Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Determination of Toxic Metal Accumulation in Shrimps by Atomic Absorption Spectrometry (aas)

K. Fatema
Department of Physics, Jahangirnagar University, Savar, Dhaka, Bangladesh.

K. Naher
Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, GPO Box No. 3787, Savar, Dhaka-1000, Bangladesh.

TR Choudhury
Atomic Energy centre, 4 Kazi Nazrul Islam Avenue, P.O. Box No. 164, Ramna, Dhaka, Bangladesh.

MP Ali
Laboratory of Biotechnology, Gradaute School of Science and Technology, Shizuoka University, Japan.

Abstract/ Executive Summary:

A study was carried out to assess the levels of lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), and mercury (Hg) in different shrimp species. Atomic absorption spectrometry was used to estimate and evaluate the levels of these metals from 11 shrimp samples. The results of this study showed that the average concentrations detected ranged from <0.1 to 0.202, <0.1 to 0.416, <0.1 to 0.156, <0.1 to 0.21 and <0.1 to 0.28 mg/kg for Pb, Cd, As, Cr and Hg, respectively in river shrimps. In case of Gher, it was ranged from <0.1 to 0.267, <0.1 to 0.166, <0.1 to 0.156, <0.1 to 0.21 and <0.1 to 0.228 mg/kg for Pb, Cd, As, Cr and Hg, respectively. The results showed that Pb concentration for both river and Gher samples lies between EU and IAEA limits, Cd concentration in river samples were higher than both EU and IAEA limits. Arsenic was observed only in one river sample that was also below the recommended level. Hg concentration for both Gher and river samples are less than the EU permissible limit. The study highlights the presence of toxic metals but were below the recommended tolerable levels in shrimp of Bangladesh and thus might not constitute a health hazards for the consumers.

Keywords: Heavy metals; Fish; Contaminants; Shrimps

Location: Tala upazila, Satkhira.

Start Date:

End Date:

Program Area: Food Safety and Security

Commodity: Shrimp, Heavy metal

Objectives:

1. To estimate the heavy metal accumulation in shrimps

2. To evaluate the level of toxicity as a step to overcome the problem.

Methodology:

Six shrimp samples were collected from Kobadak River and five shrimp samples were collected from local Gher of Tala upazila at Satkhira. The famous local name of these shrimps is Bagda, Golda, Chali, Rosnai and Harina. At first eleven shrimp samples were individually cleaned by de-ionized water and the head was removed from the flesh with a stainless steel knife. Collected shrimp samples were allowed to dry in an electric oven at 80ºC until having constant weight. After drying the samples were crushed into fine powder with an agate mortar and pestles. After crashing the sample into fine powder, samples were transferred into ultra clean small polyethylene packet. Samples were prepared for the purpose of: Determination of the toxic element (Hg) in the shrimp samples by cold vapor atomic absorption spectroscopy (CV-AAS). Determination of the toxic element (As) in the shrimp samples by hydride generation atomic absorption spectroscopy (HG-AAS). Determination of the toxic elements (Pb, Cd, Cr) in the shrimp samples by graphite furnace atomic absorption spectroscopy (GF-AAS). Analytical conditions for determination of trace amounts of As, Pb, Cd, Cr and Hg by AAS have been optimized in our previous study. For present study to determine Cr, Cd, Pb, As and Hg, micro wave digestion was used for sample preparation. A portion of 0.5 g of ground sample was transferred directly to the flasks of the microwave oven (CEM MARS 5) and 6 ml of supra pure nitric acid was added. There is no heating procedure for CVAAS and HFAAS. But there is a heating program for GFAAS. The heating program employed was the one proposed in the user’s manual. The following three steps temperature program was applied: 180ºC with a ramping time 10 min; and cooling time 10 min. For 6 or more vessels 1200W can be used. The resulting extracts were redissolved in 10 ml of ultra pure water for subsequent analysis by GFAAS. For certified reference material (Oyster tissue) an amount of 0.5 g of sample was digested in microwave as described for the shrimp samples. Calibration curve was made for each element and concentration of the element in each sample was determined from the respective calibration curve of the element. A Varian (Model no. Varian, DuoAA240FS and AA80Z) GFAAS was used for this experiment. The solutions provided by the sample treatment and those used to construct the calibration curves, made in water containing 1.0% (v/v) HNO₃, were injected in the graphite furnace atomic absorption spectrometer. The temperature program and resonance lines used for measurement are shown. Volume of sample or standard solution (Oyster tissue) of 20 µl, depending on the metal to be analyzed, which was supplied with 5 µl of 1% H₃PO₄ for Pb, 1% NH₄H₂PO₄ for Cd as modifier, was used in each run. For Cr, matrix modifier was not required and the volume of sample or standard solution injected was 15 µl. Determination of Pb, Cd and Cr (mg/kg) in certified reference materials Oyster tissue is shown. CVAAS technique was used for determining the concentration of Hg in shrimp sample. Using ANALYTIK JENA (novAA350). A volume of digestion sample of 4 ml, depending on the metal to be analyzed, which was supplied with 1 ml HCl and 15 ml DI for Hg as modifier. There were two chamber, Reductant chamber with 0.3% NaBH 4 and 0.1% NaOH and HCl acid chamber with 3% HCl. The wave length of Hg was 253.7 nm. The solutions provided by the sample treatment and those used to construct the calibration curves. HGAAS technique was used for determining the concentration of As in shrimp samples using VarianAA240. A volume of digestion sample of 2 ml, depending on the metal to be analyzed, which was supplied with 3M HCl and 1% KI, 1% of ascorbic acid for Hg as modifier. The total volume of the liquid sample was 20 ml. The wave length of As was 193.7 nm. The solutions provided by the sample treatment and those used to construct the calibration curves. The analytical methods combining closed digestion, followed by determination with GF-AAS, CV-AAS and HG-AAS was developed for study of arsenic, cadmium, lead, chromium and mercury at very low levels in shrimp sample. The detection limits for are Pb, Cd, Cr and As are <0.1 mg/kg and for Hg <0.3 mg/kg under the study experimental conditions.

Source of Information: J Environ Anal Chem 2015, Vol: 2(3), ISSN: JREAC

Article Link (Online Journal): http://dx.doi.org/10.4172/ jreac .1000140

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

The result showed that Bangladeshi shrimp contained low concentration levels of toxic elements. The results show that, Pb concentration for both river and Gher samples lied between EU and IAEA limits, Cd concentration in river samples were higher than both EU and IAEA limits. Arsenic was observed only in one river sample. Finally, Hg concentration for both Gher and river samples were less than the EU permissible limit. These indicated that, the probability of contamination with heavy metals in Gher was lower than river. So, it could be said that, comparatively shrimp produced in Gher is safeer to eat than those of river.

Knowledge Management: Journal