Re: Mercury auto analysers

From: Roy Palmer (palmerroy@hotmail.com)
Date: Sun Mar 05 2006 - 02:31:45 PST

  • Next message: Liz Brown: "labeling"

    Fw: Testing each fish for mercuryIve attached all the info I can find about MASI, Safe Harbor etc

    Seems precious short of technical information to me

    Cheers roy
      ----- Original Message -----
      From: E. Jerry Oliveras, Jr.
      To: seafood
      Sent: Friday, March 03, 2006 2:34 PM
      Subject: Re: Mercury auto analysers

      As an analytical chemist and food scientist of some experience, I spent some time trying to find out anything about how the MASI system works to satisfy my curiosity but could not. Anyone know anything about the nuts and bolts of this new in plant desk top tool for trace level mercury tests in fish? Does it measure total mercury, methyl mercury, what detection limit can it achieve, how reliable is the data generated, false negative rate, etc. ?? I am very curious about this procedure esp. when I know what is involved in regulatory test methods for total and methyl mercury at ppb and lower levels.
      thanks
      E. Jerry Oliveras, Jr. - Consulting Chemist & Food Scientist
      1066 Stannage Avenue, Albany, CA 94706
      phone / FAX: 510-524-9199 Cell: 510-520-0755
      homepage: ejoliverasjr@sbcglobal.net/">http://geocities.com/ejoliverasjr@sbcglobal.net/

      ----- Original Message -----
        From: Roy Palmer
        To: seafood
        Sent: Wednesday, March 01, 2006 5:22 PM
        Subject: Fw: Mercury auto analysers

        ----- Original Message -----
        From: Padula, David (PIRSA - SARDI)
        To: evertliewes@hotmail.com
        Cc: palmerroy@hotmail.com
        Sent: Thursday, March 02, 2006 11:27 AM
        Subject: Mercury auto analysers

        Dear Evert,

        I am a Government researcher in Australia - we conduct large amounts of residue testing included for canned fish products for mercury in addition to other contaminants dioxin, PCBs, pesticides and veterinary medicines in Southern Bluefin tuna. This testing is done as a delegated agent of the National Residue Survey (NRS) - this data is used to fulfil trade access requirements in overseas markets around the world. Some of our reports are available on the internet at www.sbtuna.com under the "residues" link. Our main program details can be found at www.sardi.sa.gov.au under the "Food Safety" link. We are currently doing some work looking at the distribution of mercury in tuna - as the fat content of the tuna varies depending on which cut you are looking at i.e. o-toro vs. akami then this can have an effect on the level of mercury found - and hence the conclusions about the safety of that fish. The EU has specific sampling protocols that must be followed for product entering the EU for reporting of residue results.

        The cost for analysis of total mercury in fish samples that we pay is $25 (Australian dollars) per sample. These systems such as you have highlighted below do need to be validated and calibrated. I don't know the specific system in detail but you would want to ask a lot of questions about its robustness to handle high fat content samples, potential interferences, limits of detection, linearity of response, reproducibility of results, calibration, acceptance of data by importing country competent authorities, what technical training is needed, how much do the reagents cost, what is the operating cost of the instrument and all the disposable products needed, glassware, are the waste products safe to dispose down the sink etc. I have seen a different automated system promoted at a conference in New Zealand last year.

        You need to remember there are different chemical forms of mercury - the US FDA MRL is set based on methyl mercury. Methyl mercury costs about $250/sample to test for and is quite difficult to do. Is this instrument able to test specifically total mercury or methyl mercury or other organic forms of mercury? I have some doubts about these rapid mercury analysis do it yourself type kits - they generally are quite expensive in the order of $200,000 US to buy - plus the OH&S issues of handling mercury standards and ongoing costs for reagents and consumables etc. We only use accredited laboratories for our testing to satisfy product integrity requirements. Mercury analysis is quite a specialised area and there has been many decades of work put into developing classical methods such as AA or ICP-MS which have stood the test of time. If this instrument is so good let them publish a study by an independent group on a comparison of their instrument vs. the classical methods and quantify the costs in a peer reviewed journal.

        There are some semi automated mercury analysers using flow injection analysis which are quite robust - however all of these instruments require a lot of technical training and experience to operate. You really need to look at how many samples/year are you analysing and make a judgment as to whether it's worth setting up a lab to do the testing yourself. Are you testing individual fish or composite samples?

        Cheers,
        David

        ____________________________

        David Padula

        Research Scientist - Epidemiology & Sampling

        SARDI FOOD SAFETY PROGRAM

        33 Flemington Street

        Glenside SA 5065

        Phone: (08) 8207 7939

        Mobile: 0422 000 020

        Fax: (08) 8207 7854

        Email: padula.david@saugov.sa.gov.au

        _____________________________

        The information in this e-mail and attachments (if any) may be confidential and/or legally privileged. If you are not the intended recipient, any disclosure, copying, distribution or action taken is prohibited. SARDI, The South Australian Research and Development Institute, is the research division of Primary Industries and Resources (SA)

        ----- Original Message -----
        From: "Evert Liewes" <evertliewes@hotmail.com>
        To: "Liz Brown" <bfeab@uaf.edu>; "seafood" <seafood@ucdavis.edu>
        Sent: Wednesday, March 01, 2006 3:03 PM
        Subject: Testing each fish for mercury

    > Hello
    >
    > I read the article and was surprised to read the that Micro Analytical
    > Systems has a system available to test large numbers of fish very quickly.
    > We produce canned tuna and take large numbers of samples for mercury
    > testing. Based on a risk assesment we will sample all lots of incoming
    > fish. When we find higher mercury levels, mostly associated with larger
    > fish, we do more testing in order to understand how the mercury is
    > distributed with fish size. If mercury levels are high (over 0,5 mg/kg) we
    > size the fish more accurately and sample and test again. Subsequently
    > large fish may be sampled individually and rejected.
    >
    > This works well, but generates large numbers of samples. A fast working
    > testing system therefore is attractive. How accurate is the system of
    > Micro Analytical Systems? What does it cost per analysis, compared to the
    > traditional methods? Any info will be appreciated.
    >
    > Evert Liewes
    > Princes Tuna Maurititus
    >
    > ---- Original Message -----
    > From: "Liz Brown" <bfeab@uaf.edu>
    > To: "seafood" <seafood@ucdavis.edu>
    > Cc: "Allison Rice" <fnar@uaf.edu>; "Bristol BayTimes"
    > <bbtimes@nushtel.com>; "Bob Shavelson" <bob@inletkeeper.org>
    > Sent: Wednesday, March 01, 2006 1:56 AM
    > Subject: Testing each fish for mercury
    >
    >
    >> http://www.latimes.com/business/la-fi-fish27feb27,1,3246852.story?ctrack=1&cset=true
    >>
    >>
    >>
    >>
    >> --
    >> Liz Brown
    >> Marine Advisory Program
    >> University of Alaska Fairbanks
    >> PO Box 1549
    >> Dillingham, AK 99576
    >> 907-842-1265
    >> Fax 907-842-3202
    >> www.uaf.edu/map
    >>
    >>
    >
    >





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