Anyone treating Hg the same as other metals, i.e., dilute nitric acid, is not mentioning having calibration and QC problems if they even run QC.
I have diluted blood in base with a sulfur ligand chelating agent for Hg in blood. You would not need Triton X100 for honey. Notice that to maintain standard stock stability, we diluted in nitric acid + HCl prior to diluting further into TMAH base:
McShane, W.J., Pappas, R.S., Wilson-McElprang, V., and Paschal, D. A rugged and transferable method for determining blood cadmium, mercury, and lead with inductively coupled plasma-mass spectrometry, Spectrochim. Acta B 2008;63:638-644.
If you prefer acid, You do NOT want to add gold AND hydrochloric acid. Gold is an easily reduced soft acid cation, the same as Hg. That is why some people use gold and add it in excess, to increase chance that gold will be reduced in preference to Hg due to the excess. Because gold and Hg have similar chemistry, if you add HCl, the gold competes with Hg for the Cl- ligands, and remember, it is in excess. "If one is good, both would be better," does not work as well.
A better option is to reduce the nitric acid if you can to 1% or less and use up to 3% HCl. As an alternative, you can do even better with a sulfur ligand (NO GOLD!) like 0.1% high metals purity L-cysteine such as sold by Sigma. Do remake your standards every month or so, because the nitric acid oxidizes the cysteine.
R. Steven Pappas, Ph.D.
Team Lead, Tobacco Inorganics Group
Centers for Disease Control & Prevention
4770 Buford Highway, NE
M.S. F44, Building 110
Atlanta, GA 30341-3717, USA
From: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's). <[log in to unmask]> On Behalf Of Paula Zelanko
Sent: Thursday, August 2, 2018 10:20 AM
To: [log in to unmask]
Subject: Hg in honey
I'm starting a new project looking at Hg in honey. All of the relevant literature I've been able to find, seems to treat Hg the same as the other metals. No special run conditions. I remember reading somewhere you need HCl and gold in your wash solution when running Hg due to carry over. I've never run honey or Hg before, can anyone lend some in site or point me to some papers?
ThanksPaula ZelankoMass Spec Laboratory ManagerDrexel University