Determination of inorganic and total mercury in biological tissues by electrothermal vaporization inductively coupled plasma mass spectrometry

A rapid method for the determination of total and inorganic mercury in biological tissues is presented using electrothermal vaporization inductively coupled plasma mass spectrometry (ETV ICP\u2013MS). Samples were solubilized using tetramethylammonium hydroxide. For the determination of total mercury sample aliquots (10 \ub5l) are dried and vaporized into the plasma. For the determination of inorganic mercury, iodoacetic acid, sodium thiosulfate and acetic acid are added to the sample, cleaving the methylmercury from the tissue. Volatile methylmercury iodide is formed and removed from the ETV as the sample dries, leaving only inorganic mercury to be quantified. A limit of detection of 0.05 \ub5g g -1 in solid samples was obtained. National Research Council of Canada reference materials DORM-2 (dogfish muscle), DOLT-2 (dogfish liver) and TORT-2 (lobster hepatopancreas) were used to assess the accuracy of the method.NRC publication: Ye

Determination of ultratrace levels of heavy metals in arctic snow by electrothermal vaporization inductively coupled plasma mass spectrometry

Application of electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) to the direct determination of trace heavy metals in surface samples of Arctic snow is described. Limits of detection by ETC-ICP-MS are in the fg range, viz., 29, 57, 86, 120, 140, 360, 420, 470, 870 and 3200 for Tl, Cs, Pb, Mn, Co, V, Cu, Ni, Cd and Cr, respectively. Direct quantification against simple aqueous standards is feasible using NaCl solution as a carrier. The latter was obtained in a high-purity form through dilution of the sea-water reference material National Research Council of Canada (NRCC) NASS-3. Assessment of accuracy was accomplished by analysis of the river water reference material SLRS-2 (NRCC) and by comparative analysis of the samples by electrothermal atomization atomic absorption spectrometry.NRC publication: Ye

Fatty acid–induced NLRP3-ASC inflammasome activation interferes with insulin signaling

High-fat diet (HFD) and inflammation are key contributors to insulin resistance and type 2 diabetes (T2D). Interleukin (IL)-1β plays a role in insulin resistance; yet, how IL-1β is induced by fatty acid with HFD, and how this alters insulin signaling is unclear. We show that the saturated fatty acid, palmitate, but not unsaturated oleate, induces the activation of NLRP3-PYCARD inflammasome, causing caspase-1, IL-1β, and IL-18 production. This involves mitochondrial reactive oxygen species and the AMP-activated protein kinase and ULK1 autophagy signaling cascade. Inflammasome activation in hematopoietic cells impairs insulin signaling in several target tissues to reduce glucose tolerance and insulin sensitivity. Furthermore, IL-1β affects insulin sensitivity via TNF-independent and dependent pathways. These findings provide insights into the association of inflammation, diet and T2D