References

Stajnbaher and F.J. Schenck, J AOAC Int., 86 (2003) 412. 3 J. Pawliszyn (Ed.), Applications of Solid Phase Microextraction, RSC Chromatography Monographs, Hertfordshire, 1999. 4 P. Sandra, B. Tienpont and F. David, J. Chromatogr. A, 1000 (2003) 299. 5 A. Handley (Ed.), Extraction Methods in Organic Analysis, Scheffield Academic Press, Scheffield, 1999. 6 S. Mitra (Ed.), Sample Preparation Techniques in Analytical Chemistry, Wiley, New Jersey, 2003. 7 L....

Ochratoxin A

As for OTA, the most recent European database is provided by the report of the SCOOP Task 3.2.7 232 . Basically, participants were asked to provide information on the exposure of the population to OTA in their country through the elaboration of the following categories of data 1 Occurrence data in food and beverages, including those from different methodological approaches (i.e., total diet, duplicate test portion) 3 Best estimate of dietary intake 4 Occurrence data in biological fluids and...

Anthelmintics and antifungals

Anthelmintic (deworming) compounds control parasitic infections. Benzimida-zoles are anthelmintics that contain a common 1,2-diaminobenzene nucleus most of them also have a carbamate functional group. Albendazole and fenbendazole are common drugs in this class. These drugs protect against roundworms and flukes by inhibiting the processes necessary for parasitic mitochondrial production of ATP 11 . The use of fenbendazole (Figure 2) can also increase the rate of weight gain in growing and...

Separation and concentration methods

Certainly, an optimum starting-point for the discussion about the separation and concentration methods in trace element analysis is the review published by Bachmann 55 , who suggests solvent extraction and ion-exchange chromatography 56-59 as the most suitable approaches to trace element analysis. Separation and concentration methods are extra-steps in an analysis they must be avoided if non-essential, since they are a possible cause of sample contamination. However, sometimes, separation is...

Occurrence In Food

It is not possible to obtain an absolute accounting of the rate of occurrence of violative veterinary drug residues in human food. The violation rate can depend greatly on not only the specific residue and matrix, but also on the number of samples analysed and the type of methodology utilized. Nevertheless, the results from several monitoring programs can be informative in evaluating the overall scope of the issue. In the U.S., one monitoring program for veterinary drug residues in meat...

Fourier transform ion cyclotron resonance and orbitrap mass analysers

An orbitrap mass analyser is the most recent addition to the set of tools that can be applied to identification, characterization and quantitation of compounds in complex systems. With its ability to deliver low-ppm mass accuracy and extremely high resolution, all within a time scale compatible with nano-LC separations, the orbitrap has become an instrument of choice for many proteomic applications since its commercial introduction in 2005 85,86 . However, its application to determine food...

Tranquilizers and antiinflammatory drugs

Drugs administered to food animals to treat acute conditions include tranquilizers and anti-inflammatory drugs (Figure 3). These medicines might be given to animals shortly before they are sent to slaughter, resulting in potentially high levels of residues that may persist in edible tissue. For example, tranquilizers, such as acepromazine, azaperone, chlorpromazine, propionlypromazine and xylazine, have been shown to reduce stress or aggressiveness during transport for certain species of pigs...

Future Trends

Currently, a strong trend is the screening of non-target migrants. The occurrence of migrants in food that are unforeseen or unexpected, such as degradation products, reaction products or non-intentionally added substances, as for example inks, highlights the necessity to develop techniques adapted to more effective screening. maximum permitted levels (usually respected) The validation of methods that cover a range of target migrants is also an important issue. The hurdle in this case when...

Minor mycotoxins 221 Ergot alkaloids

The first documented epidemic of ergotism likely occurred in 944-945 AD, when some 20,000 people of the Aquitane region of France (about half of the population) died of the effects of ergot poisoning. Ergoline or ergot alkaloids were first isolated from ergot, a black tuber-like non-endophytic fungus that infects grains and causes the disease known as ergotism. More specifically, the ergot alkaloids are produced by several species of Claviceps, a genus of fungi that invades the female portion...

Wet ashing

Wet ashing involves sample treatments with a mixture of acids. In literature, numerous compositions have been proposed for such mixtures, depending, in several cases, on the preference of the Analyst 24,38-43 . However, all have particular characteristics, strictly linked to the individual properties of the acids employed. Nitric and perchloric acids are very strong oxidizing agents. Generally, sulfuric acid is used with an additional substance such as hydrogen peroxide to yield a cleaner...

Approaches to overcome matrix effects in gas chromatography

Matrix-induced response enhancement, first described by Erney et al. 99 , is a matrix effect well-known mainly in the GC analysis of pesticide residues in food, negatively impacting quantitation accuracy of certain susceptible analytes 98 . When a real sample is injected, the matrix components tend to block active sites (mainly free silanol groups) in the GC inlet and column, thus reducing losses of susceptible analytes caused by adsorption or degradation on these active sites. This phenomenon...

PBDE levels in food and dietary intake in Europe and Asia

Table 4 provides a summary of the levels of PBDEs that have been measured in foodstuffs and fish oil dietary supplements in locations outside of the Americas. The table also summarizes the various estimates of dietary exposure derived from such studies. A recurrent message from both Europe and Asia is the important role played by the consumption of fish and seafood, with its ingestion typically comprising around 50 of overall dietary exposure. Related to this, there have been several studies...

Optical transduction

Many optical devices have been developed. On the basis of solid-phase fluoroimmunoassays combined with an optical transducer chip chemically modified with an analyte derivative for the measurement of different pesticides in water control analysis 101,102 , even for multidetection measuring pollutants at low nanogram per litre levels in single few-minutes analysis 103 . Different optical immunosensors have been constructed for the control of bacterial growth 104 . A variety of devices have been...

Chromatography and detection

Baseline separation of all HAs is a prerequisite for the multi-compound analysis method. Chromatographic conditions were optimized by Gross and Gruter 54 for the separation of 12 HAs in 1992. A more recent study evaluated HPLC columns for the separation of HAs for LC MS, and the same column material favored by Gross, containing ODS-80, was found to be optimal for HAs in the newer study 55 . Peak confirmation is a crucial problem when working with such low levels of HAs, since co-elution with...

Ambient mass spectrometry

In 2004 a novel ambient ionization technology, called Desorption ElectroSpray Ionization (DESI), was proposed by the Cooks group at Purdue University 63,64 . For the first time, surfaces can be probed and analysed by MS under real native ambient conditions, without any sample preparation or matrix addition. The typical lay-out of a DESI source is shown in Figure 6. In short, a pneumatically assisted electrospray is used to produce charged microdroplets Figure 6 Schematic view of a DESI source....

The food chain A global issue

The food chain as schematically represented by Figure 1 is rather complex and many factors worldwide play a role in the final issue of food quality and safety. Raw materials for feed and food production come from all over the world with very different local climate, harvesting and storage conditions, all having an impact on the occurrence of microbiological and chemical contaminants such as mycotoxins, pesticide residues, environmental pollution and packaging migrants. The feed producer will...

Wilson Wilsons Comprehensive Analytical Chemistry

FOOD CONTAMINANTS AND RESIDUE ANALYSIS Laboratori de Bromatologia i Toxicologia Facultat de Farmacia Universitat de Valencia Av. Vicent Andres Estelles s n. 461QQ Burjassot Valencia, Spain Amsterdam Boston Heidelberg London New York Oxford Paris San Diego San Francisco Singapore Sydney Tokyo US FDA, Animal Drugs Research Center, Denver Fed Ctr, Lakewood, CO 80225, USA Jean-Philippe Antignac LABERCA-Ecole Nationale V t rinaire de Nantes, Route de Gachet, BP 50707, F-44307 Nantes Cedex 3, France...

Antibiotics

Antibiotics are commonly administered to food animals both therapeutically and subtherapeutically. Several classes of antibiotics are used in livestock veterinary medicine. Sulfonamides are derivatives of sulfanilamide, one of the first drugs discovered to treat Streptococcal infections. Sulfamethazine and sulfadimethoxide are shown as examples of this class of drugs in Figure 1. Although not technically classified as antibiotics, these drugs are bacteriostatic agents that effectively interfere...

Solid phase extraction

This extraction procedure is more and more applied, being much faster, cheaper, and more versatile than most classical techniques. Moreover, SPE procedures are easily automated using robotics, or can be coupled on-line with chromatographic techniques. The principle of retention (enrichment) is analogous to LC and is suitable for low, intermediate and high polarity solutes. Commonly, SPE media are based on normal phase, reversed phase or ion exchange chromatography. Giving an overview of the...

Yessotoxins Ytxs

YTXs originally were isolated from the digestive glands of scallops (Patinopecten yessoensis) 106 . Originally classified as DSP toxins as they do not induce diarrhoea YTXs have now been removed from this category 33,34 . The YTXs are sulphonated polyether toxins (Figure 11) and have been reported in shellfish in several countries including, Japan 106 , Norway 107 , New Zealand 108 and Italy 109 . Structurally, YTX is unusual as it is a sulphonated polyether with eleven fused rings 106,110 ....

Sample Preparation Methods For Svocs And Nvocs

Food matrixes encompass a broad range of physical types and the selection of a sample preparation method is, in first instance, dictated by the sample structure, e.g., powders, vegetables, fruits, meat and fatty or non-fatty beverages (e.g., milk and yoghurt versus soft drinks and wines). With the exception of food samples directly soluble in an organic solvent, e.g., vegetable oils, all samples analysed for Figure 4 Headspace sampling of fragrances by SHS (A) and HSSE (B). A sample of 100 mg...

Physical and chemical properties

PBDEs The commercial products are waxy solids, have boiling points between 310 C and 425 C 8 and have low vapour pressures ranging from 3.9 to 13.3 Pa at 20-25 C 9 . Their solubility in water is very poor, especially that of the higher BDEs. The n-octanol water partition coefficient (log Kow) ranges between 4.3 and 9.9 9 . PBDEs are thermally labile and break down readily with heat, which enables them to act as effective FRs. Both aliphatic and aromatic carbon-bromine covalent bonds are...

Biomimics Molecularly Imprinted Polymers Mips

Due to the frequently poor stability (thermal, pH) and short life times of biological components, synthetic molecules with high affinity properties, similar Table 3 Examples of immunosensors for food contaminants analysis Pesticides and herbicides Atrazine Atrazine Atrazine Atrazine Carbaril Chlorsulfuron Inhibition assay and electrochemical detection Inhibition assay and optical detection Indirect assay and TIR-fluorescence detection Indirect assay and SPR Indirect assay and SPR Competitive...

Supported liquidliquid extraction

SLLE uses a diatomaceous earth material placed in a cartridge to adsorb the aqueous phase by hydrophilic interactions. An efficient LLE occurs when a water immiscible solvent is applied. The high surface area at the interface between the organic and aqueous phase increases efficiency while eliminating the possibility of emulsion formation (e.g., in extracting milk). The analytes are then eluted as the solvent passes through the adsorbent. Selective extraction for acids and bases can be obtained...

Conclusions And Future Trends

MS, combined with chromatography or not, is really needed in a routine food laboratory carrying out monitoring of contaminants and residues. Both GC-MS and LC-MS are indispensable tools to determine food contaminants and residues. Nowadays, LC-MS has become a priority without substituting GC-MS. They are not competitive but complementary techniques. A laboratory for food contaminants and residue analysis requires, at least, both types of instruments because each one has its own field of work....

BAgonists

The control of b-agonists misuse received extra attention after outbreaks of food poisoning in 1990 in Spain caused by consumption of bovine liver. This was the first time that pharmacological residues found in slaughtered cattle were found to have caused acute intoxication in consumers. As therapeutic drugs, they have been first used as a bronchodilator for the treatment of pulmonary diseases in humans and animals. b-Agonists act specifically by binding to cell membrane b-receptors, and...

Determination of total ANC

The method generally used for total ANC depends on the finding that HBr, but not HCl, reacts with NOC to produce NO (Equations (11) and (12)) 68 . The ANC method was introduced in 1976-1978 by the Walters group 111,112 . Solutions of ANC, generally but not necessarily in water, are treated with SA under acidic conditions to destroy any nitrite present. SA also eliminates a slight response due to nitrate 13 . The resulting solution is injected into a mixture containing HBr, which reacts with NOC...

Levels of HBCDs and TBBPA in food and dietary intake

Table 5 provides a summary of the levels of total HBCDs that have been measured in foodstuffs. Similar to PBDEs, the consumption of fish and seafood plays an important role in the dietary exposure to HBCDs. This is particularly true for fish caught in locations contaminated with HBCDs, such as the Western Scheldt estuary (The Netherlands), or point sources located along rivers Cinca (Spain), Viskan (Sweden) and Tees (UK) 142 . Concentrations of HBCDs in fish were mostly between 10 and 1 000 ng...

Growth hormone

Growth hormone (GH), also known as somatotropin (ST), is a 22-kDa protein naturally produced by the anterior pituitary gland. STs are important factors influencing metabolic and somatogenic processes including growth, immune function, reproduction and lactation in mammals 92-95 . It was known as early as the 1930s that the injection of dairy cows with pituitary extracts increased milk yield 96 . GHs are widely used outside Europe to stimulate milk production in dairy cows and as a general...

Fast liquid chromatography

Basic approaches to fast LC are very similar to fast GC approaches presented in Table 1. Of course, differences exist due to a simple fact LC employs liquid not gaseous mobile phases. Apart from different physico-chemical properties of the mobile phase, LC is much more versatile technique than GC because both stationary and mobile phase affect the separation. A myriad of stationary and mobile phase combinations can be used, enabling selectivity optimization for enhanced separation and or...

Iontrap mass spectrometers

The conventional 3D ion-trap (Paul trap) mass spectrometer has only three electrodes, one ring electrode between two hyperbolic endcap electrodes, which form a three-dimensional trap. The oscillating potential difference established between the ring endcap electrodes forms a substantial quadrupolar field. The ions can be stored for milliseconds or longer in an ITD. Raising the DC potential will isolate ions of a particular m z by ejecting all of the other ions from the trap. A subsequent...

Linear ion trap

The LIT mass spectrometer, a recent addition to the MS family, has increased ion capacity, improved ion trapping efficiency and faster cycle times compared Figure 4 GC-MS MS chromatograms of mono-ortho PCBs fraction for a vegetable oil sample with (a) problems in the clean-up process (b) suitable clean-up process. Reproduced from Ref. 75 with permission. Figure 4 GC-MS MS chromatograms of mono-ortho PCBs fraction for a vegetable oil sample with (a) problems in the clean-up process (b) suitable...

Liquid chromatography

One of the disadvantages of GC has always been, and in fact still is, the requirement that the compound to be determined has to be thermally stable and should have a sufficient volatility. In GC analysis, these compounds either show sign of thermal decomposition or fail to elute to column. In recent years many new pesticides have been developed that are not very well amenable to GC. Among the analytical approaches, LC is the preferred separation technique for the most polar and thermally labile...

Agonists

B-agonists, the so-called -sympathomimetics, are characterized by their structural and pharmacological properties, which are very close to those of catecholamines. These drugs are used as bronchodilators, tocolytics or heart tonics in human and veterinary medicine. During the past 20 years, several studies focused on the effects of such synthetic molecules on growth rate and performances, when administered per os, mixed with feedingstuffs. From 1984, it was pointed out that a specific...

Selected applications

3.2.6.1 Multi-residue screening of pesticides in vegetables, fruit and baby food applying SBSE. An MRM has been described based on SBSE followed by capillary GC-MS using retention-locked conditions 4 . The method provides detection from the mg kg (ppm) to the sub mg kg (ppb) level hereby complying with the MRL set by regulatory organizations for pesticides in different matrices. A schematic overview of the original method is presented in Figure 12. Approximately 15 g of a vegetable, fruit or...

Issues according to the Rapid Alert System for Food and Feed

The Rapid Alert System for Food and Feed (RASFF) is primarily a tool for exchange of information between food and feed authorities in the European Union (EU) member states in cases where a risk to human health has been identified and measures have been taken, such as withholding, recalling, seizure or rejection of the products concerned. The European Commission (EC) publishes weekly overviews of RASFF alert and information notifications on its website, and the summarizing annual reports provide...

Enzymebased immunoassays EIAs

Whereas RIAs use radioactivity to measure the concentration of analyte, EIAs typically use a change in color, emission of light, or other signal. Specific equipment is required to quantify the amount of enzyme present by measuring the signal change that occurs. EIAs offer numerous advantages over other immunotechniques because their signal is amplified by forming a great amount of product molecules, and they are widely used for food purposes, especially those based on heterogeneous conditions,...

Capillary electrophoresis

CE is an analytical technique more and more extensively used in food analysis. It is generally used as a chromatographic technique, where mycotoxins are separated from one another and from matrix components using electrical Figure 10 Total ion chromatogram obtained after clean-up with MycoSeps 226 columns and LC-MS-MS analysis of a spiked maize sample containing 100 mg kg of each mycotoxin. Vertical lines illustrate change of ionization polarities from negative to positive (5.4 min) and back to...

Hapten synthesis

Small molecules, such as most food contaminants, with molecular weights lower than 5,000-10,000 do not elicit immune responses. In those cases, the molecules are named haptens because it is necessary to attach them to a large carrier protein in order to stimulate the immune response. Sometimes, the hapten is used as detector, then it is attached to an enzyme. In both cases, as immunogen, or as detector, the attachment to the protein is through a covalent bond, and a linker or spacer arm is...

Determination of volatile nitrosamines

Volatile nitrosamines are usually determined by gas chromatography (GC) with detection by thermal energy analysis (TEA). A review by Hotchkiss in 1981 62 summarizes early methods of analysis and should be consulted for the relevant references. The analytical strategy includes the addition of di-n-propyl nitrosamine, which does not occur naturally, as an internal standard and of SA and a mineral acid (the ''stopping solution'') to prevent artifactual nitrosation. The first step in an early...

Gel permeation chromatography

For fatty food matrices, the main problem is the co-extraction of fats. The amount of fat extracted strongly depends on the nature of the target solutes and the solvent to be selected to efficiently extract them. For example, the determination of PCBs in meat requires extraction with an apolar solvent like cyclohexane that will solubilize the fat completely while extraction of phenylurea pesticides can be performed with acetonitrile, only partly solubilizing the fat. When the fat content is...

Cases of acute mycotoxicosis in humans

Over past centuries the presence of mycotoxin, mainly aflatoxin and trichothe-cenes in food, has been reported to recurrently cause outbreak of acute intoxication even resulting in death. The most recent was reported in 2004 in eastern Kenya, where, due to aflatoxin contamination of home-grown maize, 317 cases of acute hepatic failure were identified with 125 cases occurring in persons who subsequently died. The case-control study conducted by Azziz-Baumgartner et al. in 2005 68 proved that...

Timeofflight mass spectrometry

The current trend in the trace analysis of food contaminants and residues is to use TOF-MS systems because they are easier and less expensive to operate compared with the other high resolution and high accuracy mass spectrometers 5,37-41 . Recent advances have reduced instrument costs and have made analysis less complicated, more accurate and more quantitative 15 . At present, several commercial benchtop instruments are available with high resolution and accurate mass that are suitable for food...

Sample preparation

The tremendous growth observed in previous years in the number of papers dealing with the determination of the BFR in different environmental and biological matrices has developed a wide variety of analytical approaches for both sample preparation and instrumental analysis. There are already several reviews 43-47 that pointed out these progresses. For PBDEs, analytical procedures have been derived from previously established protocols based on gas chromatography-mass spectrometry (GC-MS) for...

Occurrence of volatile nitrosamines

Figure 1 shows the structures of many of the nitrosamines that can occur in foods. In general, NOC appear to accumulate in foods that are fermented and or stored for long periods at ambient temperatures, e.g., beer and fish sauce. In the late 1960s, fried bacon was found to contain up to 100 mg kg (ppb) of volatile nitrosamines, especially NDMA and NPYR 152,153 . In 1972 a group that included the author found that ascorbic acid (vitamin C) inhibited nitrosamine formation in chemical systems 19...

A

Class Typical pesticide Chemical structure Substituted phenol 2-Phenylphenol addition, transport of residues and sediment may also contaminate drinking water sources 2 . Dietary exposure to a pesticide depends on both the actual residue in or on foods and the food consumption pattern. In determining the health risks associated with chronic intake, it is necessary to determine the quantity of the pesticides likely to be consumed over a prolonged period of time and compare this estimate with the...

Steroids

Monitoring programs to control their use are frequently based on the initial screening of animals for steroid abuse using chemical or immunochemical methods 2,3 , followed by the complete chemical confirmation of steroids in suspect samples by mass spectrometry (MS) 4-12 . Urine and hair samples are normally ad hoc matrices since they are readily available at both abattoir and farm. Until recently, the standard technique for steroid analysis has been gas chromatography (GC)-MS. This required...

Essential and nonessential elements

It is impossible to establish a clear distinction between essential and non-essential (toxic) elements, since all metals are probably toxic if ingested in sufficient amounts. However, even if this aspect is beyond the aim of this discussion, some consideration may be given. In a very interesting work, Wolf 1 discussed, in a qualitative way, the relationship about the elements, their recommended dietary allowance, adequate intake and recommendations. The fundamental four points described in this...

Pesticides of new generation

Recently, several applications have described the use of MS-MS with both QqQ and IT analysers in multiresidue analysis of pesticide 97,115-117 . Most of the methods achieve satisfactory results even without making use of clean-up treatments. Sannino et al. 117 described a sensitive and selective method for the determination of 24 new pesticide residues (azoxystrobin, trifloxystrobin, kresoxim-methyl, fenazaquin, indoxacarb, fenothiocarb, furathiocarb, benfura-carb, imidachloprid, dimethomorph,...

Eu Legislation

Regulation (EC) No 178 2002 prod DocNumber& 1g en& type_doc Regulation& an_doc 2002& nu_doc 178). Regulation (EC) No.852 2004 prod DocNumber& 1g en& type_doc Regulation& an_doc 2004& nu_doc 852). Regulation (EC) No 853 2004 prod DocNumber& 1g en& type_doc Regulation& an_doc 2004& nu_doc 853). Regulation (EC) No 854 2004 prod DocNumber& 1g en& type_doc Regulation& an_doc 2004& nu_doc 854). Regulation (EC) No 882 2004 prod DocNumber& 1g en&...

Water quality

The Directive 75 440 EEC claims that surface water shall be assumed to conform to the relevant parameters if samples of this water taken at regular intervals at the same sampling point and used in the abstraction of drinking water, show that it complies with the parametric values for the water quality in question, in the case of 95 of the samples for parameters conforming to those specified and 90 of the samples in all other cases, and if in the case of the 5 or 10 of the samples which do not...

Classes Of Mycotoxins

Mycotoxins represent a quite wide spectrum of chemical compounds characterized by different molecular structures as a result of the numerous species of fungi responsible for their production. Major and minor classes of mycotoxins can be distinguished among major class aflatoxins, ochratoxins, trichothecenes, FBs, patulin and zearalenone represent the most concern for human and animal health, while in the minor class, ergot alkaloids, citrinin, cyclopiazonic acid, sterigmatocystin, moniliformin,...

Effects of low doses of mycotoxins

By considering the overall low frequency of outbreaks of acute intoxication and the worldwide reported high rate of occurrence of mycotoxins at low concentration in food, it can be concluded that it is likely that the population is worldwide generally exposed to low doses of mycotoxins over long periods and consequently that most of the toxic effects exerted by mycotoxins are chronic. According to Kuiper-Goodman 67 and as far as chronic disease is concerned, the risk attributable to the...

Paper and board

Paper and board are made of mixtures of materials from different sources and may therefore contain printing inks, adhesives, trace elements, waxes, fluorescent whitening agents and dyes, sizing agents, organochlorine substances, plasticizers, aromatic hydrocarbons, volatile organic compounds, curing and grease-proofing agents, amines, biocides, surfactants and all sorts of degradation products 33 . Nerin et al. 34 evaluated the use of Porapak as a solid-food simulant to assess the safety of...

Introduction To Eu And Usa Legislation

Over the past 15 years a series of food safety crises (Bovine Spongiform Encephalopathy (BSE), dioxins, high pesticide and antibiotic content in several foods, high nitrates content, presence of coliforms in drinking water, usage of Sudan Red 1 and formation of acrylamide among others) occurred within the frame of European Union (EU) thus resulting in great losses of human lives and capital. These crises made EU citizens more alert but also increased considerably the EU legislative task in an...

GCTEA of methyl esters of nitrosamino acids

This is now the preferred method for determining nitrosamino acids such as NPRO, because it is more rugged, more sensitive and simpler to use than HPLC-TEA 13 . The analysis of poorly volatile nitrosamines, including nitrosamino acids, was reviewed by Massey 14 , Sen and Kubacki 13 and Tricker et al. 11 . In 1981, Ohshima and Bartsch 88 reported that NPRO occurred in the urine of a subject who ingested nitrate and the amino acid l-proline. NPRO formation is a useful test because it may indicate...

Methods for the Determination of NNitroso Compounds in Food and Biological Fluids

Physical and Chemical Properties of NOC 656 2.1 UV, nuclear magnetic resonance NMR and mass spectrometry MS 656 2.2 Synthesis, formation and decomposition of NOC 657 4.3 General considerations in NOC analysis 660 4.4 Determination of volatile nitrosamines 661 4.5 HPLC-TEA of nitrosamino acids 665 4.6 GC-TEA of methyl esters of nitrosamino acids 665 4.7 GC-TEA of hydroxyalkylnitrosamines 667 4.8 HPLC-photolysis-TEA of non-volatile NOC 669 4.9 Havery's HPLC-TEA method for all types of NOC 669...

Introduction

Phytoplankton are microalgae and are the main contributor to the marine food web as well as oxygen on earth. The beneficial role of algae in the food chain arises from the fact that they are the only organisms that can readily make long chain polyunsaturated fatty acids PUFAs . Shellfish feed on phytoplankton and the potential beneficial role of shellfish in the human diet has been attributed to the presence of oils that are rich in PUFAs. Shellfish are also a rich source of protein, essential...

Cleanup step

The main clean-up procedures are liquid liquid partition, solid phase extraction SPE and multifunctional solid phase extraction Mycosep SPE . Polar, nonpolar and ion exchange-based SPE are commercially available. Mycosep cartridge is packed with different adsorbent material with the aim to retain particular groups of compounds that may create interferences in analytical methods. Multifunctional SPE columns allow mycotoxins to pass through aiming to remove the interferences from the sample. A...

Furan

Furan CAS 110-00-9, C4H4O, M.W. 68.07 is a cyclic dienyl ether with a low boiling point bp760 31 C and is poorly soluble in water. Its industrial uses are mainly focused on synthetic purposes. Furan shows carcinogenic properties in rodents and has thus been classified by IARC as class 2B, i.e., as possibly carcinogenic to humans 106 . The European Food Safety Authority EFSA has recently reviewed the toxicity data on furan and found that the weight of evidence indicates that furan-induced...

ExOfficials of Chemical Testing Lab Found Guilty of Falsifying Results

CHICAGO, Oct. 21 Three former officials of Industrial Bia-Test IBT Laboratories, once . widely used by government and. industry to test thousands of new chemicals for safety, were convicted today of falsifying results of four chemical tests. A US. District Court jury found thetn guilty of mail fraud and making false statements to the government, ending a protracted federal investigation into the efficacy of tox-icological te.f ts peformed by the Northwood, ill., firm. IBT once was considered...

Specific examples of recent methodology

In the next section, a few specific important examples are examined in more detail. These include methods for the analysis of sulfonamides in milk and dairy products, chloramphenicol in shellfish, nitrofurans in various foods and triphenylmethane dyes in farmed fish and shrimp. 4.3.1 Sulfonamides in dairy products Sulfonamide residues in dairy products have been a regulatory issue for a long time. These drugs effectively treat bovine mastitis and can then be transferred into the cow's milk....

PBDEs and PBBs

The most applied analytical method for PBDEs is GC-MS. One of the most crucial steps of the analysis is the injection of the extract into a GC system. The GC column then separates the different PBDE congeners from each other and from interferences that are eventually present in the extract. Finally, the analytes are detected, identified, and quantified using MS. 2.2.1.1 GC injection. The most frequently used injection techniques for PBDEs and PBBs are splitless, on-column injection and...

Medium volatiles and nonvolatiles organic substances

Clean-up from the food matrix can be attempted in a variety of ways Selective solvent extraction the food sample is extracted with a solvent selected to dissolve the target substance but not the main food matrix. Solvent-solvent partitioning the food extract is partitioned washed with a second solvent to remove potential interferences. Size exclusion chromatography SEC or gel permeation chromatography GPC can be used to determine and isolate fraction of target substances that have a molecular...

Food quality

The aim is to provide advice for schemes of best practice and help consumers by promoting best practice amongst assurance schemes. It covers relevant legislation, advice on the setting and delivery of production standards and Table 7 Directives main points and comments dealing with packaging force 19 6 1976 Approximation of the laws of the Member States relating to the making-up by volume of certain prepackaged liquids Application to packages containing liquid products, measured by volume and...

Volatile organic substances

Clean-up from most food matrices can be achieved effectively by headspace static or dynamic , or purge and trap sampling techniques e.g., Tenax . The food sample is heated and the volatile components are partitioned into the headspace gas leaving the main food components behind. An aliquot of the headspace is then injected into the GC column. In some cases solid-phase microextraction SPME has been applied. GC-MS is often preferred due to the possibility to monitor specific ions which lead to an...

Commercial Instrumentation And Future Perspectives

The majority of reported biosensor research has been directed towards the development of devices for clinical markets however, driven by the need for better methods for food surveillance, research into this technology is also expanding to encompass food applications. Table 6 shows some examples of commercial biosensor instrumentation available for toxic compounds and pathogens analysis in food. A number of instruments for food analysis are already commercially available. However, the commercial...

Acrylamide Chloropropanols and Chloropropanol Esters Furan

Stadler and Till Goldmann 2.3 General considerations on MCPD-esters 2.4 Proficiency tests and collaborative studies 3.3 Proficiency tests and monitoring exercises Acrylamide 2-propenamide, CH2 CHCONH2, CAS Registry Number 79-06-01, M.W. 71.08 is a colourless, odourless, and highly water soluble 215 g L at 25 C crystalline compound with a melting point of 84.5 C. Acrylamide is an important industrial chemical used since the mid-1950s to produce water-soluble polyacrylamides employed...

Determination and detection 531 Chromatographic methods

Gas Chromatogram

5.3.1.1 High-performance liquid chromatography. A wide variety of methods for most mycotoxins are based on HPLC, which is the methodology of choice for aflatoxins, OTA, ZEA, FBs and patulin. The HPLC separation is followed by fluorescence detection for aflatoxins, OTA, ZEA and FBs, usually as derivative compounds. UV detection is used for DON and patulin determination. Advantages of HPLC determination include excellent performance characteristics, low detection levels as low as 0.1 ng g and...

Ld50-acenaphthene

3.1 Effects on laboratory mammals in vitro The biological mechanisms to produce adverse effects of the majority of PAHs are not well understood yet. Except for Naph, there are only a limited number of studies available for the evaluation of acute oral toxicity. The values of oral LD50 Benz a anthracene3 Benzo gt fluoranthene B a A B gt F Benzo fluoranthene Benzo c fluoranthene Benzo g 7 ' fluoranthene Benzo g 7 ' perylene Coronene Cyclopenta ccf pyrene Dibenz a, 7 anthracene Dibenzo ae pyrene...

TTC principle

The toxicological characteristics of substances on the positive list are normally obtained through time-consuming and expensive toxicity testing. For example, petitioning of FCMs, require least three mutagenicity tests. From a practical and economic point of view, it is not feasible that these tests should also be carried out for all unlisted substances which may be present in migration extracts. To circumvent this problem the FDA has already introduced the ToR 23,55,56 . Based on a large...

Example functional group assay for aromatic amines

At TNO Toegepast Natuurwetenschappelijk Onderzoek , Dutch center for Applied Research, a functional group assay based on chemical derivatization and GC-MS analysis was developed that specifically assigns aromatic amines, i.e., compounds with a structural alert for genotoxicity, in complex mixtures. The requirements of the derivatization procedure must meet the following criteria it must be specific for aromatic amines and the fragmentation behaviour under EI conditions must generate a common...