Antimony and other trace element concentrations in the samples that were measured at the beginning of the study were all below the promulgated standards, except for Barium. Higher temperatures and longer storage times had a substantial effect (p ≤ 0.05) on the increase of Sb and Al concentrations, while, a decrease was observed in case for Fe.
Westerhoff et al.  showed that high storage temperatures and sunlight exposure increased the leakage of antimony into the bottled waters. Antimony concentration in samples was 0.095 - 0.521 ppb which was lower than that MCL recommended by the United States Environmental Agency (USEPA). The initial mean concentrations were 0.195 ± 0.116 ppb, and after 3 monthas period at 22°C rose to 0.226 ± 0.160 ppb. The amounts of Sb exceeded the MCL in the following conditions: 60°C in 176 days, 65°C in 38 days, 70°C in 12 days, 75°C in 4.7 days, 80°C in 2.3 days and 85°C in 1.3 days .
In this study, the average Sb concentrations were approximately 1.01 ± 0.59 ppb at the initial stage of the experiments, and by the end of the study (after 8 weeks) at room temperature (25 ± 2.6°C) rose to 2.54 ± 1.58 ppb. In case of 65°C, samples 3 and 4 which had the highest initial Sb content, after a two week periods exceeded the MCLs. while the other samples remained below the MCL. Whereas, as the temperature rose to 80°C after two days the Sb amounts exceeded the MCL for samples 3 and 4, while for the other samples it was observed after day three.
Various experiments by Xiaoliang Cheng et al.  demonstrated that 16 trace elements including Sb were leaked into the bottled waters tested in the following conditions, cooling with ice-cold water, warming by boiling, microwave, incubation at low pH, outdoor with sunlight irradiation and storage inside the automobiles. The study established that warming by boiling and microwave could considerably augment the leaching process of Sb into water and in some cases exceeded the MCL levels. However, both incubation at low pH and also cooling with ice-cold water, revealed no significant effects; while the outdoor with sunlight irradiation and sunlight exposure, and the storage inside automobiles increased the leakage, but still was below the required MCLs .
The results revealed that minor leakage of Sb from PET bottles was due to plastic surface pollution at some stages of manufacturing process; while any major leakage was due to the changes in the bottle’s storage conditions. The effect of various storage conditions on the leakage of Sb in the remaining 15 samples were not considerable and/or far below the recommended MCLs in all samples. Conversely, in this study, an increase in Al concentration was observed.
According to Shotyk et al.  the comparison between the natural aggregates of Sb in the underground waters versus the PET bottled waters (same water before and after bottling) indicated Sb leakage from these bottles. It was established that Sb content of the bottled was 30 times higher than the water in the glass container . Keresztes et al.  studied ten different brands of pure and sparkling waters. The study demonstrated that the content of Sb in the sampled bottles was 0.03-0.1 ppt, which increased at room temperature, and in darkness. The study also revealed that light and temperature exposures could raise the concentration levels of Sb .
A study performed by Guler et al.  demonstrated that the levels of Sb in the various samples were higher than the Turkish legislative limits; 24% of natural spring water samples (24 out of 100), 28.6% of natural mineral water samples (2 out of 7) and 54.4% of drinking water samples (6 out of 11). The present study, analyzed Ba concentration at the initial stage of the study in 4 samples, as illustrated in Table 2, the results were higher than USEPA recommended MCL level .
The concentrations of Sb’s in 132 brands from 28 countries were studied by Shotyk et al. . Two of the brands had higher values than the MCLs of Japan (2 μg/l) which was mainly due to the use of Sb2O3 as the catalyst in the PET process. In 14 brands of bottled waters in Canada, Sb content during a 6 month storage period at room temperature increased approximately 19%, while the 48 brands of 11 European countries demonstrated an increase of 90% under the same condition. The analysis of the underground spring water contained 1.7 ± 0.4 ng/L Sb, following 6 month period of storage, the Canadian bottles Sb levels rose to 26.6 ± 2.3 ng/L, while the German bottled water demonstrated 28.1 ± 3.8 ng/L .
In a research conducted by Baba et al. , the Co content levels were 7-11 ppb in sampled bottles, and the Sb levels reported were lower than 1 ppb, which were below the detection limit. However, it should be mentioned that to date, WHO, EPA and Turkish standards have defined no standard for Co levels. Moreover, in the present study, the concentration of Co levels, in all samples were below the limit of detection (LOD) .