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1.
PLoS One ; 18(7): e0289120, 2023.
Article in English | MEDLINE | ID: mdl-37486909

ABSTRACT

The current food chain both contributes to, and is affected by, climate change. While GHG emissions and emissions to water and soil are a problem for the whole food chain, the majority of such emissions and the major solutions to them can be found in the farming and land use sector. The farming system needs to reduce its greenhouse-gas emissions and adapt its supply chain to cope with climate change. A broad variety of payment tools have been proposed to motivate farmers and landowners to take certain actions to reduce greenhouse gas emissions and encourage the protection or restoration of natural resources. The protocol described here (OSF preregistration https://doi.org/10.17605/OSF.IO/STGQ6) outlines the methodology for a systematic review to explore how financial mechanisms such as green bonds can provide incentives to agri-food sector to support environmental sustainability and ecosystem service delivery through land-use change. Our primary research question is: how do financial mechanisms incentivize land restoration? Studies will be categorized according to the types of financial mechanisms, their characteristics, methods of land restoration and their impact on mitigating agri-food footprint. The results are expected to increase our understanding about the design of financing tools currently used to accelerate nature restoration. Moreover, they will inform us about the effectiveness of deploying such tools on rural communities, food companies and landowners.


Subject(s)
Ecosystem , Greenhouse Gases , Greenhouse Effect , Conservation of Natural Resources/methods , Soil/chemistry , Agriculture/methods , Systematic Reviews as Topic
2.
Compr Rev Food Sci Food Saf ; 21(6): 4776-4811, 2022 11.
Article in English | MEDLINE | ID: mdl-36254736

ABSTRACT

Historically, food fraud was a major public health concern which helped drive the development of early food regulations in many markets including the US and EU market. In the past 10 years, the integrity of food chains with respect to food fraud has again been questioned due to high profile food fraud cases. We provide an overview of the resulting numerous authoritative activities underway within different regions to counter food fraud, and we describe the guidance available to the industry to understand how to assess the vulnerability of their businesses and implement appropriate mitigation. We describe how such controls should be an extension of those already in place to manage wider aspects of food authenticity, and we provide an overview of relevant analytical tools available to food operators and authorities to protect supply chains. Practical Application: Practical Application of the provided information by the food industry in selecting resources (guidance document, analytical methods etc.).


Subject(s)
Food , Fraud , Food-Processing Industry , Food Industry
3.
Food Chem ; 394: 133300, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-35777252

ABSTRACT

In this work a SPE/GC-FID method, incorporating the use of a 1-g silica cartridge, for the determination of FAEE in olive oils is presented. The procedure has been fully validated, initially 'in-house' and subsequently by an international validation study involving sixteen laboratories from Europe, the United States of America, and China. Key performance parameters of the method are: (1) Linearity in the 10-134 mg/kg range (R2 > 0.999), (2) LOD and LOQ < 0.5 mg/kg, (3) RSDr < 10%, (4) RSDR < 20% (for 4 out of 5 test materials). In addition, the method has been demonstrated to provide equivalent results to the Official Method (Commission Regulation 2568/91) while providing advantages in terms of reductions in time and solvents and ease of automation. In fact, the proposed protocol requires 30 mL solvents and takes 1.5 h per determination instead of the 350 mL and 6 h needed in the UE Official Method.


Subject(s)
Esters , Fatty Acids , China , Olive Oil , Solvents
4.
Food Res Int ; 123: 712-721, 2019 09.
Article in English | MEDLINE | ID: mdl-31285021

ABSTRACT

Food is traded across the global markets to satisfy consumer demands, mainly from developed countries, for year-round access to a wide range of foods. This has resulted in an increasingly complex network of food trade and has made importing countries vulnerable to the spread of foodborne disease outbreaks originating from "foreign" food networks. Analysis of these networks can provide information on potential food safety risks and also on the potential spread of these risks through the food network in question. In this study, network theory has been used to analyse global trade. A mathematical model was developed enabling a simulation of the distribution of food products based on the publicly available data on international imports, exports and production provided by the Food and Agriculture Organization of the United Nations. Through numerical simulations we demonstrate, for the first time, the impact that the network structure has on the distribution of food products in terms of food safety risks. As a case study, a recent trans-national food safety incident was analysed, illustrating the potential application of the model in a foodborne pathogen outbreak. Using only the type of contaminated food and the countries where the outbreak was reported, the model was used to identify the most likely origin of the contaminated eggs, narrowing down the options to three countries (including the actual origin). Furthermore, it is used to identify those countries with significant food safety risks, due to imports of food produced in these three countries. The approach can help regulatory agencies and the food industry to design improved surveillance and risk mitigation actions against transnational food safety risks.


Subject(s)
Disease Outbreaks , Food Safety , Foodborne Diseases/epidemiology , Models, Theoretical , Databases, Factual , Food Contamination , Food Microbiology , Food-Processing Industry , Risk Factors
5.
J Agric Food Chem ; 54(17): 6261-5, 2006 Aug 23.
Article in English | MEDLINE | ID: mdl-16910717

ABSTRACT

This paper describes the composition of 30 grape-seed oils obtained from France, Italy, and Spain during 2002-2003. Oils were extracted from the seeds using small-scale industrial solvent extraction equipment and analyzed in their unrefined state using standard methods for fatty acids, fatty acids in the triacylglycerol 2-position, tocopherols and tocotrienols, triglycerides, sterols, steradienes, and iodine value. Values for the composition of the sterols, triglycerides, fatty acids, iodine value, and tocopherol composition were generally in good agreement with the results of previous similar surveys. Steradienes (stigmastadiene, campestadiene, stigmastatriene, and campestatriene) were detected in the oil and were probably formed from sterols during the extraction process.


Subject(s)
Plant Oils/chemistry , Seeds/chemistry , Vitis/chemistry , Fatty Acids/analysis , France , Iodine/analysis , Italy , Phytosterols/analysis , Soil/analysis , Spain , Tocopherols/analysis , Triglycerides/analysis , Vitis/growth & development
6.
J Agric Food Chem ; 54(17): 6266-70, 2006 Aug 23.
Article in English | MEDLINE | ID: mdl-16910718

ABSTRACT

This paper describes the composition of sesame seed oils obtained from seeds collected from five countries that are major suppliers of traded sesame seed oil. Oils were extracted from the seeds using small-scale industry pressing equipment and analyzed using standard methods for fatty acids, fatty acids in the triglyceride 2-position, tocopherols and tocotrienols, triglycerides, sterols, steradienes, and iodine value. Values for the composition of the sterols, triglycerides, fatty acids, iodine value, and tocopherol composition were generally in good agreement with the results published elsewhere. All of the oils from roasted seeds contained low levels of the sterol degradation products stigmasta-3,5-diene and campesta-3,5-diene, which were probably formed by dehydration of the parent sterols during roasting.


Subject(s)
Sesame Oil/chemistry , Environment , Fatty Acids/analysis , Food Handling/methods , Hot Temperature , Iodine/analysis , Phytosterols/analysis , Sesamum/growth & development , Tocopherols/analysis , Tocotrienols/analysis , Triglycerides/analysis
7.
Food Addit Contam ; 23(1): 84-92, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16393818

ABSTRACT

A study has been carried out to assess appropriate statistical models for use in evaluating retail sampling plans for the determination of mycotoxins in food. A compound gamma model was found to be a suitable fit. A simulation model based on the compound gamma model was used to produce operating characteristic curves for a range of parameters relevant to retail sampling. The model was also used to estimate the minimum number of increments necessary to minimize the overall measurement uncertainty. Simulation results showed that measurements based on retail samples (for which the maximum number of increments is constrained by cost) may produce fit-for-purpose results for the measurement of ochratoxin A in dried fruit, but are unlikely to do so for the measurement of aflatoxin B1 in pistachio nuts. In order to produce a more accurate simulation, further work is required to determine the degree of heterogeneity associated with batches of food products. With appropriate parameterization in terms of physical and biological characteristics, the systems developed in this study could be applied to other analyte/matrix combinations.


Subject(s)
Food Analysis/methods , Food Contamination/analysis , Models, Statistical , Mycotoxins/analysis , Aflatoxin B1/analysis , Fruit/chemistry , Humans , Ochratoxins/analysis , Pistacia/chemistry
8.
J AOAC Int ; 88(4): 1197-204, 2005.
Article in English | MEDLINE | ID: mdl-16152940

ABSTRACT

An interlaboratory study was performed on behalf of the UK Food Standards Agency to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatographic (LC) method for the determination of deoxynivalenol in a variety of cereals and cereal products at proposed European regulatory limits. The test portion was extracted with water. The sample extract was filtered a applied to an immunoaffinity column. After being washed with water, the deoxynivalenol was eluted with acetonitrile or methanol. Deoxynivalenol was quantitated by reversed-phase LC with UV determination. Samples of artificially contaminated wheat-flour, rice flour, oat flour, polenta, and wheat based breakfast cereal, naturally contaminated wheat flour, and blank (very low level) samples of each matrix were sent to 13 collaborators in 7 European countries. Participants were asked to spike test portions of all samples at a range of deoxynivalenol concentrations equivalent to 200-2000 ng/g deoxynivalenol. Average recoveries ranged from 78 to 87%. Based on results for 6 artificially contaminated samples (blind duplicates), the relative standard deviation for repeatability (RSDr) ranged from 3.1 to 14.1%, and the relative standard deviation for reproducibility (RSDR) ranged from 11.5 to 26.3%. The method showed acceptable within-laboratory and between-laboratory precision for all 5 matrixes, as evidenced by HorRat values < 1.3.


Subject(s)
Chemistry Techniques, Analytical/methods , Chromatography, Liquid/methods , Edible Grain/metabolism , Food Contamination , Immunochemistry/methods , Trichothecenes/analysis , Acetonitriles/analysis , Analysis of Variance , Calibration , Chromatography, Affinity , Chromatography, Liquid/instrumentation , Food Analysis/methods , Methanol/analysis , Reproducibility of Results , Ultraviolet Rays
9.
Ind Health ; 43(3): 472-9, 2005 Jul.
Article in English | MEDLINE | ID: mdl-16100923

ABSTRACT

The European Union adopted a Directive in 2002 on minimum requirements for the health and safety of workers exposed to vibration. This is known as the Physical Agents (Vibration) Directive. It builds on existing general employers' duties to manage risks to health and safety, and introduces exposure action and limit values for both hand-arm vibration and whole-body vibration, setting minimum standards for the control of vibration risks across Europe. New Regulations on Vibration at Work will be introduced in Great Britain on 6 July 2005 to implement the Directive. These Regulations should serve to strengthen the continuing work of the Health and Safety Executive (HSE) to reduce exposures to hand-arm vibration in British industry. Implementation of the Directive for whole-body vibration presents a different challenge and the HSE is currently preparing appropriate guidance to accompany the Regulations. This will form part of an holistic approach to back pain in professional drivers, setting vibration in context with other risk factors, particularly postural concerns and manual handling operations.


Subject(s)
Occupational Exposure/legislation & jurisprudence , Vibration , European Union , Humans
10.
J Agric Food Chem ; 53(12): 4843-52, 2005 Jun 15.
Article in English | MEDLINE | ID: mdl-15941325

ABSTRACT

This paper describes the composition of authentic hazelnut oils obtained from nuts collected from five countries that are major suppliers of hazelnut oil. Oils were analyzed using standard methods for fatty acids, fatty acids in the triacylglycerol 2-position, tocopherols and tocotrienols, triacylglycerols, sterols, steradienes, and iodine value. The results were generally in good agreement with those of other publications. Tocotrienols, previously unreported in hazelnut oil, were detected in one sample. There were no major differences in the composition of oils from different countries. Roasting the nuts prior to pressing had little effect on oil composition.


Subject(s)
Corylus/chemistry , Plant Oils/chemistry , Seeds/chemistry , Fatty Acids/analysis , Iodine/analysis , Sterols/analysis , Tocopherols/analysis , Tocotrienols/analysis , Triglycerides/analysis
11.
J Agric Food Chem ; 53(12): 4853-60, 2005 Jun 15.
Article in English | MEDLINE | ID: mdl-15941326

ABSTRACT

This paper describes the composition of walnut oils obtained from nuts collected from seven countries that are major suppliers of walnut oil. Oils were extracted from the nuts using small-scale industry pressing equipment and analyzed using standard methods for fatty acids, fatty acids in the triacylglycerol 2-position, tocopherols and tocotrienols, triacylglycerols, sterols, steradienes, and iodine value. Values for the composition of the sterols, triacylglycerols, fatty acids, iodine value, and tocopherol composition were generally in good agreement with the results of previous similar surveys. Tocotrienols were not detected in any sample. Steradienes (stigmastadiene, campestadiene, stigmastatriene, and campestatriene) were not detected in any oil.


Subject(s)
Juglans/chemistry , Plant Oils/chemistry , Fatty Acids/analysis , Iodine/analysis , Quality Control , Sterols/analysis , Tocopherols/analysis , Triglycerides/analysis
12.
J AOAC Int ; 88(1): 121-7, 2005.
Article in English | MEDLINE | ID: mdl-15759734

ABSTRACT

A method is described for the determination of hydroxymethylfurfural (HMF) in honey. The method, which is based on solid-phase extraction cleanup followed by liquid chromatography (LC) with UV absorbance detection, was tested on a variety of different honey types: liquid, set, blended, filtered, crystalline, and comb honey. A sample of honey fortified with a known amount of HMF acted as an in-house reference material. LC with diode-array detection showed that the HMF peak did not contain any peaks of coeluting interfering species. Stability studies showed that honey samples should not be repeatedly frozen and thawed because the temperature changes caused a gradual increase in the HMF concentration. It was also shown that aqueous HMF standard solutions should be kept in the dark at 4 degrees C to avoid degradation of the HMF. The method was internally validated, and the measurement uncertainty was estimated to be +/-9.0 at 40 mg/kg, the legal limit. A comparison of the relative standard uncertainty with the Horwitz relative standard deviation showed that the method was suitable for its purpose and should be validated by a collaborative trial.


Subject(s)
Chemistry Techniques, Analytical/methods , Chromatography, Liquid/methods , Food Analysis/methods , Furaldehyde/analogs & derivatives , Furaldehyde/analysis , Chromatography , Honey , Models, Statistical , Spectrophotometry , Temperature , Ultraviolet Rays
13.
J AOAC Int ; 88(6): 1733-40, 2005.
Article in English | MEDLINE | ID: mdl-16526456

ABSTRACT

An interlaboratory study was performed on behalf of the UK Food Standards Agency to evaluate the effectiveness of an affinity column cleanup liquid chromatography (LC) method for the determination of zearalenone (ZON) in a variety of cereals and cereal products at proposed European regulatory limits. The test portion is extracted with acetonitrile:water. The sample extract is filtered, diluted, and applied to an affinity column. The column is washed, and ZON is eluted with acetonitrile. ZON is quantified by reversed-phase LC with fluorescence detection. Barley, wheat and maize flours, polenta, and a maize-based baby food naturally contaminated, spiked, and blank (very low level) were sent to 28 collaborators in 9 European countries and 1 collaborator in New Zealand. Participants were asked to spike test portions of all samples at a ZON concentration equivalent to 100 microg/kg. Average recoveries ranged from 91-111%. Based on results for 4 artificially contaminated samples (blind duplicates) and 1 naturally contaminated sample (blind duplicate), the relative standard deviation for repeatability (RSDr) ranged from 6.9-35.8%, and the relative standard deviation for reproducibility (RSDR) ranged from 16.4-38.2%. The method showed acceptable within- and between-laboratory precision for all 5 matrixes, as evidenced by HorRat values <1.7.


Subject(s)
Flour/analysis , Food Analysis/methods , Hordeum/metabolism , Infant Food/analysis , Triticum/metabolism , Zea mays/metabolism , Zearalenone/analysis , Calibration , Chemistry Techniques, Analytical/methods , Chromatography, Affinity/methods , Chromatography, Liquid , Food Contamination , Humans , Indicators and Reagents , Infant, Newborn , Microscopy, Fluorescence , Models, Statistical , Molecular Weight , Reproducibility of Results , Sensitivity and Specificity
14.
J AOAC Int ; 88(5): 1404-12, 2005.
Article in English | MEDLINE | ID: mdl-16385990

ABSTRACT

An interlaboratory study was performed to evaluate the effectiveness of a headspace gas chromatography (GC) method for the determination of 1,3-dichloro-propan-2-ol (1,3-DCP) in soy sauce and related products at levels above 5 ng/g. The test portion is mixed with an internal standard (d5-1,3-DCP) and ammonium sulfate in a sealed headspace vial. After achieving equilibrium, the headspace is sampled either by gas-tight syringe or solid-phase microextraction (SPME) and analyzed by GC with mass spectrometric detection. 1,3-DCP is detected in the selected-ion mode (monitoring m/z 79 and 81 for 1,3-DCP and m/z 82 for the deuterated internal standard) and quantified by measurement against standards. Test materials comprising soy, dark soy, mushroom soy, and teriyaki sauces, both spiked and naturally contaminated, were sent to 9 laboratories in Europe, Japan, and the United States; of these, 5 used SPME and 4 used syringe headspace analysis. Test portions were spiked at 5.0, 10.0, 20.0, 100.0, and 500.0 ng/g. The average recovery for spiked blank samples was 108% (ranging from 96-130%). Based on results for spiked samples (blind pairs at 5, 10, 20, 100, and 500 ng/g) as well as a naturally contaminated sample (split-level pair at 27 and 29 ng/g), the relative standard deviation for repeatability (RSDr) ranged from 2.9-23.2%. The relative standard deviation for reproducibility (RSDR) ranged from 20.9-35.3%, and HorRat values of between 1.0 and 1.6 were obtained.


Subject(s)
Food Analysis/methods , Gas Chromatography-Mass Spectrometry/methods , Soy Foods/analysis , alpha-Chlorohydrin/analogs & derivatives , Calibration/standards , Reproducibility of Results , alpha-Chlorohydrin/analysis
15.
J AOAC Int ; 87(5): 1179-88, 2004.
Article in English | MEDLINE | ID: mdl-15493676

ABSTRACT

The aim of the present study was to provide the official wine control authorities with an internationally validated method for the determination of 3-methoxy-1,2-propanediol (3-MPD) and cyclic diglycerols (CycDs)-both of which are recognized as impurities of technical glycerol-in different types of wine. Because glycerol gives a sweet flavor to wine and contributes to its full-body taste, an economic incentive is to add glycerol to a wine to mask its poor quality. Furthermore, it is known that glycerol, depending on whether it is produced from triglycerides or petrochemicals, may contain considerable amounts of 3-MPD in the first case or CycDs in the second. However, because these compounds are not natural wine components, it is possible to detect glycerol added to wine illegally by determining the above-mentioned by-products. To this end, one of the published methods was adopted, modified, and tested in a collaborative study. The method is based on gas chromatographic/mass spectrometric analysis of diethyl ether extracts after salting out with potassium carbonate. The interlaboratory study for the determination of 3-MPD and CycDs in wine was performed in 11 laboratories in 4 countries. Wine samples were prepared and sent to participants as 5 blind duplicate test materials and 1 single test material. The concentrations covered ranges of 0.1-0.8 mg/L for 3-MPD and 0.5-1.5 mg/L for CycDs. The precision of the method was within the range predicted by the Horwitz equation. HORRAT values obtained for 3-MPD ranged from 0.8 to 1.7, and those obtained for CycDs ranged from 0.9 to 1.3. Average recoveries were 104 and 109%, respectively.


Subject(s)
Diglycerides/analysis , Glyceryl Ethers/analysis , Wine/analysis , Gas Chromatography-Mass Spectrometry
16.
J Agric Food Chem ; 52(17): 5463-71, 2004 Aug 25.
Article in English | MEDLINE | ID: mdl-15315386

ABSTRACT

The potential for the Fusarium mycotoxins 4-deoxynivalenol (DON) and zearalenone (ZON) to enter the human food chain through contaminated eggs was assessed using a controlled feed study. Four groups of laying hens (eight in each group) were fed a diet that included differing amounts of naturally contaminated wheat containing DON ( approximately 20 mg kg(-1)) and ZON (0.5 mg kg(-1)). Eggs were collected and pooled from each group on a daily basis. Pooled samples were analyzed by liquid chromatography with mass spectrometry detection (LC-MS/MS). The method allowed DON, other type B trichothecenes, ZON, and its metabolites to be determined in a single multi-residue analysis. The selectivity of the MS/MS procedure allowed cleanup to be minimized (for DON, cleanup by immunoaffinity column was used) or eliminated (for ZON). The limits of detection of 0.01 microg kg(-1) for DON and 0.1 microg kg(-1) for ZON in eggs were lower than previously published methods. None of the samples analyzed had detectable levels of ZON or its metabolites. Although maximum levels of DON contamination (10 mg kg(-1) feed) were relatively high, no adverse effects were observed on egg production. On the basis of the determined DON levels in the hen's diet and the determined levels of DON in the corresponding eggs, transmission rates of 15 000:1, 18 000:1, and 29 000:1 for treatment levels 5, 7.5, and 10 mg DON kg(-1) feed, respectively, were found. These results show that, although eggs could be a human exposure route for DON, the levels are insignificant compared to the other sources, although the presence of metabolites of DON was not studied.


Subject(s)
Animal Feed/analysis , Eggs/analysis , Food Contamination/analysis , Oviposition/drug effects , Trichothecenes/analysis , Zearalenone/analysis , Animals , Chickens , Female , Mycotoxins/analysis , Trichothecenes/adverse effects , Triticum/chemistry , Zearalenone/adverse effects
17.
J AOAC Int ; 86(4): 722-8, 2003.
Article in English | MEDLINE | ID: mdl-14509431

ABSTRACT

Commercially available solid zearalenone (ZON) to be used as a certified liquid calibrant (BCR-699) in a project funded by the European Commission within the Standard Measurement and Testing program was characterized and its purity determined. The degree of purity of the ZON was examined by UV spectrophotometer, liquid chromatography (LC) with diode array and fluorescence detection, 1H and 13C-NMR spectrometry, LC-mass spectrometry (LC/MS/MS), ion chromatography (IC), and differential scanning calorimetry (DSC). The diagrams obtained from DSC analysis and the UV spectrum showed no detectable impurities. Likewise, no impurities were observed by LC analysis with both diode array and fluorescence detection. IC determination revealed negligible contamination of ZON with chloride of 0.020 +/- 0.005% and nitrate of 0.016 +/- 0.006%. Zearalanone (ZAN) was identified as one of 2 minor (0.2%) impurities by LC/MS/MS. The 1H-NMR measurements revealed an additional peak, which has not been previously reported in the literature. It could be identified as part of the ZON spectrum as the signal arising from the phenolic proton attached to C4'. The manufacturer states an additional contamination with 0.2% methylene chloride, which could be confirmed to an extent of 0.1% by 1H-NMR. Minor impurities, whose structures remain unknown, were discovered at 3.5 and < 1 ppm. Total percentage of impurities based on NMR measurement was estimated not to exceed 1%. A purity of 99.5% with a tolerance of +/- 0.5% was finally attributed to the ZON studied in this project.


Subject(s)
Zearalenone/chemistry , Zearalenone/standards , Calorimetry, Differential Scanning , Chromatography, Liquid/methods , Crystallization , Drug Contamination , Magnetic Resonance Spectroscopy , Mass Spectrometry , Reference Standards , Spectrophotometry, Ultraviolet
18.
J Agric Food Chem ; 51(7): 1801-6, 2003 Mar 26.
Article in English | MEDLINE | ID: mdl-12643633

ABSTRACT

An improved procedure for determining (13)C and (2)H isotope ratios, using gas chromatography-isotope ratio mass spectrometry (GC-IRMS), has been developed for identifying the addition of low cost commercial sugar syrups to apple juices and related products. Isotopic techniques are commonly used to identify the addition of low cost sugars to fruit juices and are difficult to circumvent as it is not economically viable to change the isotopic ratios of the sugars. The procedure utilizes the derivative hexamethylenetetramine, which is produced through chemical transformation of a sugar degradation product and provides position-specific (13)C and (2)H ratios that relate to the parent sugar molecule. The new procedure has advantages over methods using nitro-sugar derivatives in terms of analysis time and sensitivity. The differences between the delta(2)H per thousand and delta(13)C per thousand values of the 100 authentic apple juices and beet and cane commercial sugar syrups permit their addition to be reliably detected.


Subject(s)
Beverages/analysis , Carbohydrates/analysis , Fructose/chemistry , Fruit/chemistry , Malus/chemistry , Methenamine/analysis , Carbon Isotopes/analysis , Deuterium/analysis , Gas Chromatography-Mass Spectrometry/methods , Sensitivity and Specificity
19.
J AOAC Int ; 86(6): 1164-71, 2003.
Article in English | MEDLINE | ID: mdl-14979698

ABSTRACT

An interlaboratory study was performed on behalf of the Food Standards Agency to evaluate the effectiveness of an affinity column cleanup liquid chromatographic (LC) method for the determination of ochratoxin A in a variety of dried fruit at European regulatory limits. To ensure homogeneity before analysis, laboratory samples are normally slurried with water in the ratio of 5 parts fruit to 4 parts water, and test materials in this form were used in the study. The test portion was extracted with acidified methanol. The extract was filtered, diluted with phosphate-buffered saline, and applied to an affinity column. The column was washed and ochratoxin A was eluted with methanol. Ochratoxin A was quantified by reversed-phase LC. The use of post-column pH shift to enhance the fluorescence of ochratoxin A by the addition of 1.1 M ammonia solution to the column eluant is optional. Determination was by fluorescence. Currants, sultanas, raisins, figs, and mixed fruit (comprising dried pineapple, papaya, sultanas, prunes, dates, and banana chips), both naturally contaminated and blank (very low level), were sent to 24 collaborators in 7 European countries. Participants were asked to spike test portions of all test samples at a level equivalent to 5 ng/g ochratoxin A. Average recoveries ranged from 69 to 74%. Based on results for 5 naturally contaminated test samples (blind duplicates) the relative standard deviation for repeatability (RSDr) ranged from 4.9 to 8.7%, and the relative standard deviation for reproducibility (RSDR) ranged from 14 to 28%. The method showed acceptable within- and between-laboratory precision for all 5 matrixes, as evidenced by HORRAT values <1.3.


Subject(s)
Fruit/chemistry , Ochratoxins/analysis , Calibration , Chromatography, Affinity , Chromatography, Liquid , Immunochemistry , Indicators and Reagents , Solutions , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet
20.
Analyst ; 127(5): 689-91, 2002 May.
Article in English | MEDLINE | ID: mdl-12081049

ABSTRACT

Two foodstuffs, wheat and green coffee, have been sampled from bulk lots by multiple samplers in the sampling analogue of a collaborative trial. For wheat the variation between samplers, contributing to the standard deviation of sampling reproducibility, was significant for two analytes. No significant sampling reproducibility variation was found in the coffee results, although significant sampling repeatability variation was detected.


Subject(s)
Coffee/chemistry , Food Contamination/analysis , Specimen Handling/methods , Triticum/chemistry , Lead/analysis , Mass Spectrometry , Molybdenum/analysis , Nitrogen/analysis , Sensitivity and Specificity
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