slower, when compared to cationic and neutral compounds due to electrostatic
repulsion between root surface and anionic substances. However, looking at data
from the hydroponic experiment of Tai and co-workers [105] (Table 3, Fig. 5a), high
BCF ratios of SAs, ranging from 9.1 to 26.0, were quantified in two wetland plant
species (Indian shot (Canna indica) and yellow iris (Iris pseudacorus)) in a 7-day
trial. In this work, authors suggested that plants take up SAs via active processes.
However, the high BCF values might be related to the plant lipid content, since it is
considered as the main storage site for hydrophobic organic contaminants, as
hypothesized by the same group. To support this hypothesis, a positive correlation
between the obtained BCF and the respective log D OW , for several nutrient media
and soil articles (cited in Tables 3 and 4), was calculated (0.29 and 0.42, accordingly
( p > 0.05)). Nonetheless, for a specific antibiotic (tetracycline), the results were the
opposite (i.e. TF > BCF), meaning that this compound is rather translocated to the
aerial parts than being stored in roots [104], which can be explained by its hydrophilic behaviour (log D OW À5.44).
As observed for SAs, high average BCF > TF values for triclosan, diclofenac and
gemfibrozil were registered in hydroponic experiments (see Table 3). Several studies
focused on the antibacterial pharmaceutical triclosan, but only in some of them, high
average BCFs were obtained. It can be highlighted that highest BCFs were
Table 5 Chemical properties of cationic pharmaceuticals, as well as the average BCFs and TFs
calculated per compound in hydroponic studies
Compounds
log K OW
pH
pKa
log D OW
BCF
TF
Authors
Average values
Antibiotic
Clarithromycin
3.16
na
1.00
À1.98
9.91
0.04
[137]
Lincomycin
0.20
5.80
1.00
À4.84
0.33
0.08
[20]
Trimethoprim
0.91
5.80
0.88
0.09
2.45
0.23
[20, 97, 110, 112]
Anticonvulsant
Lamotrigine
2.57
6.05
0.65
2.49
7.86
0.12
[138]
Antidiabetic
Metformin
À2.64
6.00
1.01
À2.56
32.14
0.02
[65]
Beta-blocker
Atenolol
0.16
7.80
0.98
À2.23
0.21
2.79
[11, 109, 131]
Propranolol
3.48
na
1.00
0.15
0.92
0.22
[116]
Lipid regulator
Gemfibrozil
4.77
5.30
0.81
3.56
–
0.06
[114]
Psychotropic drug
Amitriptyline
4.92
7.00
1.00
3.60
29.85
1.11
[117]
Clomipramine
5.19
na
1.00
2.35
0.18
0.62
[139]
Diazepam
2.82
na
0.01
4.73
3.21
0.45
[109, 110]
Fluoxetine
4.05
7.00
1.00
1.05
13.96
1.03
[110, 117]
Sertraline
1.37
na
1.00
2.27
0.43
0.12
[139]
Trazodone
3.21
na
0.10
3.97
0.09
2.89
[139]
Symbols: na, means not available; À not possible to calculate
124
Y. Bigott et al.
repulsion between root surface and anionic substances. However, looking at data
from the hydroponic experiment of Tai and co-workers [105] (Table 3, Fig. 5a), high
BCF ratios of SAs, ranging from 9.1 to 26.0, were quantified in two wetland plant
species (Indian shot (Canna indica) and yellow iris (Iris pseudacorus)) in a 7-day
trial. In this work, authors suggested that plants take up SAs via active processes.
However, the high BCF values might be related to the plant lipid content, since it is
considered as the main storage site for hydrophobic organic contaminants, as
hypothesized by the same group. To support this hypothesis, a positive correlation
between the obtained BCF and the respective log D OW , for several nutrient media
and soil articles (cited in Tables 3 and 4), was calculated (0.29 and 0.42, accordingly
( p > 0.05)). Nonetheless, for a specific antibiotic (tetracycline), the results were the
opposite (i.e. TF > BCF), meaning that this compound is rather translocated to the
aerial parts than being stored in roots [104], which can be explained by its hydrophilic behaviour (log D OW À5.44).
As observed for SAs, high average BCF > TF values for triclosan, diclofenac and
gemfibrozil were registered in hydroponic experiments (see Table 3). Several studies
focused on the antibacterial pharmaceutical triclosan, but only in some of them, high
average BCFs were obtained. It can be highlighted that highest BCFs were
Table 5 Chemical properties of cationic pharmaceuticals, as well as the average BCFs and TFs
calculated per compound in hydroponic studies
Compounds
log K OW
pH
pKa
log D OW
BCF
TF
Authors
Average values
Antibiotic
Clarithromycin
3.16
na
1.00
À1.98
9.91
0.04
[137]
Lincomycin
0.20
5.80
1.00
À4.84
0.33
0.08
[20]
Trimethoprim
0.91
5.80
0.88
0.09
2.45
0.23
[20, 97, 110, 112]
Anticonvulsant
Lamotrigine
2.57
6.05
0.65
2.49
7.86
0.12
[138]
Antidiabetic
Metformin
À2.64
6.00
1.01
À2.56
32.14
0.02
[65]
Beta-blocker
Atenolol
0.16
7.80
0.98
À2.23
0.21
2.79
[11, 109, 131]
Propranolol
3.48
na
1.00
0.15
0.92
0.22
[116]
Lipid regulator
Gemfibrozil
4.77
5.30
0.81
3.56
–
0.06
[114]
Psychotropic drug
Amitriptyline
4.92
7.00
1.00
3.60
29.85
1.11
[117]
Clomipramine
5.19
na
1.00
2.35
0.18
0.62
[139]
Diazepam
2.82
na
0.01
4.73
3.21
0.45
[109, 110]
Fluoxetine
4.05
7.00
1.00
1.05
13.96
1.03
[110, 117]
Sertraline
1.37
na
1.00
2.27
0.43
0.12
[139]
Trazodone
3.21
na
0.10
3.97
0.09
2.89
[139]
Symbols: na, means not available; À not possible to calculate
124
Y. Bigott et al.