Abstract:

A total of 17 common metal elements including Na, K, As, Pb, Cd, Sn, Ti, Mg, Fe, Cu, Mn, Zn, Ca, Al, Ni, Cr
and Ba were measured in fermented grains, distillery spent wash and liquor samples using inductively coupled plasma
mass spectrometry (ICP-MS) coupled with microwave digestion before and after distillation. SPSS was applied to analyze
the origin of related elements in liquor samples by t-test. The results suggested that more than 94% of the overall metal
elements remained in the wine lees after distillation, while less than 6% metal ions were transferred into either spent wash
or the resultant liquor. Heavy metal ions such as Pb, Mn and Cr showed lower transfer ratio than Na, K, Ca and Mg, which
significantly reduced the possibility of transfer of those hazardous components from the polluted raw materials to liquor. It
was also found that Ca, Cu, K, Mg, Na, Zn and Ba in liquor samples were mainly from wine lees and the equipment used in
the distillation process would introduce Fe, Ni, Al and Sn, and even Pb and Cr to the liquor.

Key words: Luzhou-flavor liquor, heavy metal ions, distillation, microwave-assisted digestion, inductively coupled plasma mass spectrometry (ICP-MS)