Dear Mohamed A. A. Mahdy,

in 100x and in 600x the pic is same, except the area of field is bigger

Hi, Hope you are well. Rather little information.

[Please Google: Guambe, Mars and Day (Nuclear Instruments and Methods & International Journal of PIXE)]

top left. Appears to be ctenoid scale. top right-growth deformation. bottom left-elemental shortage. Bottom right- particle formation. (Maybe due to inadequate cleaning) Now please let me know if..

The SEM you used, was it equipped with an EDX detector? If so, determine the composition of the particles in bottom-left image. Could be As oxide. Just remember the the scale consists of keratin, CaCO3 etc. If you have access to PIXE (let me know where you are. I will know people nearby) then perform a scan of the scale the same manner we did. depending on your SEM instrumentation, you should be able to do scanning with SEM too. (Please note the minimum detection limits: For SEM its 500 ppm, but for PIXE it is 1 ppm). You will find the distribution of As in the scale. More importantly, I hope you have some of the fish organs available. Homogenize, freeze dry these, then press into tablets, coat with carbon (about 10 nm thick) and perform SEM and or PIXE analysis. You will be able to see how the arsenic was incorporated into the scale matrix, if it forms similar distribution with other elements etc. And from these establish kinetics of the incorporation. On the latter; we still need to do this with our data, so just verbal input form me here at this moment.

I hope this will help.

Regards,

Johan

Respected Johan Dr Andre Mars,

Thank you very much for your valuable information and putting my doubts into clarity about those particles on the fish scale following As-exposure, by saying that they could be Arsenic oxide.

But you've said about the top -right picture- growth deformation..

Is that means about the ray structure deformation of the scale?

But it is a control one...

Should i repeat it?

And what is the meaning of elemental shortage in bottom-left pic?

And I'm staying at Kolkata, West Bengal, India and I did my SEM analysis from Burdwan University, Burdwan, West Bengal, India.

I'll definitely try to understand the detector mechanism as you tell.

And your valuable suggestion about my future plan with SEM, is really an added benefit..

Thank you a lot..

Moreover, Sir, can I get any paper on effect of arsenic on fish scale?

Eagerly waiting for your answer.

Thanking you