Search

An approach was developed for the verification of method performance of the AOAC 2005.06 LC-fluorescence detector (FLD) method for determination of paralytic shellfish poisoning (PSP) toxins in bivalve shellfish. This was developed following advice published by the Analytical Laboratory Accreditation Criteria Committee and applied to shellfish species that had not been previously subjected to a full single-laboratory validation scheme. The refined approach was developed following the need to assess performance in a number of shellfish species infrequently monitored through the UK statutory monitoring program, while reducing the impact and cost of the studies, most notably in terms of the use of valuable reference standards. The species assessed were manila clams (Ruditapes philippinarum), European otter clams (Lutraria lutraria), grooved carpet shell clams (R. decussatus), surf clams (Spisula solida), and king scallops (Pecten maximus) presented as adductor only or adductor plus roe. The method was assessed for sensitivity in terms of LOD and LOQ, toxin recovery, and method precision in each species. It incorporated the PSP toxins deemed toxic and/or prevalent in UK samples and commercially available as certified reference standards. The toxins studied included GTX1-5, dcSTX, STX, C1&2, and NEO. The toxins dcGTX2&3 were included for surf clams due to the prevalence of these toxins in this species as a result of toxin decarbamoylation. Method performance targets were met for each of the characteristics investigated. Consequently, the method was deemed fit for purpose for the screening and quantification of these clam and scallop species for PSP toxins by AOAC Method 2005.06 LC-FLD.

AOAC Official Method 2005.06 LC-fluorescence detection (FLD) method is an official alternative to the mouse bioassay for the determination of paralytic shellfish poisoning (PSP) toxins in bivalve shellfish. To validate the method for species of relevance to the UK official control monitoring program, the method performance characteristics were tested for whole king and queen scallops. Validation showed that, while the performance was generally acceptable for the quantitation of non-N-hydroxylated toxins, poor toxin recovery and sensitivity was evident for the analysis of N-hydroxylated toxins following periodate oxidation. These effects occurred in a range of scallop samples with variable temporal and spatial sources. The effects were also noted in other laboratories following a small interlaboratory study. As a result, the method was refined to improve the recovery and sensitivity of analysis following the periodate oxidation step in the PSP method for scallops. Performance improved through alterations to the preparation of the periodate oxidant, use of higher volumes for C18 cleanup, and injection volumes in combination with the use of a king scallop matrix modifier for oxidation of N-hydroxylated toxin calibration standards. A single-laboratory validation of the refined method showed that the selectivity, linearity, sensitivity, recovery, and precision were acceptable and similar to values reported previously for AOAC Official Method 2005.06 in other bivalve species. Results showed the method to be rugged for all parameters investigated, including small changes to the composition of the new periodate reagent utilized in the refined method. The refined scallops LC method was subsequently compared with the European reference method. PSP-positive scallops showed an excellent agreement between the methods for queen and Atlantic scallops, with a small level of positive bias in the LC results for whole king scallops. These differences were related solely to the use of the highest toxicity equivalence factors for toxin epimeric pairs, with gonyautoxin (GTX)1,4 and GTX2,3 in particular present at high concentrations in the king scallops. Overall, the refined LC-FLD method improved the performance characteristics of AOAC Official Method 2005.06 for the determination of PSP toxins in whole king and queen scallops, and showed a good overall agreement between the official methodologies. It is, therefore, recommended as a more appropriate option for the routine monitoring of PSP toxins in these species.

To develop a new drug delivery system, antibacterial 50-900 nm nanoparticles of shell and internal organs from scallops collected off Huksan-Island, Korea, were prepared by dry grind technology respectively. The diameters, identities, and conformations of the scallop shell and internal organ particles were determined with a particle-size analyzer and by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. The antibacterial properties of the nanoparticles from scallop shell were investigated in the absence and the presence of scallop-shell extract. Bacterial growth was reduced with the supernatant of the nanoparticle scallop-shell extract. Also, the nanoparticles from scallop shell were much more effective as a skin softener than was powder. These facts provide us with guidelines for the study of the size-dependent properties of functional materials as well as for further applications to drug delivery systems (DDSs) and cosmetic raw materials.

The edible thorny oyster, Spondylus varius (Mizuiri-shoujou), was found to suppress the carbon tetrachloride-induced increase in serum aspartate and alanine aminotransferase activities in mice. Significant suppressive effects on these enzyme activities were found in the fraction eluted with 75% ethanol from polystyrene gel in a dose-dependent manner. These results suggest that S. varius exerts a protective effect against liver injury.

The lipolytic effect of powdered scallop shells was estimated in vitro and in vivo. The scallop shells consisted of 98% calcium carbonate and 2% organic compounds, the extracted organic components promoted lipolysis in 3T3-L1 adipocyte cells. Male Wistar rats were fed on an experimental diet containing either the scallop shell powder or calcium carbonate (control) for 28 d. Feeding the scallop shell powder resulted in a decrease in body weight and in the weight of white adipose tissue. While the organ weights of the liver, kidney, testis, pancreas, and spleen, and of the brown adipose tissue relative to the body weight were no different between the scallop shell powder diet and control diet, the white adipose tissue weight relative to the body weight significantly decreased in the rats fed on the scallop shell powder. The glycerol concentration in the serum increased in the rats fed on the scallop shell powder, suggesting that this promoted lipolysis in the adipose tissue. These results show that the organic components in the scallop shells induced the decrease in weight of the adipose tissue due to the promotion of lipolysis.

Objective: To report a case of occupational asthma and urticaria due to the queen scallop (Chlamys opercularis) and king scallop (Pectin maximus)., Background: A 40-year-old female worked in a shellfish-processing plant, handling king and queen scallops for 5 years. At the time of investigation, she described a 2-year history of work-related respiratory symptoms., Methods: Serial peak expiratory flow rate readings were recorded and an OASYS study completed. A workplace visit was undertaken and specific immunoglobulin (IgE) radioallergosorbent (RAST) testing of scallop extracts was performed., Results: The OASYS study was consistent with occupational asthma. RAST testing demonstrated evidence of specific sensitization (IgE) to queen and king scallop. There was also some cross-reactivity observed with other shellfish (prawns and crabs)., Conclusion: Workers exposed to aerosols from scallop species are at risk of occupational asthma and require effective respiratory health surveillance.