en A modified method for the determination of organic mercury in biota [great cormorants (phalacrocorax carbo)] by advanced mercury analyzer عمومى General پژوهشي Research <span style="font-weight: bold">Background: </span>Contagion of aquatic ecosystems to heavy metals especially mercury (Hg) has risen concerns about healthiness of marine organisms. Organic mercury compounds are highly toxic for animals, and its detection in various samples is frequently needed. In present study we have described a new method for measurement of organic mercury and total mercury concentration in great cormorants (phalacrocorax carbo) of southern coasts of Caspian Sea. Also, resultant values have been compared with world health standards. <br><span style="font-weight: bold">Methods:</span> 18 great cormorants were hunted randomly in southern coasts of Caspian Sea during March 2009. Analysis of organic and total mercury was performed on samples from their liver, kidney and muscle, with Advanced Mercury Analyzer (Model Leco, AMA 254) for the first time in Iran. This method can be used for others biota. <br><span style="font-weight: bold">Results:</span> Mean concentrations of total mercury were 5.67, 3.59 and 2.26 mg/kg in animal liver, kidney and muscle respectively from which 82, 79 and 58 percent were comprised from organic mercury respectively. Comparison of resultant figures showed statistically significant differences (P<0.05) but no differences were found between different sexes (P=0.69). <br><span style="font-weight: bold">Conclusion: </span>Total mercury concentrations in tissues of great cormorant were outstandingly higher than WHO, FAO and EPA standards. It is a serious threat for end users of the bird meat especially insubstantial humans. Great cormorant, total mercury, Organic mercury, AMA 254, Caspian Sea Great cormorant, total mercury, Organic mercury, AMA 254, Caspian Sea 357 361 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-2-19&slc_lang=en&sid=1 Jaber Aazami جابر اعظمی 10031947532846003243 10031947532846003243 No M. Sc. Student, Department of Environment, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Noor, Iran M. Sc. Student, Department of Environment, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Noor, Iran Abbas Esmaili- Sari عباس اسماعیلی ساری 10031947532846003244 10031947532846003244 No Prof, Department of Environment, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Noor, Iran Prof, Department of Environment, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Noor, Iran Nader Bahramifar نادر بهرامی فر 10031947532846003245 10031947532846003245 No Associate. Prof, Department of Chemistry, Payam noor University, Sari, Iran Associate. Prof, Department of Chemistry, Payam noor University, Sari, Iran Seyed Mahmoud Ghasempouri سید محمود قاسم پوری 10031947532846003246 10031947532846003246 No Lecturer, Department of Environment, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Noor, Iran Lecturer, Department of Environment, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Noor, Iran Amir Mohammad Kazemifar امیرمحمد کاظمی فر j.aazami@modares.ac.ir 10031947532846003247 10031947532846003247 Yes Assistant prof. M.D., Qazvin University of medical sciences, Qazvin; Legal Medicine Research Center, Tehran, Iran Assistant prof. M.D., Qazvin University of medical sciences, Qazvin; Legal Medicine Research Center, Tehran, Iran