TABLE 2.

The concentration (mg/l) of the content in heavy metal in the samples.

ppm	Fe	V	Cr	Mn	Zn	Ba
MK	15–64	0.1–0.2	<0.1	0.1–2	0.1–0.2	0.1–0.7
FA	14–87	0.1–0.3	0.1–0.2	0.0–2	0.0–0.4	0.0–0.8
FA33K S.T.	29–35	0.1–0.2	<0.1	0.6–0.7	0.1–0.2	0.1–0.2
FA36Na S.T.	37–41	0.1–0.2	<0.1	0.8–0.9	0.1	0.3
FA67K S.T.	41–49	0.1–0.2	<0.1	1.3–1.4	0.2–0.3	0.3–0.4
FA67K 1,000	46–52	0.1–0.2	<0.1	1.4–1.7	0.2–0.3	0.3

The following elements were found in amounts lower than 0.1 ppm: Co, Ni, Cu, As, Se, Ag, Cd, Sb, Tl, Pb, and Be.

The lower limit of detection is 2 μg/l, while the upper limit of detection is 500 μg/l. When solutions were too concentrated, dilutions to 1:100 or 1: 1,000 were operated. Due to sample homogeneity and preparation procedure, the error affecting these results is around 30%.