Lobster Hepatopancreas Research Articles

Experimental designoptimisation and validation by accuracy profile of a novel method for Hg speciation analysis by HPLC-ICP-MS and application to Total Diet Studies.

This study addresses the development and validation of an analytical method for speciation analysis of mercury (inorganic/Hg2+ and methylmercury/CH3Hg+) in fishery products. The Hg species are separated by reversed-phase (RP) high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The effective separation of Hg2+ and CH3Hg+ was achieved in <8min using a peptide mapping RP column and a mobile phase containing 2-mercaptoethanol at 0.25% (v/v) and methanol at 1%(v/v). The optimization was carried out using an experimental design through response surface methodology (RSM) with central composite design (CCD), addressing both the HPLC separation and the sample extraction. The method validation was carried out based on the accuracy profile approach. For this purpose, six series of measurements were carried out in duplicate over a time span of 2 months. The limits of quantification (LOQ) were 2.5µg/kg (wet weight, ww) for CH3Hg+ and 1.2µg/kg (ww) for Hg2+. The intermediate reproducibility in terms of coefficient of variation (CVR) was <6%. The bias (%) obtained for the analysis of four certified reference materials (CRMs), namely TORT-3 (lobster hepatopancreas), SRM 1566-b (oyster tissue), SQID-1 (cuttlefish) and NMIJCRM7402-a (cod fish tissue) was <7%. This demonstrates the method robustness and suitability for routine speciation analysis of CH3Hg+ and Hg2+ in fishery products. The method is intended to be applied for the analysis of the panel of fishery products and fish-based foods in the framework of the (ongoing) third French Total Diet Study.

Nickel−manganese−cobalt tetragonal spinel ternary oxide nanocomposite as an effective adsorbent for dispersive solid phase micro-extraction of cadmium in food and water samples

Nickel−manganese−cobalt tetragonal spinel ternary oxide nanocomposite (NMC-TSO) was synthesized. It was utilized as an efficient sorbent for the dispersive solid phase microextraction (D-SPμE) without vortexing of cadmium. The analysis of the cadmium was carried out by FAAS. The effective analytical parameters including pH (6) contact times (no vortexing), sample volume (70 mL), eluent volume (3 mL of 2 mol L−1 HCl), linear dynamic ranges (1.07–85.7 μg L−1), and re-useability (33) on the D-SPμE efficiency were investigated. The PF, RSD% and LOD of the D-SPμE for cadmium were 23.3, ≤ 2.8% and 0.49 μg L−1, respectively. The tolerable concentrations of Ca2+, Mg2+, K+ and Na+ on Cd(II) were 50,000 mg L−1, 50,000 mg L−1, 25,000 mg L−1 and 7500 mg L−1, respectively. The method was accurated by analysis of food and water certificate reference materials (NW-TMDA-54.6 Lake water, SPS-WW1 121 Batch wastewater, 1573a Tomato Leaves and TORT-3 Lobster Hepatopancreas) and - recovery experiments. The D-SPμE-FAAS method was applied for the cadmium determination in dam water, wastewater, river water, well water, sea water, tea, cacao, nut, bitter chocolate, rice, leek, cinnamon and parsley.

Development and initial evaluation of a combustion-based sample introduction system for direct isotopic analysis of mercury in solid samples via multi-collector ICP-mass spectrometry

High-precision isotopic analysis of mercury (Hg) using multi-collector ICP-mass spectrometry (MC-ICP-MS) is a powerful method for obtaining insight into the sources, pathways and sinks of this toxic metal. Modification of a commercially available mercury analyzer (Teledyne Leeman Labs, Hydra IIc – originally designed for quantification of Hg through sample combustion, collection of the Hg vapor on a gold amalgamator, subsequent controlled release of Hg and detection using cold vapor atomic absorption spectrometry CVAAS) enabled the system to be used for the direct high-precision Hg isotopic analysis of solid samples using MC-ICP-MS – i.e., without previous sample digestion and subsequent dilution. The changes made to the mercury analyzer did not compromise its (simultaneous) use for Hg quantification via CVAAS. The Hg vapor was mixed with a Tl-containing aerosol produced via pneumatic nebulization, creating wet plasma conditions, and enabling the use of Tl as an internal standard for correction of instrumental mass discrimination. Accurate and precise (0.10 ‰ 2SD, δ202Hg, n = 5) results were obtained for an in-house standard solution of Hg (20 ng Hg sample intake). Initial validation relied on the successful analysis of two solid certified reference materials of biological origin (BCR CRM 464 Tuna fish and NRC-CNRC TORT-3 Lobster hepatopancreas). It was shown that instrumental mass discrimination can be adequately corrected for by relying on the use of an aqueous Hg standard solution (NIST SRM 3133), without the need of matrix-matching. The novel setup developed thus allows for direct high-precision isotopic analysis of Hg in solid samples, thus enhancing the sample throughput. It is also suited for samples for which low amounts are available only and/or that are characterized by low Hg concentrations.

Trace elements in bean-to-bar chocolates from Brazil and Ecuador

BackgroundThe high quality and unique flavor and aroma of bean-to-bar chocolates have resulted in an increase in the consumption of these products. Nevertheless, cocoa beans may present inorganic contaminants from environmental and anthropogenic sources which can contribute to contamination of the chocolates, despite the fewer processing steps and few ingredients used in bean-to-bar manufacturing process compared to the industrial one. Therefore, this study aimed to evaluate the content of trace elements (As, Cd, Co, Cu, Hg, Pb, Se) in bean-to-bar chocolates and traceable cocoa beans from Brazil and Ecuador. MethodsBean-to-bar chocolate samples were acquired in Brazil (n=65) and Ecuador (n=10), considering the main products available: white, milk, semisweet and dark chocolate. Cocoa samples from dedicated farms (n=23) were analyzed for trace elements and inorganic contaminants regulated by Brazil and European agencies. Samples were mineralized using acid digestion (nitric acid and hydrogen peroxide) in a closed microwave-assisted system. Quantification of trace elements was performed using Inductively coupled plasma mass spectroscopy (ICP-MS) and Inductively coupled plasma optical emission spectroscopy (ICP OES) in optimized conditions. The analytical control was performed with certified reference materials (ERM BD512 - Dark Chocolate, Tort-2 and Tort-3 - Lobster Hepatopancreas and SRM 1547 - Peach leaves) and recoveries ranged between 84% and 105% for all elements. ResultsThe trace element levels in the bean-to-bar chocolates were (mg/kg): As (<0.022–0.023), Cd (<0.002–0.74), Cu (0.11–21.2), Co (<0.003–1.88), Hg (<0.010-<0.010), Pb (<0.007–0.22), and Se (<0.029–0.35). The exposure assessment from inorganic contaminants in chocolates revealed up to 93% of provisional tolerable monthly intake (PTMI) for Cd and 123% of tolerable upper intake level (UL) for Co for children. Inorganic contaminants were also analyzed in cocoa beans from dedicated farms and Cd and Pb levels were found above the thresholds established by Brazil health agency. ConclusionThe results observed for both bean-to-bar chocolates and raw materials (cocoa beans from dedicated farms) indicated a need for monitoring these trace elements.

American lobster (Homarus americanus) hepatopancreas transcriptome reveals the significance of chitin-related genes during impoundment shell disease

American lobsters ( Homarus americanus) stored in open tidal pounds can develop impoundment shell disease (ISD), resulting in decreased marketability of the lobsters on the live market. Little is known about ISD or the immunological responses of lobsters exhibiting this disease. The objective of this project was to identify genes from H. americanus hepatopancreas that are differentially expressed in response to ISD. Lobsters were separated into asymptomatic, moderately symptomatic, and severely symptomatic groups, which represent animals with 0%, 5%–20%, and &gt;20% lesion coverage of the carapace, respectively. RNA-seq analysis found that 134 genes were differentially expressed between groups (false discovery rate (FDR) &lt; 0.05). Most, 80, of these genes were found exclusively in the comparison between moderately symptomatic and asymptomatic groups. All animals clustered in their proposed groups based on the expression of the differently expressed genes (DEGs), and the asymptomatic group clustered as an out-group. The expression of most DEGs was higher in the asymptomatic group than the others, which could be related to a stronger response against the disease or differences in individual resistance against ISD development. Among these genes, we highlight eight chitin-related genes, one α-2-macroglobulin-like gene, one acute phase serum amyloid A gene, one pseudohaemocyanin gene, and one trypsin-1-like gene.

Comparison between Microwave Digestion and Conventional Open Digestion Method for Heavy Metals determination

In the present study a comparison between microwave assisted digestion and conventional wet acid open digestion system for dissolution of bivalve tissue samples was carried out. Sample matrix decomposition was done by using a mixture of concentrated nitric acid and hydrogen peroxide. The determination of trace elements (Zn, Co, Cu, Cd and Pb) in commercially popular bivalve species from two important fish landing centers in Mumbai was used for this purpose. The recovery of heavy metals after analysis was done using certified reference material TORT 2- Lobster hepatopancreas for both the digestion methods. The results of the present study indicate that microwave digestion system for heavy metal analysis is the preferred method for rapid and good quality results. It provides better recovery and precision for heavy metal analysis. The sample preparation step is much easier by microwave digestion system compared to conventional open digestion methods for heavy metal analysis. It is particularly ideal for trace metals like lead and cadmium as they are generally present in very small concentration in biological samples. In the current study microwave digestion proved to be better method than conventional open digestion method with rapid sample digestion process and least sample contamination problem.

Health Status of Spiny Lobster Panulirus homarus with Sub-Mersible Net Cage System in the Different Depths at Kepulauan Seribu, DKI Jakarta

ABSTRACT&#x0D; Cultivation of Panulirus homarus lobster is now carried out with sub-mersible net cage system at a certain depth in order to obtain optimal temperature, light and water pressure. The purpose of this study was to evaluate the health status of the sand lobster P. homarus which was kept in sub-mersible net cage system measuring 250 cm × 272 cm × 135 cm with a depth of 6 m and 8 m in the waters of Semak Daun Island, Seribu Islands, DKI Jakarta. The average size of lobster seeds used was 93.23 ± 0.99 g/head with a density of 4 lobsters/m2. Lobsters were fed trash fish, molluscs and crustaceans, with a frequency of twice a day at 07.00 WIB 30% and 17.00 WIB 70% of the lobster biomass weight. This study used a completely randomized design with the two depth treatments mentioned above and three replications. Observations of total haemocyte count, differential haemocyte count, phenoloxidase activity, respiratory burst phagocytic activity and histology of lobster hepatopancreas were performed twice every 14 days. Based on the above observations, the depth does not affect the immune response, there is no visible damage to the cells and tissues of the lobster hepatopancreas.&#x0D; Keywords: haemolymph, histology, lobster cultivation, sea, sub-mersible net cage system

Sensitive determination of Ag, Bi, Cd, Hg, Pb, Tl, and Zn by inductively coupled plasma optical emission spectrometry combined with the microplasma-assisted vapor generation

A technique of vapor generation assisted by a microplasma was used for sample introduction into inductively coupled plasma optical emission spectrometry (ICP OES). Replacing a pneumatic nebulizer with a novel microplasma device improved the sensitivities of analytical signals for Ag, Bi, Cd, Pb, Tl, and Zn (by 2–13 times), as well as a concomitant reduction in their detection limits (DLs). Moreover, an outstanding improvement (30-fold) was achieved for Hg. The factors contributing to the boosted signal intensities were higher analyte fluxes and less water vapor produced by the microplasma system. The DLs of Ag, Bi, Cd, Hg, Pb, Tl, and Zn in microplasma-ICP OES were 0.4, 4, 0.06, 0.2, 2, 5, and 0.2 μg L−1, respectively, and the measurement precision was within the range of 0.7–2.4% (it was significantly improved as compared to that achievable with pneumatic nebulization). The proposed microplasma-assisted vapor generation eliminates the use of toxic reductants, e.g., sodium tetrahydridoborate, and it is characterized by higher resistance to matrix effects from transition metal ions (as compared to chemical vapor generation (CVG) and photochemical vapor generation (PVG)). To validate the trueness of the SAGD-ICP OES method, certified reference materials of lobster hepatopancreas (TORT-2), cormorant tissue (MODAS-4) as well as spiked tap water and seawater samples were analyzed to determine levels Cd and Hg. The standard additions method was used for calibration in both cases. Recoveries of the analytes in the case of the analysis of TORT-2 and MODAS-4 samples as well as the spiked tap water and seawater was within the range of 98–113%, which indicated that the developed sample introduction system can be successfully used for very sensitive determinations of selected hazardous elements in environmental samples.

Determination of Ag, Bi, Cd, Hg, Pb, Tl, and Zn by inductively coupled plasma mass spectrometry combined with vapor generation assisted by solution anode glow discharge – A preliminary study

A new technique of vapor generation assisted by a microplasma was proposed for an inductively coupled plasma mass spectrometry (ICP MS). It was found that, by replacing a traditional pneumatic nebulizer with a microplasma (solution anode glow discharge, SAGD), analytical signals of Ag, Bi, Cd, Hg, Pb, Tl, and Zn were improved 8, 4, 13, 13, 9, 10, and 7 times, respectively. The main factor contributing to boosted analytical signal intensities was the higher analyte flux produced by the novel microplasma system. The measurement precision in SAGD-ICP MS was comparable to that achievable for ICP MS (with pneumatic nebulization), and it did not exceed 2%. The detection limits of Ag, Bi, Cd, Hg, Pb, Tl, and Zn in SAGD-ICP MS were 5, 2, 6, 5, 4, 10, and 20 ng L−1, respectively. The analytical performance of this method may be further improved if the observed memory effects could be minimized. To validate the trueness of the novel method, certified reference materials of lobster hepatopancreas (TORT-2), cormorant tissue (MODAS-4), and wastewater (ERM CA-713) were analyzed to determine traces of Cd, Hg, and Pb. Recoveries of certified values for these analytes were ranged from 91 to 111%, which indicated that the studied microplasma system in combination with ICP MS can be successfully used for very sensitive determinations of selected hazardous elements in environmental samples.

Field Validation of the Southern Rock Lobster Paralytic Shellfish Toxin Monitoring Program in Tasmania, Australia.

Paralytic shellfish toxins (PST) are found in the hepatopancreas of Southern Rock Lobster Jasus edwardsii from the east coast of Tasmania in association with blooms of the toxic dinoflagellate Alexandrium catenella. Tasmania’s rock lobster fishery is one of the state’s most important wild capture fisheries, supporting a significant commercial industry (AUD 97M) and recreational fishing sector. A comprehensive 8 years of field data collected across multiple sites has allowed continued improvements to the risk management program protecting public health and market access for the Tasmanian lobster fishery. High variability was seen in toxin levels between individuals, sites, months, and years. The highest risk sites were those on the central east coast, with July to January identified as the most at-risk months. Relatively high uptake rates were observed (exponential rate of 2% per day), similar to filter-feeding mussels, and meant that lobster accumulated toxins quickly. Similarly, lobsters were relatively fast detoxifiers, losing up to 3% PST per day, following bloom demise. Mussel sentinel lines were effective in indicating a risk of elevated PST in lobster hepatopancreas, with annual baseline monitoring costing approximately 0.06% of the industry value. In addition, it was determined that if the mean hepatopancreas PST levels in five individual lobsters from a site were <0.22 mg STX equiv. kg−1, there is a 97.5% probability that any lobster from that site would be below the bivalve maximum level of 0.8 mg STX equiv. kg−1. The combination of using a sentinel species to identify risk areas and sampling five individual lobsters at a particular site, provides a cost-effective strategy for managing PST risk in the Tasmanian commercial lobster fishery.

Robust Potassium Isotopic Analysis of Geological and Biological Samples via Multicollector ICP-Mass Spectrometry Using the "Extra-High Resolution Mode".

Potassium isotopic analysis is arousing increasing interest, not only in geochemistry, but also in biomedicine. However, real-life applications are still hindered by the lack of robustness of the methods used. In this work, a novel and robust method for high-precision K isotopic analysis of geological and biological samples was developed, based on the use of a multicollector ICP-mass spectrometer providing a mass resolving power of 15,000 (extra-high resolution mode, XHR). After evaluation of different measurement conditions, i.e., hot vs cold plasma conditions, standard-type vs jet-type sampling cone, and high resolution (HR) vs XHR, a combination of hot plasma conditions, use of the high-transmission jet-type sampling cone, and the XHR mode allowed for high-precision and interference-free K isotopic analysis. Potassium signal monitoring was performed in the ArH+ interference-free 0.006-0.007 amu wide peak shoulder using the XHR mode. The within-run, short-term external, and long-term external precisions for the δ41K value were 0.02‰ (2se, N = 50), 0.03‰ (2SD, N = 7), and 0.06‰ (2SD, N = 163), respectively. A two-stage chromatographic procedure was developed for the isolation of K from both geological and biological samples, and potential matrix effects affecting the K isotope ratio were systematically evaluated. The method was first applied to geological reference materials (RMs) for validation purposes, and the K isotope ratio results were in good agreement with those previously reported. Subsequently, a series of biological RMs, including serum, whole blood, cerebrospinal fluid, bovine muscle, and lobster hepatopancreas, were characterized for their K isotopic composition.

Methanol-Enhanced Liquid Electrode Discharge Microplasma-Induced Vapor Generation of Hg, Cd, and Zn: The Possible Mechanism and Its Application.

Despite increased interest in microplasma-induced vapor generation (μPIVG) over the past several years, applications in real sample analyses remain limited due to their relatively low vapor generation efficiency and ambiguous mechanism. In this work, a novel method using methanol for significantly enhancing the liquid electrode discharge μPIVG efficiency was developed for the simultaneous and sensitive determination of Hg, Cd, and Zn by atomic fluorescence spectrometry (AFS). It is worth noting that the possible enhancement mechanism was investigated via the characterizations of volatile products by AFS, microplasma optical emission spectrometry, online gas chromatography, and gas chromatography-mass spectrometry, which involved the reductive species such as electrons, hydrogen radicals (·H), methyl radicals (·CH3), and other intermediates in the argon plasma adding methanol. Under the optimized conditions, the limits of detection of 0.007, 0.05, and 0.5 μg L-1 were obtained for Hg, Cd, and Zn, respectively, with relative standard deviations of 3.1, 3.7, and 5.2% for these elements, respectively. Vapor generation efficiencies of 90, 83, and 55% were achieved for Hg, Cd, and Zn, respectively, and improved 2.7-, 4.8-, and 7.9-fold, respectively, compared to those obtained in the absence of methanol. The accuracy and practicability of the proposed method were validated by the determination of Hg, Cd, and Zn in a certified reference material (CRM, Lobster hepatopancreas, TORT-3) and crayfish samples collected from three different provinces of China.

Speciation analysis of organoarsenic species in marine samples: method optimization using fractional factorial design and method validation

Organoarsenic species in marine matrices have been studied for many years but knowledge gaps still exist. Most literature focuses on monitoring of arsenic (As) species using previously published methods based on anion- and cation-exchange high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). These studies are often limited to few As species and/or only specific method performance characteristics are described. Most marine certified reference materials (CRMs) are only certified for arsenobetaine (AB) and dimethylarsinate (DMA), making it difficult to evaluate the accuracy of analytical methods for other organoarsenic species. To address these gaps, the main objective of this work was to develop and validate a method for speciation analysis of a broad range of organoarsenic species in marine matrices. Optimum extraction conditions were identified through a 27–3 fractional factorial design using blue mussel as test sample. The effects of sample weight, type and volume of extraction solution, addition of H2O2 to the extraction solution, extraction time and temperature, and use of ultrasonication were investigated. The highest As recoveries were obtained by using 0.2 g as sample weight, 5 mL of aqueous methanol (MeOH:H2O, 50% v/v) as extractant, extraction carried out at 90 °C for 30 min, and without ultrasonication. Anion- and cation-exchange HPLC-ICP-MS settings were subsequently optimized. The method detected a total of 33 known and unknown As species within a run time of 23 and 20 min for cation-exchange and anion-exchange, respectively. A single-laboratory validation was conducted using several marine CRMs: BCR 627 (tuna fish tissue), ERM-CE278k (mussel tissue), DORM-4 (fish protein), DOLT-5 (dogfish liver), SQID-1 (cuttlefish), TORT-3 (lobster hepatopancreas), and CRM 7405-b (hijiki seaweed). Method performance characteristics were evaluated based on selectivity, limits of detection and quantification, linearity, trueness, precision, and measurement uncertainty. This work proposes an extraction procedure which allowed satisfactory quantification of As species with low solvent and energy consumption, supporting “Green Chemistry” principles. The study also presents a new set of As speciation data, including methylated arsenic species and arsenosugars, in recently issued marine CRMs, which will be valuable for future speciation studies on As. This work is the first to report a total of 33 different As species in marine CRMs.Graphical abstract

Lobster Supply Chains Are Not at Risk from Paralytic Shellfish Toxin Accumulation during Wet Storage.

Lobster species can accumulate paralytic shellfish toxins (PST) in their hepatopancreas following the consumption of toxic prey. The Southern Rock Lobster (SRL), Jasus edwardsii, industry in Tasmania, Australia, and New Zealand, collectively valued at AUD 365 M, actively manages PST risk based on toxin monitoring of lobsters in coastal waters. The SRL supply chain predominantly provides live lobsters, which includes wet holding in fishing vessels, sea-cages, or processing facilities for periods of up to several months. Survival, quality, and safety of this largely exported high-value product is a major consideration for the industry. In a controlled experiment, SRL were exposed to highly toxic cultures of Alexandrium catenella at field relevant concentrations (2 × 105 cells L−1) in an experimental aquaculture facility over a period of 21 days. While significant PST accumulation in the lobster hepatopancreas has been reported in parallel experiments feeding lobsters with toxic mussels, no PST toxin accumulated in this experiment from exposure to toxic algal cells, and no negative impact on lobster health was observed as assessed via a wide range of behavioural, immunological, and physiological measures. We conclude that there is no risk of PST accumulation, nor risk to survival or quality at the point of consumption through exposure to toxic algal cells.

Inter-comparison of stable iron, copper and zinc isotopic compositions in six reference materials of biological origin

There is a lack of certified reference materials with an organic matrix for which metal isotope ratios have been certified. Here, we have determined the iron, copper and zinc stable isotopic compositions for six reference materials of biological origin with diverse matrices, i.e. BCR-380R (whole milk), BCR-383 (beans), ERM-CE464 (tuna fish), SRM-1577c (bovine liver), DORM-4 (fish protein) and TORT-3 (lobster hepatopancreas) in three different labs. The concentrations for six major and sixteen trace elements, spanning almost four orders of magnitude, were also measured and the results obtained show an excellent agreement with certified values, demonstrating that the dissolution step was quantitative for all the standards. By taking literature data into account, 39 possible pair-wise comparisons of mean iron, copper and zinc isotopic values (δ values) could be made. Results of Tukey multiple comparisons of means yielded 11 significantly different pairs. Most of these differences are of the same order of magnitude as the estimated mean expanded uncertainties (U, k = 2) (±0.10‰, ±0.05‰, and ±0.05‰ for the δ56Fe, δ65Cu and δ66Zn values, respectively). The present inter-comparison study finally proposes nineteen new preferred values for the Cu, Zn and Fe isotopic compositions of six reference materials of biological origin.

ITRAQ-Based Proteomic Profile Analysis of the Hepatopancreas of Caribbean Spiny Lobsters Infected With Panulirus argus Virus 1: Metabolic and Physiological Implications.

The Caribbean spiny lobster Panulirus argus (Latreille, 1084) sustains economically valuable fisheries throughout the wider Caribbean region. This species is currently affected by the pathogenic virus Panulirus argus Virus 1 (PaV1) that causes a systemic and chronic-degenerative infection in juvenile spiny lobsters P. argus. To date, there is no available information regarding the host alterations induced by this pathogen at the molecular level. In the present study, comparative proteomic analyses of the changes in the hepatopancreas between infected and non-infected juvenile lobsters were analyzed by isobaric tags for relative and absolute quantitation (iTRAQ) coupled to synchronous precursor selection (SPS)-based MS3. We identified a total of 636 proteins, being 68 down-regulated and 71 up-regulated proteins. Among the down-regulated proteins, we identified several enzymes involved in the metabolism of hormones and lipids, digestive proteases and glycosidases, while proteins associated with the histone core, protein synthesis, immune response and RNA regulation were up-regulated. Several misregulated enzymes involved in the regulation of neuromodulators were also identified. RT-qPCR assays were used to validate the expression of transcripts encoding for selected differential proteins that were in concordance to proteomic data, as well as the tendency observed in the enzymatic activities of trypsin, chymotrypsin, and glycosidase. In a similar way, we observed glycogen reduction in muscle, and an increase in plasma acylglycerides and glucose, which may be explained by proteomic data. This study provides the first insight into the molecular changes in the hepatopancreas of Caribbean spiny lobsters associated to PaV1 infection. Data provided herein would help to clarify the origin of the molecular misregulations observed at macroscopic level in this host-pathogen interaction.

Restricted access material-ion imprinted polymer-based method for on-line flow preconcentration of Cd2+ prior to flame atomic absorption spectrometry determination

The present paper describes a new restricted access material-ion imprinted polymer for on-line preconcentration of Cd2+ from natural water samples, and simultaneous clean-up of humic acid. Cadmium-imprinted poly(allylthiourea) was synthesized and modified with 2-hydroxyethyl methacrylate (IIP-HEMA) to obtain the restricted access ability. The on-line flow injection system coupled to FAAS (FIA-FAAS) was based on percolation of 20.0 mL of the sample (pH 8.70 and in presence of organic matter) through a mini-column (100.0 mg of IIP-HEMA) at 7.5 mL min−1 flow rate. The elution step was performed using 2.0 mol L−1 HNO3 at 5.0 mL min−1 flow rate. The method provided linearity in the range 0.56–50.00 μg L−1 and limit of detection of 0.17 μg L−1. The preconcentration factor was found to be 37-fold, consumption index of 0.54 mL, preconcentration efficiency of 13.10 min−1 and sample throughput of 21 h−1. The precision of the method was evaluated in terms of intra-day and inter-day repeatability and the relative standard deviation percentage (%RSD) obtained by two-level concentration (2.50 and 40.00 μg L−1) in the presence and absence of humic acid were <5.0%. Low interferences of ions commonly found in water samples as well as the humic acid were observed. The accuracy was attested by addition and recovery tests at two-level of Cd2+ (2.00 and 20.00 μg L−1, both prepared in presence of humic acid) in a real water sample, and the recovery percentages ranged from 93.8 to 108.7%. Cadmium was also analyzed in a certified reference material TORT-2 (lobster hepatopancreas). The method was applied for Cd2+ determination on water after spiking procedure with known concentration, food (linseed, 301.8 ± 15.3 μg kg−1), herbal medicine (Ginkgo biloba L., 221.2 ± 5.8 μg kg−1) and cigarette (77.9 ± 6.3 μg kg−1).

Detection of Paralytic Shellfish Toxins in Southern Rock Lobster Jasus edwardsii Using the Qualitative Neogen™ Lateral Flow Immunoassay: Single-Laboratory Validation.

Paralytic shellfish toxins (PST) are a significant problem for the Tasmanian shellfish and Southern Rock Lobster (Jasus edwardsii) industries, and the introduction of a rapid screening test in the monitoring program could save time and money. The aim was to perform a single-laboratory validation of the Neogen rapid test for PST in the hepatopancreas of Southern Rock Lobster. The AOAC INTERNATIONAL guidelines for the validation of qualitative binary chemistry methods were followed. Three different PST profiles (mixtures) were used, of which two were commonly found in naturally contaminated lobster hepatopancreas (high in gonyautoxin 2&3 and saxitoxin), and the third toxin profile was observed in a few select animals (high in gonyautoxin 1&4). The Neogen test consistently returned negative results for non-target toxins (selectivity). The probability of detection (POD) of PST in the lobster hepatopancreas using the Neogen test increased with increasing PST concentrations. POD values of 1.0 were obtained at ≥0.57 mg STX-diHCl eq/kg in mixtures 1 and 2, and 0.95 and 1.0 for mixture 3 at 0.79 and 1.21 mg STX-diHCl eq/kg, respectively, with a fitted POD of 0.98 for 0.80 mg STX-diHCl eq/kg. The performance of the Neogen test when using four different production lots (ruggedness) showed no significant differences. The results of the validation study were satisfactory and the Neogen test is being trialed within the Tasmanian PST monitoring program of Southern Rock Lobster. The Neogen rapid kit was successfully validated for the detection of PST in Southern Rock Lobster hepatopancreas.

Copper Isotopic Analysis in Geological and Biological Reference Materials by MC‐ICP‐MS

The characterisation of relative copper isotope amount ratios (δ65Cu) helps constrain a variety of geochemical processes occurring in the geosphere, biosphere and hydrosphere. The accurate and precise determination of δ65Cu in matrix reference materials is crucial in the effort to validate measurement methods. With the goal of expanding the number and variety of available geological and biological materials, we have characterised the δ65Cu values of ten reference materials by MC‐ICP‐MS using C‐SSBIN model for mass bias correction. SGR‐1b (Green River shale), DOLT‐5 (dogfish liver), DORM‐4 (fish protein), TORT‐3 (lobster hepatopancreas), MESS‐4 (marine sediment) and PACS‐3 (marine sediment) have for the first time been characterised for δ65Cu. Additionally, four reference materials (with published δ65Cu values) have been characterised: BHVO‐1 (Hawaiian basalt), BIR‐1 (Icelandic basalt), W‐2a (diabase) and Seronorm™ Trace Elements Serum L‐1 (human serum). The reference materials measured in this study possess complex and varied matrices with copper mass fractions ranging from 1.2 µg g−1 to 497 µg g−1 and δ65Cu values ranging from −0.20‰ to 0.52‰ with a mean expanded uncertainty of ± 0.07‰ (U, k = 2), covering much of the natural copper isotope variability observed in the environment.

DETERMINAÇÃO DE MERCÚRIO EM FÍGADO DE TETRÁPODES MARINHOS POR ESPECTROMETRIA DE FLUORESCÊNCIA ATÔMICA ACOPLADA A GERAÇÃO DE VAPOR FRIO (CV-AFS) E ESPECTROMETRIA DE MASSA COM FONTE DE PLASMA INDUTIVAMENTE ACOPLADO (ICP-MS): UMA COMPARAÇÃO SISTEMÁTICA ENTRE AS DUAS TÉCNICAS

DETERMINATION OF MERCURY IN LIVER OF MARINE TETRAPODS BY COLD VAPOR ATOMIC FLUORESCENCE SPECTROMETRY AND INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY IN BIOLOGICAL SAMPLES: A SYSTEMATIC COMPARISON BETWEEN THE TWO TECHNIQUES. This study compares the techniques cold vapour atomic fluorescence spectrometry (CV-AFS) and inductively coupled plasma mass spectrometry (ICP-MS) for the determination of Hg in biological samples (hepatic tissue from marine tetrapods). Acid digestions were performed for the samples and aliquots of them were analysed by ICP-MS and CV-AFS. To minimize the Hg memory effect in its determination by ICP-MS, gold (200 μg L-1 in 5% v v-1 HCl) was added to the sample digests. The detection limits were 0.02 mg kg-1 for ICP-MS and 0.01 mg kg-1 for CV-AFS. Accuracy was assessed by the calculation of the recovery obtained from TORT-3 (lobster hepatopancreas) certified reference material analysis. Accurate results were obtained for both CV-AFS and ICP-MS. The comparison of the results obtained for hepatic tissue with and without lyophilization showed a significant difference among them (at 95% of confidence level), evidencing losses of Hg in the lyophilization process.