Table 3.

Lability degrees (ξ) of metal complexes obtained in the Mediterranean Sea and in the Belgian coastal Zone (BCZ) (Gao et al., 2019).

Element	cT, M	Free metal	DGT no gel (g0)	DGT thin gel (g4)	DGT-classic (g8)	${\xi }_{\mathrm{\text{in}}}^{\text{g}0}$	${\xi }_{\mathrm{\text{org}}}^{\text{g}0}$	${\xi }_{\mathrm{\text{in}}}^{\text{g}4}$	${\xi }_{\mathrm{\text{org}}}^{\text{g}4}$	${\xi }_{\mathrm{\text{in}}}^{\text{g}8}$	${\xi }_{\mathrm{\text{org}}}^{\text{g}8}$
	nmol L−1	nmol L−1	nmol L−1	nmol L−1	nmol L−1
MEDITERRANEAN SEA
Cd	0.066	0.0029	0.049		0.062	0.694	–			0.89	–
Fe	5.54	5.3 × 10−13	0.47		–	–	0.152			–	–
Ni	4.9	0.49	2.95		3.18	0.88	–			0.96	–
Co	0.12	0.019	0.058		0.064	0.81	–			0.94	–
Cu	4.53	0.0044	0.41		0.98	0.70	0.14			0.89	0.36
BELGIAN COSTAL ZONE
Pb	0.473	0.0047	0.0458	0.0644	0.073	0.22	3.8 × 10−10	0.40	1.1 × 10−9	0.51	2.0 × 10−9
Fe	205	1.6 × 10−9	37.3	66.6	72.9	–	0.34	–	0.53	–	0.64
Ni	39.5	5.53	5.65	8.17	9.91	0.04	0.04	0.11	0.10	0.18	0.17
Cu	27.7	0.070	3.62	7.61	8.09	0.38	0.14	0.58	0.27	0.68	0.37
Zn	180	10.8	33.6	45.0	50.2	0.96	0.07	0.98	0.16	0.99	0.25

c_T,M is the total dissolved metal concentration; values for Co from Dulaquais et al. (2017) and for the other metals from Ebling and Landing (2015) in the case of the Mediterranean Sea and our data in the case of BCZ. Percentages of each pool (free, inorganic, and organic) are from Stockdale et al. (2011, 2015, 2016). “in” stands for inorganic and “org” for organic. Superscripts: g0 indicates no hydrogel layer, g4 0.4 mm and g8 0.8 mm hydrogel layer.