity, and applicability-ruggedness-stability were determined to validate the method. Moreover, trueness was verified. This procedure resulted in rapid execution, which allowed immediate and effective intervention by the local health authorities to protect the health of consumers. Finally, the procedure has been recognized by the Italian accrediting body, ACCREDIA.