Journal of Analytical Methods in Chemistry

Research Article

Characterization of Urban Particulate Matter by Diffusive Gradients in Thin Film Technique

Table 2

Characteristics of traffic-related metals in the PM listed according to source categories.


Origin/element	Total content (µg·g⁻¹)	Soluble fraction (%)	K_d (g·mL⁻¹)	DGT-measured mobile metal fraction (%)	Change of the DGT-measured resupply rate (%)
	(n = 3)	(n = 5)	(n = 10)	(n = 3)	(n = 5)
			Mean ± SD

Disk brake
Cu	625 ± 12	9.9 ± 0.5	0.079 ± 0.004	13.4 ± 2.4	14.3 ± 0.2
Sb	105 ± 16	32.8 ± 1.2	0.263 ± 0.010	1.8 ± 0.2	4.4 ± 1.7
Car body
Cd	10.1 ± 0.2	38.3 ± 2.5	0.306 ± 0.021	9.0 ± 1.8	18.7 ± 5.8
Co	30.6 ± 0.8	4.4 ± 0.2	0.035 ± 0.002	31.0 ± 3.3	56.9 ± 18.2
Ni	146 ± 4	4.3 ± 0.2	0.034 ± 0.002	22.6 ± 2,6	27.5 ± 2.8
Pb	411 ± 8	2.3 ± 0.2	0.019 ± 0.002	5.7 ± 1.2	10.3 ± 0.1
Power fuel
Mo	53.9 ± 0.4	7.0 ± 0.3	0.056 ± 0.002	5.8 ± 0.5	12.1 ± 2.7
V	30.4 ± 0.7	2.3 ± 0.1	0.018 ± 0.001	17.4 ± 2.1	23.6 ± 7.2
Catalytic converter^a
Pd	0.186 ± 0.004	8.8 ± 0.1	0.0700 ± 0.0004	26.0 ± 8.2	7.7 ± 0.9
Pt	0.016 ± 0.002	0.22 ± 0.02	0.0017 ± 0.0001	<20	n.d.^b
Rh	0.034 ± 0.001	2.3 ± 0.1	0.0184 ± 0.0006	53.9 ± 3.8	19.2 ± 3.6

Note. Solubility is represented by the water-soluble fraction (n = 5) of the total metal content after 1-day extraction (r = 1.25 mL·g⁻¹), K_d is the average (n = 10) distribution coefficient for aqueous extraction, the mobile metal fraction is the percentage of the C_DGT-measured concentration from the overall metal concentration in the aqueous phase for the lowest demand of the probe ( = 3.33 mm, 8 h, n = 3) applied in the DGT experiment, and change of DGT-measured resupply rate is the percentage decrease of the metal flux per day within one-day short-term experiment ( = 1.73 mm, n = 5). n: number of replicates in evaluation of data from series of experiments; ^alimits of detection (LOD) of 11 ng·L⁻¹ Pd, 0.14 ng·L⁻¹ Pt, and 0.05 ng·L⁻¹ Rh for determination of these metals in aqueous media (supernatant, digest) and 0.56 ng·Pd, 0.002 ng·Pt, and 0.001 ng·Rh in DGT resin gel disks were achieved, respectively; ^bn.d.: not determined.