Tuna fish, analysis

Quevauviller Ph, and Maier EA (1999) Interlaboratory studies and certified reference materials for environmental analysis - the BCR approach. Elsevier, Amsterdam Quevauviller Ph, Drabaek I, Muntau H, Biahchi M, Bortoli A, and Griepink B (1996a) Certified reference materials (CRMs 463 and 464) for the quafity control of total and methyl mercury determination in tuna fish. Trends Anal Chem 15 160-167. 

A rapid and simple MW-assisted digestion method with alkaline solution (TMAH or methanolic KOH solution) was developed for speciation analysis of inorganic Hg and methyl-Hg in biological tissues [41]. Extracts with quantitative recoveries of Hg species after the alkaline dissolution of the sample were directly analyzed by an automated on-line hyphenated system incorporating aqueous HG, cryogenic trapping, GC, and detection by A AS. The proposed method was validated by the analysis of biological CRMs (CRM 463, DORM-1, TORT-1) and one BCR sample from an interlaboratory study (Tuna Fish 2). 

A simple and rapid procedure was developed for the simultaneous determination of methyl-Hg and Hg(II) in Psh CRMs [43], The procedure was based on a rapid MW-assisted solubilization of biomaterial with TMAH, simultaneous quantitative ethylation-extraction of the Hg species into hexane, Bash isothermal separation using minicolumns, and Pnal detection by MIP-AES. The method was validated for speciation analysis for HG using the BCR 463 and 464 Tuna Fish CRMs. 

A simple and rapid MW-assisted alkaline digestion procedure was developed in combination with high-performance liquid chromatography (HPLC)DUV postcolumn oxidationDCVDAFS detection for methyl-Hg determination in biological tissues [45]. The accuracy of the method was evaluated by the analysis of the BCR 463 Tuna Fish CRM. 

Accuracy and Analytical Quality Control Aspects The analysis of certified reference materials (CRMs) following the same analytical procedures was performed for assessment of the accuracy of the procedure and for quality control (QC). Yet, the available CRMs are mostly freeze-dried, not fresh or deep-frozen. In Table 22.3 an overview of CRMs in a seafood matrix with respect to organic Hg is given. It is certainly beneficial that more and more CRMs are becoming commercially available. Recently, a new CRM for trace elements in a matrix of lyophilized tuna fish (IMEP-20) has been produced [44]. Apart from total Hg (4.32 mg kg-1 dry mass) and Me-Hg (4.24 mg kg-1 dry mass), this material is also certified for other elements such as As, Pb, and Se. 

AAS and AFS are used to detect metals in environmental samples in both trace and major concentrations. Analysis of metals like lead, mercury and cadmium in various samples such as tuna fish soils , mushrooms and shellfish is very common. AAS has been reported for the determination of drugs such as bromhexine, flunarizine and ranitidine hydrochlorides in pharmaceutical formulations down to concentrations of <2pg/mL . AAS has been used to analyse cadmium and lead in blood samples . The concentration ranges were 0.20-1.73 ppb and 12.0-65.7 ppb for cadmium and lead respectively. The techniques of AAS and AFS are also very popular in the analysis of herbal medicines - . ... 

TLC ANALYSIS OF AMINES IN COMMERCIAL (NONDECOMPOSED) AND DECOMPOSED CANNED TUNA FISH ... 

The stability of arsenobetaine and DMA in tuna fish was tested over a period of 9 months at — 20°C, +20 °C and +40 °C by performing one determination on each of live bottles stored at different temperatures after 1, 3, 6 and 9 months. The reproducibility of the analytical method (same as the one used in the homogeneity study) was verified by determining a portion of raw extract (prepared at the beginning of the study and stored at — 20°C) at each occasion of analysis. In addition, the stability of the material and of the raw extract was also verified by qualitative control of the chromatograms no unexpected peaks containing arsenic were detected. The results showed that no instability could be demonstrated for both arsenobetaine and DMA at +20 °C and+40 C [134]. 

Figure 10.260 Analysis of biogenic amines in a tuna fish sample with suppressed conductivity detection. Separator column lonPac CS17 eluent MSA (EG) gradient 3-18mmol/L linearly in 10 min, isocratically at 18mmol/L for 4 min, and then linearly to 25 mmol/L in 4.5 min flow rate 1 mlVmin detection ...

Several applications have been reported for food analysis, including the determination of ethanol in wines (Sramkova et al., 2014), trace inorganic mercury in mussel and tuna fish tissue (Mitani et al., 2014), phthalates (Clavijo et al., 2014), inorganic mercury (Mitani et al., 2014) in drinking waters, and the illegal food additive rhodamine B (Maya et al., 2012a). 

The certification procedure for seven trace metals (Ba, Ca, Li, Mg, Mn, Na and Sr) in the certified reference material FEBS-1 (National Research Council Canada, Institute for National Measurement Standards, Ottawa, Canada) based on fish otolith matrix by isotope dilution - ICP-MS in comparison to ICP optical emission spectrometry and X-ray fluorescence analysis, is described by Sturgeon et al4X The isotope dilution technique is also employed for species analysis in biological systems,46 e.g., for the determination of mercury species in tuna material,54 or in aquatic systems using cold vapour ICP-MS.55... 

Moret et al. (67,68) studied all the parameters that influence amine recovery under conditions where a liquid-liquid purification step with an organic solvent follows the acid extraction, prior to derivatization with DBS and RP-HPLC analysis. The optimized methods of sample preparation for different foods, including cheese, meat, and fish, are given. The same research group (69) optimized the extraction conditions for Phe, Put, Cad, His, Tyr, Spe, and Spd. Food samples were first mixed with TCA and centrifuged and then basified and extracted with BuOH/CHCl3 (1 1). The BAs were then derivatized with DNS and separated on a Spherisorb 3S TG column with an ACN-H20 gradient. The method was applied to samples of tuna, salmon, and salami. 

SSCP analysis has been found useful for the authentication of various types of seafood. As shown in Table 5.2, a considerable number of fish species, shrimps, and mollusks could be identified by SSCP of mitochondrial or nuclear genes. As SSCP gives very good results for short DNA segments, species identification of products containing severely degraded DNA (e.g., canned tuna) may be easier to achieve by SSCP than by RFLP (Rehbein et al., 1999). In a study of fish meal authentication, SSCP and RFLP-SSCP allowed differentiation between meals produced from a number of fish species, including two closely related sand eel species (Rehbein, 2002). 

Weder JKP, Rehbein H, Kaiser K-P (2001). On the specificity of tuna-directed primers in PCR-SSCP analysis of fish and meat. Eur. Food Res. Technol, 213 139-144. 

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