Food analysis simultaneous

Solid-phase sorbents are also used in a technique known as matrix solid-phase dispersion (MSPD). MSPD is a patented process first reported in 1989 for conducting the simultaneous disruption and extraction of solid and semi-solid samples. The technique is rapid and requires low volumes (ca. 10 mL) of solvents. One problem that has hindered further progress in pesticide residues analysis is the high ratio of sorbent to sample, typically 0.5-2 g of sorbent per 0.5 g of sample. This limits the sample size and creates problems with representative sub-sampling. It permits complete fractionation of the sample matrix components and also the ability to elute selectively a single compound or class of compounds from the same sample. Excellent reviews of the practical and theoretical aspects of MSPD " and applications in food analysis were presented by Barker.Torres et reported the use of MSPD for the... 

In foods, the simultaneous HPLC analysis of several vitamins is feasible only under special conditions, for example, determination of fortified, free vitamins rather than endogenous ones, which are often bound to other food components, or determination of vitamins in relatively simple foodstuffs, such as fruit juice. The HPLC separation per se of multiple vitamins is not difficult it is their simultaneous, nondegradative extraction from foods that is problematic. Developing a single set of extraction conditions that satisfies the diverse physicochemical properties and stability requirements of several vitamins is a challenge. 

Due to its versatility, robustness, and relativel low cost, ICP-AES has started to be considered as routine instrumentation for elemental composition measurements in many laboratories involved in food analysis. Unquestionably, the acceptance of the technique has been further advanced by the commercial availability of rapid, simultaneous, and flexible, sequential instruments based on echelle grating crossed dispersion and solid state detectors. It is expected that novel nebulizer devices for liquid sample introduction will find increased applications in beverage analysis. 

Another advantage offered by ICPs is that the eleetroehemieal synthesis allows the direet deposition of the polymer on the electrode surfaee, while simultaneously trapping the protein molecules. It is thus possible to control the spatial distribution of the immobilized enzymes, the film thickness and modulate the enzyme activity by changing the state of the polymer. Because of these ICPs have been used in the fabrication of biosensors in various fields such as Health eare, immuno sensors, DNA sensors, environmental monitoring, and food analysis. 

SBSE can be successfully used in the analysis of environmental samples [93-97] and for food analysis [98, 99]. PDMS is the most commonly used polymer, primarily because of its thermal stability and durability. SBSE has been modified by application of derivatization with different reagents (acetic anhydride, BSTFA, etc) [100-104]. This approach is suitable for the extraction of compounds requiring derivatization. The use of multistep derivatization with several extraction elements (each reaction is performed on a different stir bar) allows efficient extraction, desorption, and chromatographic analysis of compounds with different functional groups (e.g., phenols, steroids, amines, thiazoles, ketones). Acetic anhydride (ester formation), ethyl chloroformate (reaction of acids and amines), tetraethyloborane, and sodium bis-trimethylotrifluoroacetamide have been used for extraction and simultaneous derivatization [105]. 

New trends in the analysis of food contaminants in general focus on the simultaneous detection of different analytes present in the same sample. A multiplex PCR assay has been developed for the simultaneous detection of wheat, buckwheat, and peanut (Hashimoto et al., 2007). A distinct amplicon size for each allergen can be observed in an agarose gel. Since some RT-PCR thermocyclers have the ability to detect several fluorescent probes, they can easily be adapted to detect several food allergens simultaneously. Moreover, other platforms commonly used for multiplexing can be used in combination with PCR. Microarray slides can be spotted with peptide nucleic acid (PNA) capture probes for PCR products obtained from the amplification of DNA... 

Ito Y, Oka H, Dcai Y, et al.. Application of ion-exchange cleanup in food analysis V. Simultaneous determination of sulphonamide antibacterials in animal liver and kidney using high performance liquid chromatography with ultra violet and mass spectrometric detection, J. Chromatogr. A 2000 898 95-102. 

A special publication of the Royal Society of Chemistry on Magnetic Resonance in Food Science discusses many aspects of the use of conventional and less conventional NMR methods in food analysis (such as oil, meat, beer, wine, moisture in biopolymers) including multivariate analysis of time domain NMR (TD-NMR) °, the use of an NMR-MOUSE (mobile universal surface explorer) for portable NMR and a review of the challenges in transferring NMR technology to the on-line industrial situation . Quantitative analysis methods of mixtures of fatty compounds by H -NMR are reviewed. Rapid simultaneous determination by H NMR of unsaturation and composition of acyl groups have also been reported in vegetable oils. The use of IR, Raman, NMR, and MS was reviewed for the analysis of polysaccharides related to food. ... 

Application of infrared spectroscopy to food analysis has made possible the highly automated determination of protein content in foodstuffs. Available commercial instruments allow the simultaneous determination of water, lipid, fiber, and protein content in solid or liquid samples with little if any sample preparation and impressive throughput. 

One of the strengths of the NIR technique is its ability to provide the simultaneous determination of several constituents on the same sample. The determination of moisture was the first application of NIR in food analysis, and its importance warrants a whole chapter in this book. It is sufficient here to mention that the moisture content of bakers flour needs to be determined and that this may be accomplished concurrently with protein [3,7], Moisture has a strong absorption band at 1940 nm that is not overlapped by bands due to other constituents of flour (Figure 19.2) therefore calibration is straightforward because only a single reference wavelength (2310 nm) is required [9]. 

Chailapakul, 0 Korsrisakul, S Siangproh, W and Grudpan, K. (2008) Fast and simultaneous detection of heavy metals using a simple and reliable microchip-electrochemistry route an alternative approach to food analysis. Talanta, 15, 683-689. 

FIGURE 3.4 Distillation equipment used to isolate volatiles from foods (left high vacuum distillation of volatiles from an aqueous food right simultaneous distillation/extraction apparatus). (Reproduced from Guntert, M., G. Krammer, H. Sommer, P. Werkhoff, Flavor Analysis, C.J. Mussinan, M.J. Morello, Eds., Amer. Chem. Soc., Washington, D.C., 1998, p. 38. With... 

MSFIA chromatographic analysis was also applied to food analysis (Fernandez et ak, 2012), including orange juice, strawberry milkshake, and malt, for simultaneous determination of six water-soluble vitamins (thiamine, riboflavin, ascorbic acid, nicotinic... 

Shibata Y, Oyama M, Sato H, et al. 1998. Simultaneous cleanup method for multi pesticide residue analysis by GC and HPLC. J Food Hyg Soc Jpn 39(4) 241-250. 

Vinas, P., CampiUo, N., Hernandez Cordoba, M., and Candela, M. E. (1992). Simultaneous liquid chromatographic analysis of 5-hydroxymethyl-2-furaldehyde and methyl anthra-nilate in honey. Food Chem. 44, 67-72. 

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