Making complex measurements of meat composition fast: Application of rapid evaporative ionisation mass spectrometry to measuring meat quality and fraud.

Increasing demands are being placed on meat producers to verify more about their product with regards to safety, quality and authenticity. There are many methods that can detect aspects of these parameters in meat, yet most are too slow to keep up with the demands of modern meat processing plants and supply chains. A new technology, Rapid Evaporative Ionisation Mass Spectrometry (REIMS), has the potential to bridge the gap between advanced laboratory measurements and technology that can screen for quality, safety and authenticity parameters in a single measurement. Analysis with REIMS generates a detailed mass spectral fingerprint representative of a meat sample without the need for sample processing. REIMS has successfully been used to detect species fraud, detect use of hormones in meat animals, monitor meat processing and to detect off flavours such as boar taint. The aim of this review is to summarize these and other applications to highlight the potential of REIMS for meat analysis. Sampling methods and important considerations for data analysis are discussed as well as limitations of the technology and remaining challenges for practical adoption.

An RNA-aptamer-based assay for the detection and analysis of malachite green and leucomalachite green residues in fish tissue.

A robust screening assay employing solid phase extraction (SPE) followed by a novel aptamer-based procedure is presented for the rapid detection and semiquantitation of the triphenylmethane dye, Malachite Green (MG) and its primary metabolite Leucomalachite Green (LMG) in fish tissue. To the authors' knowledge, this is the first reported use of an RNA aptamer for the development of a diagnostic assay for the detection of chemical residues in food. The aptamer based screening assay is found to be highly specific for MG; but has negligible affinity for the LMG metabolite. However, because the LMG metabolite is lipophilic and known to be highly persistent in tissues, an oxidation step has been incorporated within the sample cleanup procedure to ensure that all LMG residues are converted to MG prior to measurement. This article provides evidence that an oligonucleotide aptamer can be used as an alternative recognition element to conventional antibodies with application to the detection of residues in food. Furthermore, this finding has the future potential to reduce the number of animals currently being used in the production of antibodies for immunodiagnostic kits.

Development and validation of an optical SPR biosensor assay for tylosin residues in honey.

In recent years there has been an increase in the use of tylosin in apiculture as bacterial brood diseases become resistant to oxytetracycline. Confirmatory mass spectrometry based methods have been developed but up until now there has been no complementary screening method available capable of sub 10 microg kg(-1) detection limits. In this paper the development and validation of a screening method using optical biosensor technology is presented. The honey was first dissolved in a phosphate buffer and following solid-phase extraction (SPE) cleanup was analyzed using a Biacore Q instrument. Using the criteria specified in European Commission Decision 2002/657/EC for qualitative screening methods, the detection capability (CCbeta) of the method was determined to be 2.5 microg kg(-)(1). Honey samples containing trace residue levels of tylosin were analyzed by both the biosensor screening method and a LC-MS/MS confirmatory procedure; the results were in good agreement.

Evaluation and validation of an accurate mass screening method for the analysis of pesticides in fruits and vegetables using liquid chromatography-quadrupole-time of flight-mass spectrometry with automated detection.

This study reports the development and validation of a screening method for the detection of pesticides in 11 different fruit and vegetable commodities. The method was based on ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-QTOF-MS). The objective was to validate the method in accordance with the SANCO guidance document (12571/2013) on analytical quality control and validation procedures for pesticide residues analysis in food and feed. Samples were spiked with 199 pesticides, each at two different concentrations (0.01 and 0.05 mg kg(-1)) and extracted using the QuEChERS approach. Extracts were analysed by UPLC-QTOF-MS using generic acquisition parameters. Automated detection and data filtering were performed using the UNIFI™ software and the peaks detected evaluated against a proprietary scientific library containing information for 504 pesticides. The results obtained using different data processing parameters were evaluated for 4378 pesticide/commodities combinations at 0.01 and 0.05 mg kg(-1). Using mass accuracy (± 5 ppm) with retention time (± 0.2 min) and a low response threshold (100 counts) the validated Screening Detection Limits (SDLs) were 0.01 mg kg(-1) and 0.05 mg kg(-1) for 57% and 79% of the compounds tested, respectively, with an average of 10 false detects per sample analysis. Excluding the most complex matrices (onion and leek) the detection rates increased to 69% and 87%, respectively. The use of additional parameters such as isotopic pattern and fragmentation information further reduced the number of false detects but compromised the detection rates, particularly at lower residue concentrations. The challenges associated with the validation and subsequent implementation of a pesticide multi-residue screening method are also discussed.

A generic method for the quantitative analysis of aminoglycosides (and spectinomycin) in animal tissue using methylated internal standards and liquid chromatography tandem mass spectrometry.

Aminoglycosides (AGs) are a large and diverse group of antibiotics. Although AGs may cause side effects of nephrotoxicity and ototoxicity, they are still occasionally being used for the treatment of serious infections. In this study the development of a method is described for the quantitative determination and confirmation of seven aminoglycosides (and relevant isomers) and spectinomycin in animal tissues. The extraction was based on an extraction followed by a concentration and clean-up step using weak cation exchange solid phase extraction. The separation was performed by ion-pair liquid chromatography on a C(18) column followed by mass spectrometric detection. The method was validated according to the EU requirements for a quantitative confirmatory method. Permethylated aminoglycosides (in-house synthesised internal standards) were used for accurate quantification. The accuracy of the analyses of AGs in kidney ranged from 94 to 111%, intra-day precision ranged between 2.5 and 7.4% (R.S.D.(r)) and inter-day precision ranged between 2.2 and 17.3% (R.S.D.(RL), n=21, MRL level). Accuracy (muscle tissue) varied from 83 to 128% with an intra-day precision between 2.2 and 17.3% (R.S.D.(r), n=7, MRL level). From the results it was concluded that the method was able to monitor MRL levels which ranged from 750 to 20,000 microgkg(-1) for kidney and from 50 to 10,000 microgkg(-1) for muscle tissue.