Simultaneous speciation analysis of Hg and Se in fish by high-performance liquid chromatography and inductively coupled plasma-mass spectrometry following microwave-assisted enzymatic hydrolysis.

This study reports the development and validation of a new analytical method for simultaneous speciation analysis of Se and Hg in fish muscle. For this purpose, four Se species (selenite/Se(IV), selenate/Se(VI), selenomethionine/SeMet, and selenocysteine/SeCys) and two Hg species (inorganic mercury/iHg and methylmercury/MeHg) were extracted simultaneously by microwave-assisted enzymatic hydrolysis and then separated by HPLC in less than 15 min by using a column with both anion and cation exchange mechanisms and a mobile phase consisting of a mixture of methanol 5% (v/v), 45 mM HNO3, 0.015% 2-mercaptoethanol, and 1.5 mM sodium 3-mercapto-1-propanesulfonate. The separated species of Hg and Se were detected online by inductively coupled plasma-mass spectrometry (ICP-MS). The speciation analysis method was validated by means of the accuracy profile approach by carrying out three series of measurements in duplicate on three different days over a time-span of 3 weeks. The limits of quantification (LOQ) are in the range of 0.010-0.013 mg/kg wet weight (ww) for all selenium species, except for Se(IV) (0.15 mg/kg ww), while the coefficient of variation in terms of intermediate reproducibility (CVR) was < 7%. The LOQ for MeHg was 0.006 mg/kg ww, while the CVR was 3%. The method was successfully applied to the analysis of muscle samples from four different fish species: rainbow trout, tuna, swordfish, and dogfish.

Assessment of the mercury-selenium antagonism in rainbow trout fish.

This study aims at the assessment of mercury (Hg)-selenium (Se) antagonism in fish. For this purpose, rainbow trout fish (Oncorhynchus mykiss) were exposed to methylmercury (MeHg) under controlled conditions, in the presence or absence of selenomethionine (SeMet) using an in-house prepared diet (enriched with MeHg and SeMet at 0.2 µg/g and 5.0 µg/g, respectively). The total duration of the exposure study was 3 months. Fish was sampled and analysed for total Se (SeT) and total mercury (HgT) content after 1, 2 and 3 months of exposure. Six feeding protocols were compared, depending on the exposure type: (i) no MeHg nor SeMet exposure (control group); (ii) exposure to SeMet solely; (iii) exposure to MeHg solely; (iv) exposure to both MeHg and SeMet; (v) exposure first to MeHg during 1 month and then to SeMet during 2 months and (vi), exposure to SeMet during 1 month and then to MeHg for 2 months. The levels of SeT and HgT in the fish (control and supplemented with MeHg/SeMet) were measured by inductively coupled plasma-mass spectrometry (ICPMS). Steadily (linear) bioaccumulation of MeHg in the fish muscle occurred when the fish were exposed individually to this species during the period. The bioaccumulation of MeHg is diminished when the fish are firstly exposed to SeMet and then to MeHg, hence indicating the MeHg detoxification due to SeMet supplementation.

Hemograma e proteinograma de cutias (Dasyprocta sp. ) hígidas, criadas em cativeiro: influência do sexo e da idade / Haemogram and proteinogram of healthy agouti (Dasyprocta sp. ) raised in captivity: influence of gender and age

Determinaram-se os perfis do hemograma e do proteinograma de 24 cutias (Dasyprocta sp.) saudáveis, criadas em cativeiro, e avaliaram-se a influência de sexo e de idade e a interação sexo-idade. O delineamento foi inteiramente ao acaso em arranjo fatorial 2 x 4 (dois sexos e quatro faixas etárias), com três repetições. Os valores do hemograma e do proteinograma foram: leucócitos totais: 7,24±2,52 (x10³/µl), basófilos: 0,11±0,2 (x10³/µl), eosinófilos: 0,32±0,2 (x10³/µl), segmentados: 2,5±1,22 (x10³/µl), linfócitos: 3,58±1,52 (x10³/µl), monócitos: 0,76±0,47 (x10³/µl), hemácias: 6,51±0,83 (x10(6)/µl), hematócrito: 43,58±3,41 por cento, hemoglobina: 12,71±1,04g/dl, volume corpuscular médio: 67,61±7,52ml, concentração de hemoglobina corpuscular média: 29,19±1,61 por cento, plaquetas: 150,08±63,39 (x10³/ml), proteínas totais: 6,04±1,77g/dl, albumina: 2,07±0,79g/dl e globulinas: 3,97±1,54g/dl. Os parâmetros relativos à série vermelha e ao proteinograma não diferiram quanto ao sexo ou idade, e não houve interação sexo-idade. Os valores de linfócitos foram mais baixos entre os animais mais velhos.

The profiles of hemogram and proteinogram of healthy agouti (Dasyprocta sp.) grown in captivity, in Piauí State, Brazil, were determined, as well as the influence of gender and age factors and the relationship between sex-age them. A completely randomized design was used in a factorial arrange 2x4, two genders and four ages, totaling 24 animals. The mean values of the hemogram were: erythrocytes = 6.51±0.83 (x10(6)); hematocrit = 43.58±3,41 percent; hemoglobin = 12.71±1,04g/dl; mean corpuscular volume = 64.61±7.52μl; mean corpuscular hemoglobin concentration = 29.19±1,61 percent; platelets= 150.08±63.39 (x10³/μl); white blood cells = 7.24±2.52 (x10³/μl); basophils = 0.11±0,2 (x10³/μl); eosinophils = 0,32±0,2 (x10³/μl); neutrophils = 2.5±1,22 (x10³/μl); lymphocytes = 3.58±1.52 (x10³/μl); and monocytes = 0.76±0.47 (x10³/μl). The mean values of the proteinogram were: total serum proteins = 6.04±1.77g/dl; albumin = 2.07±0.79g/dl and globulin = 3.97±1.54g/dl. Neither gender nor age influenced the results of the studied parameters. Association between gender and age was not verified. The values of lymphocytes were lower in older animals.

Níveis iônicos e enzimáticos de cutias (Dasyprocta sp.) hígidas, criadas em cativeiro, influência do sexo e da idade / Ion and enzymatic levels of healthy agouti (Dasyprocta sp.) raised in captivit. Influence of gender and age

Determinou-se o perfil do ionograma e enzimas hepáticas de cutias (Dasyprocta sp.) saudáveis, criadas em cativeiro, como também se avaliou a influência de sexo, idade e interação sexo-idade. Foi adotado um delineamento inteiramente ao acaso, em arranjo fatorial 2 x 4 (dois sexos e quatro faixas etárias), com três repetições, totalizando 24 cutias. Foram determinados os valores para o cálcio (Ca), fósforo (P), cloretos (Cl), aspartato aminotransferase (AST), alanina aminotransferase (ALT), fosfatase alcalina (FA) e gama-glutamiltransferase (GGT). Os valores médios obtidos foram: Ca= 7,62+2,59mg/dl; P= 3,91+1,41mg/dl; Cl= 58,63+16,45mg/dl; AST= 119,54+79,35UI/ml; ALT= 28,08+15,53UI/ml; FA= 26,95+14,01UI/ml e GGT= 25,34+19,44UI/ml. O valor de P foi maior nas fêmeas e da FA nos machos. Os níveis de FA diminuíram com o aumento da idade.

This research studied the profile of the ionogram and hepatic enzymes of healthy agoutis (Dasyprocta sp.) raised in captivity as well as evaluated the influence of gender, age and interaction gender-age. It was used a completely randomized design, in a factorial arrangement of 2 x 4 (two genders and four age groups), with three repetitions, totaling 24 agoutis. The values were determined for calcium (Ca), phosphorus (P), chlorides (Cl), aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT). The mean values were: Ca= 7.62±2.59mg/dl; P= 3.91±1.41mg/dl; Cl= 58.63±16,45mg/dl; AST= 119.54±79.35UI/ml; ALT= 28.08±15.53UI/ml; ALP= 26.95±14.01UI/ml, and GGT= 25.34±19.44UI/ml. The value of P was larger in females and ALP in males. As the age increased, levels of ALP decreased.