Naslov
Proficiency Testing: Experience from Croatia on the issues of heavy metals determination in marine sediment

Autori
Matek Sarić, Marijana ; Grzunov, Judita

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), stručni

Izvornik
Proceeding of the 1 st International Proficiency Testing Conference / - Bukurešt, 2007, 177-182

ISBN
978-973-8132-65-8

Skup
1 st International Proficiency Testing Conference

Mjesto i datum
Sinaia, Rumunjska, 11.10.2007. - 13.10.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
proficiency testing; international intercalibrations; marine sediment; heavy metals

Sažetak
Laboratories may check the accuracy of heavy metals measurements in marine sediment by taking part in international intercalibrations. Measurement methods for all metals must be validated and laboratory must implement good laboratory practice to avoid a risk of contamination and loss of analytes during pretreatmant process. A risk of contamination should be avoided by using reagents suprapur or of analytical grade and also Milli-Q deionised water (<1µSi) for preparing all labware and samples. The best way of cleaning digestion teflon vessels and their caps is to soak them overnight in a detergent solution, rinse throughly with tap water, then with Milli-R water (< 60 µSi). Afterward fill the vessels with 5 mL of nitric acid (HNO3 conc), close and put them in the microwave-oven. The program may be the same as digestion program. Empty the vessels (acid can be kept for more cycles of cleaning) and rinse them carefully with Milly-Q water. Leave them to dry under a laminar flow hood. Once dried, the vessels should be closed and put into polyethylene bags to prevent the risk of contamination prior to use. Sediment is dry sample so it should be homogenizated (shaking 2 min) before weighing. Before opening the bottle, wait a few minutes and accurattely weigh the sample in labeled teflon vessel. For moisture content determination at least two samples should be prepared (in separated cups, not in digestion vessels). At least one certified reference material should be used and prepared in duplicate for each digestion batch (12 places). The digestion is prepared in a similar manner as a sample. A reference material of similar composition and concentration range should be used. At least two blanks should be prepared for each batch of analysis. Sediment sample must be treated in closed teflon vessels with hydroflouric acid (HF) in combination with (HNO3). The use of HF is essential because it is the only acid that compleatly dissolves the silicate lattices and releases all the material.

Izvorni jezik
Engleski

Znanstvena područja
Javno zdravstvo i zdravstvena zaštita, Prehrambena tehnologija

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