Food and agricultural samples

This overview is focused on the on-line coupling of pressurized liquid extraction (PLE), microwave-assisted extraction (MAE), supercritical fluid extraction (SEE) and sonication-assisted extraction (SAE) with liquid and gas chromatography for the analysis of solid agricultural and food samples. In addition, head-space techniques and direct thermal extraction are discussed. 

Erbs, M., Hoerger, C.C., Hartmaim, N. and Bucheli, T.D. (2007). Quantification of six phytoestrogens at the nanogram per liter level in aqueous environmental samples using C-13(3)-labeled internal standards. Journal of Agricultural and Food Chemistry 55, 8339-8345. 

Brady J.F., J. Turner, and D.H. Skinner (1995). Application of a triasulfuron enzyme immunoassay to the analysis of incurred residues in soil and water samples. Journal of Agricultural and Food Chemistry 43 2542-2547. 

The former UK Ministry of Agriculture and Food has also published [17] recommended soil preparation techniques for the determination of a wide range of metals and for the preparation of plant samples for analysis by dry combustion and the determination of ash. 

Coker RD Design of sampling plans for determination of mycotoxin in food and feed in Sinha KK, Bhatnagar D (eds) Mycotoxin in Agriculture and Food Safety. New York, Dekker, 1998, pp 109-134. Wilson DM, Sydenham EW, Lombaert GA, Trucksess MW, Abramson D, Bennett GA Mycotoxin analytical techniques in Sinha KK, Bhatnagar D (eds) Mycotoxin in Agriculture and Food Safety. New York, Dekker, 1998, pp 135-182. 

Sommer AJ, Lang PL, Miller BS, Katon JE (1988) Application of molecular microspcctroscopy to paper chemistry. Prac Spectrosc 6 (Infrared Microspectrosc) 245-258 Sweeney KM (1989) FTIR microscopy of pulp and paper samples. Tappi J 72(2) 171-174 Wetzel DL (1983) Near-infrared reflectance analysis. Anal Chem 55 1165A-1176A Williams P, Norris K (1987) Near-infrared technology in the agricultural and food industries. 

ICP-MS appeared with the first prototypes in 1974, but diffusely it arrived on the international markets at the beginning of eighties. Nowadays, after several thousand instruments have been installed, it can be considered to be a mature and highly powerful technique. ICP-MS has the capability to analyze a wide range of elements in a variety of sample matrices. It is widely employed in Geological and Environmental Sciences, Semi-Conductor Industries, Material Science, Medicine, Agriculture, and Food and Beverages Sciences. 

The noninvasive nature of NMR spectroscopy combined with the chemical specificity of the NMR method provides direct access to the distribution of various chemical constituents for the histochemistry of plant materials in situ NMR spectroscopy can be used to identify the major constituents, and chemical-.shift imaging can be used to spatially localize them. The latter can be applied to localize aromatics, carbohydrates, as well as water and fat or oil in plant samples. The suitability of many fresh fruits and living plants to be studied by NMR imaging results in a variety of applications in agriculture and food science [Mcc I, Mcc2]. 

The sample collection and preparation has been carried out by the Agriculture and Food Development Authority in Wexford (Ireland) and the Institute for Reference... 

Figure 9.3. Sample preparation method proposed by Wong et al. for multiresidue analysis of pesticides in wine. (Reprinted from Journal of Agricultural and Food Chemistry 51, Wong et al., Multiresidue pesticide analysis in wines by solid-phase extraction and capillary gas chromatography-mass spectrometric detection with selective ion monitoring, p. 1150, Copyright 2003, with permission from American Chemical Society.)...

Figure 9.8. The GC/ITMS analysis of THPI (0.13mg/kg) and captan (0.76mg/kg) in a grape sample using the analytical conditions described in Table 9.10. (Reproduced from Journal of Agricultural and Food Chemistry, 2003,51, p. 6763, Angioni et al., with permission of American Chemical Society.)...

Shelver, W.L., and Smith, DJ. (2003) Determination of ractopamine in cattle and sheep urine samples using an optical biosensor analysis comparative study with HPLC and ELISA. Journal of Agriculture and Food Chemistry, 51, 3715 3721. 

Driedger, D.R., and Spoms, P. (2001) Immunoaffinity sample purification and MALDI TOF MS analysis of a solanine and a chaconine in serum. Journal of Agricultural and Food Chemistry, 49, 543 548. 

Modem extraction techniques food and agricultural samples / Charlotta Turner, editor sponsored by the ACS Division of Agricultural and Food Chemistry. 

This book is based on the symposium entitled Modem Extraction Techniques for Food and Agricultural Samples, which was arranged by the Division of Agricultural and Food Chemistry during the American Chemical Society s 227th national meeting in Anaheim, California, held March 28-April 2,2004. 

Wastes and by-products from agricultural and food processing contain many potential useful bioactive compounds. It is important to determine the presence and solubility of these compounds in SC-CO2 before designing an industrial extraction plant. The objective is often to use the extracts for food/feed, pharmaceutical or cosmetic purposes. Sample preparation is particularly difficult because of the heterogeneity of the possible discarded materials in terms of chemical, physical and (micro)biological composition. 

Figure 10.6. Fluorescence spectra on 430 nm excitation of Idra wheal flour added with variable amounts of RBF from top to bottom, dashed line, 25 f

Breton, C., Claux, D., Metton, I., Skorski, G., and BerviUe, A. Comparative study of methods for DNA preparation from olive oil samples to identify cultivar SSR alleles in commercial oil samples Possible forensic applications. Journal of Agriculture and Food Chemistry, 52, 531-537. 2004. 

Figure 3.15 Headspace gas chromatographic analysis of a volatile hydrocarbon mixture representing c. 0.3 ng of each component. Chromatographic conditions 30 m x 0.32 mm fused silica column coated with DB-5, 40°C (11 min), then 20°Cmin to 150°C, Ni electron-capture detection. Sample thermostatted at 60°C. Reproduced from Uhler, A. D. and Miller, L. J., Multiple headspace extraction gas chromatography for the determination of volatile hydrocarbon compounds in butter, Journal of Agricultural and Food Chemistry, 36, 772-5, 1988.

Wang, G. et al. Accelerated solvent extraction and gas chromatography/mass spectrometry for determination of polycyclic aromatic hydrocarbons in smoked food samples. Journal of Agricultural and Food Chemistry, 47,1062,1999. 

FIGURE 3.13 Variation of log(l /Roo) vs. the fraction of wheat in a sample composed of rape seed and wheat. The markers show the experimental values of log(l/f oo) vs. the fraction of wheat in the mixture while the lines show the shape predicted by the representative layer theory. The top curve is for wheat and rape seed of the same particle size. In the bottom curve, the wheat particles are twice the size of the particles of rape seed. (Reproduced from D. J. Dahm and K. D. Dahm, Near-Infrared Technology in the Agriculture and Food Industries, 2nd edn. (R Williams and K. Norris, eds.), St. Paul, MN, pp. 1-17 (2001) by permission of American Association of Cereal Chemists, Inc. Copyright 2001.)... 

---