『Abstract
A test comparing concentrations of 57 chemical elements (Ag,
Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu,
Fe, Ga, Gd, Ge, Hf, Ho, I, K, la, Li, Lu, Mg, Mn, Mo, Na, Mb,
Nd, Ni, Pb, Pr, Rb, Sb, Se, Sm, Sn, Sr, Ta, Tb, Te, Th, Ti, Tl,
Tm, U, V, W, Y, Yb, Zn and Zr) determined by inductively coupled
plasma quadrupole mass spectroscopy (ICP-QMA) in 294 samples of
the same bottled water (predominantly mineral water) sold in the
European Union in glass and PET bottles demonstrates significant
(Wilcoxon rank sum test, α=0.05) differences in median concentrations
for Sb, Ce, Pb, Al, Zr, Ti, Th, La, Pr, Fe, Zn, Nd, Sn, Cr, Tb,
Er, Gd, Bi, Sm, Y, Lu, Dy, Yb, Tm, Nb and Cu. Antimony has a 21×
higher median value in bottled water when sold in PET bottles
(0.33 vs. 0.016 μg/L). Glass contaminates the water with Ce (19×
higher than in PET bottles), Pb (14×), Al (7×), Zr (7×), Ti, Th
(5×), La (5×), Pr, Fe, Zn, Nd, Sn, Cr, Tb (2×), Er, Gd, Bi, Sm,
Y, Lu, Yb, Tm, Nb and Cu (1.4×). Testing an additional 136 bottles
of the same water sold in green and clear glass bottles demonstrates
an important influence of colour, the water sold in green glass
shows significantly higher concentrations in Cr (7.3×, 1.0 vs.
0.14 μg/L), Th (1.9×), La, Zr, Nd, Ce (1.6×), Pr, Nb, Ti, Fe (1.3×),
Co (1.3×) and Er (1.1×).
One hundred and twenty-six bottles of three different materials
(glass, hard PET and soft PET) in 5 principal colours (clear,
light and dark green and blue, brown) were subsequently washed
and then filled with high purity water (18.2 MΩ cm). A portion
of the bottles where left at the original average pH of the water
(pH 6.5) while the remaining bottles were acidified to pH 3.5
with HNO3. Concentrations of the same 57
elements as above were determined after 1, 2, 3, 4, 5, 15, 30,
56, 80 and 150 days of leaching. Results substantiate the observations
from the direct comparison of the same water sold in different
bottle types (colour). For most elements leaching is enhanced
at pH 3.5, and dark coloured bottles leach more than clear bottles,
independent of bottle material.Values are still on the increase
at the end of the test at 150 days. At that date the leachates
showed a maximum concentration of 0.45 μg/L Sb, 0.3 μg/L Ce, 0.61
μg/L Pb, 68 μg/L Al and 0.06 μg/L Cr (all in glass at pH 3.5).
None of the leachates approaches the maximum concentrations for
drinking water as defined in European jurisdiction.』
1. Introduction
2. Materials and methods
2.1. Laboratories and instrumentation
2.2. Laboratory procedures - leaching test
2.3. Detection limits
2.4. Quality control
2.5. Data analysis
3. Results
3.1. Direct comparison of the same water sold in glass and
PET bottles
3.2. Influence of colour - direct comparison of the same water
sold in clear and in green glass bottles
3.3. Bottle leaching
4. Discussion
5. Conclusion
Acknowledgements
References