Profiling of volatile substances by direct thermal desorption gas chromatography high-resolution mass spectrometry for flagging a characterising flavour in cigarette tobacco

This paper describes an analytical method that supports the implementation of articles 9 and 10 of the WHO Framework Convention on Tobacco Control (FCTC) regarding the provisions on the reduction of the palatability and attractiveness of tobacco products regarding flavour ingredients. This study aimed to develop a screening method to identify cigarettes that may have a characterising flavour to support the implementation of the ban of characterising flavours of tobacco products, as laid down in the US and EU law. An analytical method combining direct thermal desorption and GC-QTOF MS was developed for acquiring the profile of volatile and semi-volatile substances in tobacco. A database of flavour additives was created comprising 133 compounds. A group of cigarettes without a declared characterising flavour was used to establish a reference profile of flavouring chemicals commonly present in tobacco products. A reference profile was modelled both by the means of principal component analysis (PCA) and based on the calculation of threshold values specified as 95th percentile of measured compounds' relative responses. Cigarettes and roll-your-own tobacco labelled as flavoured were analysed to evaluate the discrimination power of the method. A constructed model of the reference cigarettes allowed the differentiation of the flavoured tobacco products from the reference group. The method allows drawing conclusions on the chemical profiles of flavour constituents of tobacco products at even sensorial subliminal concentration levels and is suitable for both the initial screening of products on the market for characterising flavours and for confirmatory purposes after sensory analysis.

Influence of battery power setting on carbonyl emissions from electronic cigarettes

INTRODUCTION

Although e-cigarettes share common features such as power units, heating elements and e-liquids, the variability in design and possibility for customization represent potential risks for consumers. A main health concern is the exposure to carbonyl compounds, which are formed from the main components of e-liquids, propylene glycol and glycerol, through thermal decomposition. Levels of carbonyl emissions in e-cigarette aerosols depend, amongst others, on the power supplied to the coil. Thus, e-cigarettes with adjustable power outputs might lead to high exposures to carbonyls if the users increase the power output excessively. The aim of this work was to elucidate the generation of carbonyls in relation to undue battery power setting.

METHODS

Carbonyl emissions were generated by two modular e-cigarettes equipped with two atomizers containing coils of different resistance following the ISO 20768:2018 method. The battery power output was increased from the lower wattage level to above the power range recommended by the producer. Carbonyls were trapped by a 2,4-dinitrophenylhydrazine (DNPH) solution and analysed by LC-MS/MS.

RESULTS

The amount of carbonyl emissions increased with increasing power setting. An exponential incline was observed when the applied power level exceeded the recommended power range. Exceeding the recommended power range by just 5 watts resulted in up to twenty times the amount of carbonyls emitted at the recommended upper power level. Generation of acetaldehyde and acrolein next to other carbonyls was prominent at high power outputs.

CONCLUSIONS

E-cigarettes with customisable power setting might generate high amounts of carbonyls if the battery power output is set by the consumer to levels above the recommended range. This represents a high risk of exposure to carbonyls and thus should be avoided by integrating safety features in e-cigarette devices to limit the possible power settings to the range specified by the manufacturer.

Validation by collaborative trial of a method for the determination by GC-MS and LC-MS/MS of boar taint marker compounds in pork tissue

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Simultaneous determination of indole, skatole, and androstenone in pork tissue.

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Sensorial thresholds are within working ranges of the method.

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Choice of sample measurement by GC–MS or LC–MSMS.

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Method validation by collaborative trial with participants from 10 countries.

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Method performance parameters are compliant with EU legislation on food contaminants.

Meat from male pigs may develop an off-flavour, commonly known as boar taint. Castration of male piglets prevents the potential formation of off-flavour.

In the suggested method, three marker compounds for boar taint (skatole, androstenone and indole) are quantified in pork fat by isotope dilution gas chromatography mass spectrometry (GC–MS) or by isotope dilution liquid chromatography tandem mass spectrometry (LC–MS/MS).

This method was validated by collaborative trial according to ISO 5725-2:1994. The studied concentration ranges included sensorial thresholds. The repeatability relative standard deviation (RSD_r) ranges from 3% to 10% and the reproducibility relative standard deviation (RSD_R) from 10% to about 30%.

The method has proven to be robust and free from matrix interferences.

The method performance characteristics are compliant with requirements for official control methods in the area of food contaminants; therefore, the method is regarded as fit for its intended purpose.

Identification of Cigarette Brands by Soft Independent Modeling of Class Analogy of Volatile Substances

INTRODUCTION

This study aimed to develop a method for discriminating cigarette brands based on the profiles of volatile components extracted from the tobacco fraction of the finished cigarettes to authenticate branded cigarettes of unknown origin.

METHODS

An analytical method comprising direct thermal desorption coupled with gas chromatography-quadrupole time-of-flight mass spectrometry was developed for acquiring volatile profiles of cigarettes. About 290 samples of commercially available cigarettes were analyzed. Within this batch, 123 samples represented four popular cigarette brands. They were selected for in-depth characterization. Multivariate analysis was used to investigate the interrelations among volatile compounds of cigarettes and to identify characteristic markers for the cigarette discrimination. Supervised pattern recognition techniques were used for designing classification models.

RESULTS

Principal component analysis covering all detected volatiles allowed the differentiation of cigarettes based on the brand. A number of 56 volatile components were identified as markers with high discrimination power. These compounds were used for establishing classification models. A method of soft independent modeling of class analogy developed for the four studied cigarette brands proved to be efficient in the classification of unknown cigarettes, with accuracy between 95.9% and 100%.

CONCLUSIONS

The data evaluation by soft independent modeling of class analogy was highly accurate in classification of unknown cigarettes with a low rate of false positives and false negatives. The developed models can be used for discrimination of genuine from non-genuine products with high level of probability.

IMPLICATIONS

Profiling of volatiles, which is commonly used for authentication of different food commodities, was applied for the characterization of cigarette tobacco for the purpose of authentication a cigarette brand. Volatile components with a high discrimination power were identified by means of multivariate statistical methods and used for establishing of a classification model. The classification model was able to discriminate genuine from non-genuine cigarettes with a high level of prediction accuracy. This model could be a powerful tool for tobacco control to judge the authenticity of cigarettes.

Results from Two Interlaboratory Comparison Tests Organized in Germany and at the EU Level for Analysis of Acrylamide in Food

After the publication of high levels of acrylamide (AA) in food, many research activities started all over the world in order to determine the occurrence and the concentration of this substance in various types of food. As no validated methods were available at that time, interlaboratory studies on the determination of AA in food were of the highest priority. Under the boundary conditions of applying well-established evaluation schemes, the results of 2 studies conducted by the Federal Institute for Risk Assessment (BfR) in Germany and by the European Commission's Directorate General Joint Research Center (JRC) exhibited an overall acceptable performance of the participants in these studies. Nevertheless, many laboratories showed problems in determining AA in food with a complex matrix such as cocoa. The results of analysis also showed a broader variation of AA for samples with low AA concentrations and indicated a bias of the results obtained by gas chromatography–mass spectrometry without derivatization. Improvements of the performance of some laboratories appeared to be necessary.

Overview of Acrylamide Monitoring Databases

Since high acrylamide levels in carbohydrate-rich food were reported in 2002, many research activities were started in order to gain knowledge on occurrence, formation, and prevention of this compound in food products. Among them, monitoring programs were conducted in many countries worldwide by official bodies as well as by the food industry. National and international bodies set up monitoring databases. In 2003, both the European Commission and the World Health Organization posted calls for data and placed their spreadsheets for the submission of data on the Web. The goal of the databases is to collect data for a reliable estimation of the exposure of consumers to acrylamide via the food chain. This paper describes the assessment of the data quality and outlines the composition of the data in the 2 databases, to date.

Evaluation of Results of an Interlaboratory Comparison Test on Determination of Acrylamide in Crispbread Samples

The European Commission's Directorate General Joint Research Centre has organized several proficiency tests on the determination of acrylamide (AA) in food. This paper presents the results and outcome of a proficiency test that focused on the determination of AA in crispbread samples. One of the goals was the identification of the influence of different parameters such as analyte extraction or instrument calibration on the analytical results. A set of samples, containing 3 different crispbread samples as well as extracts of one crispbread sample and AA standard solutions, was shipped to each participant. A total of 42 European laboratories reported analytical results that were evaluated by applying internationally accepted protocols and procedures. The study found that, for each sample, the results of 4–8 laboratories were outside the range formed by the target value plus or minus the 2-fold of the target standard deviation; thus, they did not perform satisfactorily. In transferring this knowledge to the data of monitoring databases of AA in food, care must be taken that data are quality controlled, as it is likely that some of them may be biased.

Experimental design-based isotope-dilution SPME-GC/MS method development for the analysis of smoke flavouring products

For the implementation of Regulation (EC) No 2065/2003 related to smoke flavourings used or intended for use in or on foods a method based on solid-phase micro extraction (SPME) GC/MS was developed for the characterisation of liquid smoke products. A statistically based experimental design (DoE) was used for method optimisation. The best general conditions to quantitatively analyse the liquid smoke compounds were obtained with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre, 60°C extraction temperature, 30 min extraction time, 250°C desorption temperature, 180 s desorption time, 15 s agitation time, and 250 rpm agitation speed. Under the optimised conditions, 119 wood pyrolysis products including furan/pyran derivatives, phenols, guaiacol, syringol, benzenediol, and their derivatives, cyclic ketones, and several other heterocyclic compounds were identified. The proposed method was repeatable (RSD% <5) and the calibration functions were linear for all compounds under study. Nine isotopically labelled internal standards were used for improving quantification of analytes by compensating matrix effects that might affect headspace equilibrium and extractability of compounds. The optimised isotope dilution SPME-GC/MS based analytical method proved to be fit for purpose, allowing the rapid identification and quantification of volatile compounds in liquid smoke flavourings.

Assessment of critical steps of a GC/MS based indirect analytical method for the determination of fatty acid esters of monochloropropanediols (MCPDEs) and of glycidol (GEs)

Fatty acid esters of 2- and 3-chloropropanediol (MCPDEs) and fatty acid esters of glycidol (GEs) are commonly monitored in edible fats and oils. A recommendation issued by the European Commission emphasizes the need of generating data on the occurrence of these substances in a broad range of different foods. So far, analytical methods for the determination of MCPDEs and GEs are fully validated only for oils, fats and margarine. This manuscript presents the assessment of critical steps in the AOCS Cd 29a-13 method for the simultaneous determination of MCPDEs and GEs in the fat phase obtained from bakery and potato products, smoked and fried fish and meat, and other cereal products. The trueness of the method is affected by the additional formation of 3-MBPD esters from monoacylglycerols (MAGs), which are frequently present in food. The overestimation of GE contents for some samples was confirmed by the comparison of results with results obtained by an independent analytical method (direct analysis of GE by HPLC-MS/MS). An additional sample pre-treatment by SPE was introduced to remove MAGs from fat prior to the GEs conversion, while the overall method sensitivity was not significantly affected. Trueness of the determination of GEs by the modified analytical procedure was confirmed by comparison with a direct analysis of GEs. The potential impact on accuracy of results of the final sample preparation step of the analytical procedure, the derivatization of free forms MCPD and MBPD with PBA, was evaluated as well. Different commercial batches of PBA showed differences in solubility in a non-polar organic solvent. The PBA derivatization in organic solvent did not affect precision and trueness of the method due to the isotopic standard dilution. However, method sensitivity might be significantly compromised.

Rapid and sensitive method for the determination of four EU marker polycyclic aromatic hydrocarbons in cereal-based foods using isotope-dilution GC/MS

A rapid and sensitive method has been developed for the determination of the four European Union marker polycyclic aromatic hydrocarbons (PAHs; benz[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene) in some cereal-based foods. The method is based on pressurised liquid extraction (PLE), solid-phase extraction clean-up (SPE) and isotope-dilution gas chromatography with mass-spectrometric detection (GC/MS). The developed method was calibrated for the content range of 0.05-12.5 µg kg(-1) (expressed on a product basis). Recoveries of PAH were monitored in each sample via the recovery of (13)C-labelled PAHs. Recovery values were in the range between 86% and 91%, with relative standard deviations (RSDs) between 5% and 9%. The achieved limits of detection for all analytes were below 0.05 µg kg(-1). The applicability of the method for the analysis of routine samples was studied by the analysis of a set of commercial bread and breakfast cereal samples. In all analysed samples, benzo[a]pyrene (BAP) was the most prevalent PAH with the content between 0.09 and 0.30 µg kg(-1). On average, samples showed low levels of the sum of the four EU marker PAHs (ΣPAH4) that ranged between 0.11 and 0.22 µg kg(-1) for bread samples and between 0.23 and 0.87 µg kg(-1) for breakfast cereal samples. The developed method was found suitable for the determination of PAHs in cereal-based foods like cornflakes and breads with total relative fat contents below 3.5%.

Single-laboratory validation of a saponification method for the determination of four polycyclic aromatic hydrocarbons in edible oils by HPLC-fluorescence detection

An analytical method is reported for the determination of four polycyclic aromatic hydrocarbons (benzo[a]pyrene (BaP), benz[a]anthracene (BaA), benzo[b]fluoranthene (BbF) and chrysene (CHR)) in edible oils (sesame, maize, sunflower and olive oil) by high-performance liquid chromatography. Sample preparation is based on three steps including saponification, liquid-liquid partitioning and, finally, clean-up by solid phase extraction on 2 g of silica. Guidance on single-laboratory validation of the proposed analysis method was taken from the second edition of the Eurachem guide on method validation. The lower level of the working range of the method was determined by the limits of quantification of the individual analytes, and the upper level was equal to 5.0 µg kg(-1). The limits of detection and quantification of the four PAHs ranged from 0.06 to 0.12 µg kg(-1) and from 0.13 to 0.24 µg kg(-1). Recoveries of more than 84.8% were achieved for all four PAHs at two concentration levels (2.5 and 5.0 µg kg(-1)), and expanded relative measurement uncertainties were below 20%. The performance of the validated method was in all aspects compliant with provisions set in European Union legislation for the performance of analytical methods employed in the official control of food. The applicability of the method to routine samples was evaluated based on a limited number of commercial edible oil samples.

The Occurrence of 16 EPA PAHs in Food - A Review

Occurrence and toxicity of polycyclic aromatic hydrocarbons (PAHs) have been extensively studied in countries all over the world. PAHs generally occur in complex mixtures which may consist of hundreds of compounds. The U.S. Environmental Protection Agency (EPA) proposed in the 1970 to monitor a set of 16 PAHs which are frequently found in environmental samples. This article reviews the suitability of the 16 EPA PAHs for the assessment of potential health threats to humans stemming from the exposure to PAHs by food ingestion. It presents details on analysis methods, the occurrence of PAHs in food, regulatory aspects, and related risk management approaches. In addition, consideration is given to newer evaluations of the toxicity of PAHs and the requirements for risk assessment and management stemming from them.

EU marker polycyclic aromatic hydrocarbons in food supplements: analytical approach and occurrence

Several food supplements comprising botanical, oil and bee products collected from retail markets in different countries were tested for the occurrence of 4 EU marker Polycyclic aromatic hydrocarbons (PAHs; benz[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene). A robust GC/MS-based stable-isotope dilution method was used taking into account the differences in the type of matrices. The accuracy of the results was assessed by implementing several quality control tools. Sixty-eight samples of 94 analysed products exceeded the level of 0.5 μg/kg for the sum of the four EU marker PAHs (ΣPAH4). Benzo[a]pyrene exceeded the limit of quantification in 49 samples. The PAH with the highest abundance in all products was chrysene. On average, propolis extracts and other bee products showed relatively high levels of ΣPAH4 (mean 188.2 μg/kg), whereas the contamination levels of fish oil supplements were very low or mostly undetectable. Considerably high ΣPAH4 amounts found in some samples could remarkably increase the daily exposure of consumers to PAHs, demonstrating the need for continuous monitoring of ΣPAH4 in food supplements.

Derivatization of bisphenol A and its analogues with pyridine-3-sulfonyl chloride: multivariate optimization and fragmentation patterns by liquid chromatography/Orbitrap mass spectrometry

RATIONALE

Due to the growing restrictions on the use of bisphenol A (BPA), several other bisphenols are gaining importance as substitutes for BPA in a variety of applications. There is, therefore, a real need for selective and sensitive methods based on mass spectrometry which will allow the human exposure to these new bisphenols to be assessed.

METHODS

Derivatization of BPA and its substitutes with pyridine-3-sulfonyl chloride is used to enhance the detection capability of bisphenols by electrospray ionization mass spectrometry. A multivariate experimental design, Box-Behnken response surface, was used to evaluate the influence of the main variables potentially affecting the derivatization yield. Fragmentation patterns for all the derivatized bisphenols were acquired by high-resolution/accurate-mass Orbitrap mass spectrometry.

RESULTS

Temperature and pH were identified as the most important factors affecting the derivatization yield of bisphenols. Fragmentation of the protonated molecules produced abundant analyte-specific product ions. Most of the derivatized bisphenols showed significant improvements in their signal-to-noise ratios compared with the underivatized forms. The stability of these derivatives was demonstrated through several freeze/thaw cycles, short-term room temperature and long-term cold storage.

CONCLUSIONS

Derivatization of BPA and its structural analogues with pyridine-3-sulfonyl chloride is proposed as a specific, sensitive, high-throughput approach to their analysis by liquid chromatography coupled to electrospray ionization mass spectrometry.

Analytical approaches for MCPD esters and glycidyl esters in food and biological samples: a review and future perspectives

Esters of 2 - and 3-monochloropropane-1,2-diol (MCPD) and glycidol esters are important contaminants of processed edible oils used as foods or food ingredients. This review describes the occurrence and analysis of MCPD esters and glycidol esters in vegetable oils and some other foods. The focus is on the analytical methods based on both direct and indirect methods. Methods of analysis applied to oils and lipid extracts of foods have been based on transesterification to free MCPD and determination by gas chromatography-mass spectrometry (indirect methods) and by high-performance liquid chromatography-mass spectrometry (direct methods). The evolution and performance of the different methods is described and their advantages and disadvantages are discussed. The application of direct and indirect methods to the analysis of foods and to research studies is described. The metabolism and fate of MCPD esters and glycidol esters in biological systems and the methods used to study these in body tissues studies are described. A clear understanding of the chemistry of the methods is important when choosing those suitable for the desired application, and will contribute to the mitigation of these contaminants.

Evaluation of the quality of postharvest rapeseed by means of an electronic nose

BACKGROUND

Rapeseed is a valuable source of edible oil. The presence of even a small amount of mouldy or burnt rapeseed in a particular production batch deteriorates the quality of the edible oil obtained from it. Since the traditional method of using a panel of experts is time-consuming, there is a need for fast and easy methods for rapeseed quality evaluation by intelligent devices to replace human labour.

RESULTS

For rapeseed quality evaluation, an electronic nose equipped with an array of eight quartz microbalance sensors and four metal oxide semiconductor sensors was used. Signals generated by the sensors were analysed by principal component analysis and discriminant function analysis. Identification of samples that contained small proportions of mouldy or burnt rapeseed was possible despite the differences between the particular varieties studied.

CONCLUSION

Electronic nose technology has shown the possibility of detecting samples of faulty rapeseed at very low contamination levels and distinguishing them with high probability from sound rapeseed.

Development and optimisation of a dopant assisted liquid chromatographic-atmospheric pressure photo ionisation-tandem mass spectrometric method for the determination of 15+1 EU priority PAHs in edible oils

European food legislation defines a set of 16 polycyclic aromatic hydrocarbons (PAHs) as of high concern for human health. The EU set contains structurally very similar PAHs with ring numbers between 4 and 6, and so raises some separation aspects and problems, which were not experienced with traditionally analysed PAHs. Many of the currently applied gas chromatographic mass spectrometric (GC-MS) methods suffer from separation problems, while high performance liquid chromatography with fluorescence detection (HPLC-FLD) is neither capable of detecting the whole set of EU priority PAHs nor does it (compared to GC-MS) allow structural identification. In addition HPLC-FLD shows limitations with difficult matrices due to interferences. The aim of this paper is to fill this gap by describing a liquid chromatographic dopant assisted atmospheric pressure photo ionisation tandem mass spectrometric (LC-DA-APPI-MS/MS) method for the determination of 15+1 EU priority PAHs in edible oil, which complies with the requirements set by European food legislation. Measurements were performed in positive ion mode. Anisole at a flow rate of 30 μl/min was used as dopant. Sample preparation was performed offline by donor-acceptor complex chromatography (DACC). Compared to HPLC-FLD methods the presented method enables the determination of all 15+1 EU priority PAHs at the low μg/kg concentration range including less fluorescence active compounds like benzo[j]fluoranthene and indeno[1,2,3-cd]pyrene. By analysing four reference materials it could be demonstrated that this method provides accurate results and is sufficiently sensitive for food control purposes. Statistically significant differences between the reference values and the measured analyte contents were not found. The method performs well also for very complex samples. Repeatability relative standard deviations (RSDr) of the determination of the target PAHs in olive oil were for most analytes below 5%. The limit of detection (LOD) of the method met the requirement set by EU legislation (0.3 μg/kg).

European Union database of acrylamide levels in food: update and critical review of data collection

The European Commission's Directorate General Joint Research Centre has been collecting data produced by European Union Member States on the acrylamide content of food since 2003. More than 9000 individual data points have been received from official food control laboratories directly or via their Competent Authorities, and from the food industry. Before being entered into the database, the data were assessed for their reliability. This paper presents an update of the database as well as results of the evaluation of data for selected food commodities in order to establish a trend concerning the content of acrylamide in food. Experience gained with the data collection and data assessment are described and recommendations for future data collection initiatives given.

Results of a European inter-laboratory comparison study on the determination of EU priority polycyclic aromatic hydrocarbons (PAHs) in edible vegetable oils

A collaborative study on the analysis for 15 + 1 EU priority PAHs in edible oils was organised to investigate the state-of-the-art of respective analytical methods. Three spiked vegetable oils, one contaminated native sunflower oil, and one standard solution were investigated in this study. The results of 52 laboratories using either high-performance liquid chromatography with fluorescence detection or gas chromatography with mass-selective detectors were evaluated by application of robust statistics. About 95% of the laboratories were able to quantify benzo[a]pyrene together with five other PAHs included in the commonly known list of 16 US-EPA PAHs. About 80% of the participants also quantified seven additional PAHs in most samples, two of which were benzo[b]fluoranthene and benzo[k]fluoranthene, which were also known from the EPA list. Only about 50% of the participants quantified cyclopenta[cd]pyrene, benzo[j]fluoranthene, and benzo[c]fluorene. The robust relative standard deviations of the submitted results without discrimination between the methods applied ranged between 100% for 5-methylchrysene in spiked olive oil and 11% for the same analyte in spiked sunflower oil. The results clearly showed that for these analytes the methods of analysis are not yet well established in European laboratories, and more collaborative trials are needed to promote further development and to improve the performances of the respective methods.

Analysis of heat-induced contaminants (acrylamide, chloropropanols and furan) in carbohydrate-rich food

Heat-induced food contaminants have attracted attention of both the scientific community and the public in recent years. The presence of substances considered possibly or probably carcinogenic to humans has triggered an extensive debate on the healthiness of even staple foods. In that respect, acrylamide, furan and chloropropanols are the main substances of concern. Their widespread occurrence in processed food, which concomitantly causes considerable exposure to humans, led either to the setting of maximum limits (for some chloropropanols) or at least the initiation of monitoring programmes in order to put risk assessment on a solid data basis. Acrylamide, furan and chloropropanols are small molecules with physicochemical properties that make their analysis challenging. Their amount in food ranges typically from below the limit of detection to hundreds of micrograms per kilo or even milligrams per kilo. However, a number of recently published scientific reports deal with the analysis of these substances in different kinds of food. The aim of this publication is to give an overview of analytical approaches for the determination of acrylamide, furan and chloropropanols in foodstuffs.

Acrylamide in coffee: Review of progress in analysis, formation and level reduction

This paper summarizes the progress made in understanding the formation of acrylamide in coffee, as well as potential reduction strategies, as presented during the joint CIAA/EC workshop on acrylamide, held in Brussels in March 2006. Currently, there are no concrete measures to reduce acrylamide concentrations in roast and ground coffee without appreciably changing the organoleptic properties of the product. Certain approaches, such as steam roasting, have been tried on a laboratory scale, albeit without affording a significant reduction. More work on the mechanisms governing the "loss" of acrylamide during storage of roast and ground coffee is warranted, and studies in this direction have been initiated. Finally, risk/benefit analysis must be addressed in a complex food such as coffee, known to harbour numerous health beneficial/chemoprotective compounds with antioxidant and antimutagenic properties.

Zentralnervöse Atemdepression als Komplikation der Behandlung des kongenitalen Glaukoms mit Brominidin-Augentropfen

We report the case of a premature newborn (gestational age 33 weeks) with congenital glaucoma. After a trabeculotomy high intraocular pressure persisted, leading to adjuvant treatment with timolol and--when the infant was 3 weeks old--with brimonidine. After the first application of topical brimonidine the infant developed such severe apnoeic spells that intubation and temporary ventilation were necessary. A review of the literature reveals that when used in young infants brimonidine eye drops can potentially have toxic effects on the central nervous system (e.g. respiratory depression). The use of topical brimonidine is therefore not advised in this age group.

Periphere analgetische Wirkung durch intraartikulär verabreichtes Clonidin

BACKGROUND AND AIM

Clonidine applied intra-articularly into the knee joint has a peripheral analgesic effect. We examined intra-articularly injected clonidine to determine whether resorption with a measurable systemic concentration could be detected.

METHODS

A randomised, placebo-controlled double-blind study was carried out on patients undergoing knee arthroscopies. The 69 patients were randomised into three groups: group 1 received 150 ug clonidine intra-articularly, group two 150 ug clonidine intravenously and group three a placebo. Postoperative pain therapy was carried out with i.v. morphine hydrochloride. Pain scores and side-effects were documented for 24 h.

RESULTS

There were no significant differences between the three groups in demographics, duration of operation, duration of anaesthesia, diagnoses or type of operation. The pain score at rest was significantly lower in group 1. In the first 20 min, the systemic concentration of clonidine was significantly higher in the intravenous group than in the intra-articular group.

CONCLUSION

Intra-articular clonidine has a postoperative analgesic effect after knee arthroscopies due to a peripheral action.

Anomalous origin of the left coronary artery from the pulmonary artery in a premature infant with preserved left ventricular function

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare condition. The majority of cases present with impaired left ventricular function. We report on a premature infant who was diagnosed at a gestational age near term with ALCAPA during routine cardiac examination. The patient showed no signs of myocardial ischemia and is doing well after corrective surgery. This is the youngest patient reported with ALCAPA and preserved myocardial function.

Investigation of the correlation of the acrylamide content and the antioxidant activity of model cookies

The purpose of this study was to evaluate the correlation between the acrylamide (AA) content and the antioxidant activity (AOA) of self-prepared cookies. Cookies were baked in the laboratory under defined conditions following four different recipes. The parameters of investigation were the influence of the type and relative content of sugar (glucose and fructose) and the baking time on the AA content as well as AOA of the final products. Parameters depending on the recipe and baking conditions such as the moisture content, the total nitrogen concentration, and the color of the products were evaluated for all samples as well. To prove the transferability of the findings gained with model cookies to samples from industry, the same measurements were performed on seven different types/brands of cookies that were purchased in local markets. A direct correlation was found between the concentration of AA and the AOA. With increasing baking time, the moisture content of the cookies decreased. The latter parameter correlated well with the AA concentration and AOA. The use of fructose enhanced the concentration of AA and the AOA of the final products, when compared with the use of sucrose. However, a simple model for the prediction of acrylamide contents and the AOA of samples from the baking time, color, protein, or moisture content of the samples was not found.

Evaluation of results of an interlaboratory comparison test on determination of acrylamide in crispbread samples

The European Commission's Directorate General Joint Research Centre has organized several proficiency tests on the determination of acrylamide (AA) in food. This paper presents the results and outcome of a proficiency test that focused on the determination of AA in crispbread samples. One of the goals was the identification of the influence of different parameters such as analyte extraction or instrument calibration on the analytical results. A set of samples, containing 3 different crispbread samples as well as extracts of one crispbread sample and AA standard solutions, was shipped to each participant. A total of 42 European laboratories reported analytical results that were evaluated by applying internationally accepted protocols and procedures. The study found that, for each sample, the results of 4-8 laboratories were outside the range formed by the target value plus or minus the 2-fold of the target standard deviation; thus, they did not perform satisfactorily. In transferring this knowledge to the data of monitoring databases of AA in food, care must be taken that data are quality controlled, as it is likely that some of them may be biased.

Chemometrical classification of pumpkin seed oils using UV-Vis, NIR and FTIR spectra

The main outcome of this work is elaboration of classification models for edible oil samples representing the most widespread brands of Austrian pumpkin seed oil. A complete spectral characterisation of the pumpkin seed oil samples by UV-Vis, NIR and FTIR spectra was obtained together with their basic sensorial classification. Chemometrical processing of the measured data enabled the detection of the most important spectral features, which are crucial for categorising the oils into two or three classes according to their sensory quality evaluated by a panel of experts. The elaborated models thus make it possible to predict the category into which a hitherto unclassified oil sample belongs--considering classification into either two categories, containing oils with overall acceptable scores or oils that were not accepted, or three categories, involving oils fulfilling all quality criteria, oils with good scores and not accepted oils. This will perspectively facilitate the determination of chemical substances responsible for bad taste, odour and colour of the respective oil brands, as well as finding substances contributing to the excellent sensorial perception of some tested products.

Results from two interlaboratory comparison tests organized in Germany and at the EU level for analysis of acrylamide in food

After the publication of high levels of acrylamide (AA) in food, many research activities started all over the world in order to determine the occurrence and the concentration of this substance in various types of food. As no validated methods were available at that time, interlaboratory studies on the determination of AA in food were of the highest priority. Under the boundary conditions of applying well-established evaluation schemes, the results of 2 studies conducted by the Federal Institute for Risk Assessment (BfR) in Germany and by the European Commission's Directorate General Joint Research Center (JRC) exhibited an overall acceptable performance of the participants in these studies. Nevertheless, many laboratories showed problems in determining AA in food with a complex matrix such as cocoa. The results of analysis also showed a broader variation of AA for samples with low AA concentrations and indicated a bias of the results obtained by gas chromatography-mass spectrometry without derivatization. Improvements of the performance of some laboratories appeared to be necessary.

Overview of acrylamide monitoring databases

Since high acrylamide levels in carbohydrate-rich food were reported in 2002, many research activities were started in order to gain knowledge on occurrence, formation, and prevention of this compound in food products. Among them, monitoring programs were conducted in many countries worldwide by official bodies as well as by the food industry. National and international bodies set up monitoring databases. In 2003, both the European Commission and the World Health Organization posted calls for data and placed their spreadsheets for the submission of data on the Web. The goal of the databases is to collect data for a reliable estimation of the exposure of consumers to acrylamide via the food chain. This paper describes the assessment of the data quality and outlines the composition of the data in the 2 databases, to date.