Characteristics, Distribution, and Source Analysis of the Main Persistent Toxic Substances in Karst Groundwater at Jinan in North China

Table 1

Detection limits of the toxic heavy metals.

No.	Toxic heavy metals	Detection limits (mg/L)
1	Arsenic	0.005
2	Cadmium	0.0002
3	Hexavalent chromium	0.006
4	Lead	0.002
5	Mercury	0.0001