Chemistry Reference
In-Depth Information
TABLE 5.9
McCloskey et al. (1996) and Newman and McCloskey (1996) QSARs for Predicting Cation Toxicity Using Standard
Reduction-Oxidation Potential or a Combination of Standard Reduction-Oxidation Potential, Atomic Number, and Ionization
Potential Differential or Pearson and Mawby Softness Parameter
Reference
Test Substance(s)
QSARs
r
2
MSE
AIC
n
McCloskey et al. (1996)
Ag
+
, Ba
2+
, Ca
2+
, Cd
2+
, Co
2+
, Cr
3+
, Cs
+
, Cu
2+
,
Fe
3+
, Hg
2+
, K
+
, La
3+
, Li
+
, Mg
2+
, Mn
2+
, Na
+
,
Ni
2+
, Pb
2+
, Sr
2+
, Zn
2+
Log EC
50
= 0.14 + 1.62(ΔE
0
)
Log EC
50
= 0.95 − 0.19(AN/ΔIP) + 1.73(ΔE
0
)
Log EC
50
= 1.30 − 2.03(log AN/ΔIP) + 1.64(ΔE
0
)
Log EC
50
= −3.25 + 39.95(σ
p
)
0.57
0.65
0.65
0.73
1.696
1.571
1.569
1.349
82.06
78.50
78.44
71.04
20
20
20
20
Newman and McCloskey (1996)
Ca
2+
, Cd
2+
, Cu
2+
, Hg
2+
, Mg
2+
, Mn
2+
, Ni
2+
,
Pb
2+
, Zn
2+
Log EC
50
= −1.42 + 2.10(ΔE
0
)
Log EC
50
= 4.79 − 1.04(AN/ΔIP) + 0.83(ΔE
0
)
Log EC
50
= 7.03 − 11.99(log AN/ΔIP) + 0.78(ΔE
0
)
Log EC
50
= 12.87 − 110.9(σ
p
)
0.15
0.52
0.49
0.60
5.206
4.214
4.338
3.554
71.83
60.77
61.78
56.84
9
9
9
9
EC
50
is the 50% decrease in bioluminescence of
Vibrio fischeri
caused by the total metal ion (unspeciated) after 15-min exposure.
AN is the atomic number.
ΔIP is the difference of the ionization potential in volts between its oxidation number (OX) and the next lower one (OX - 1).
ΔE
0
is the standard reduction-oxidation potential, also known as the absolute value of the electrochemical potential in volts between the ion with the oxidation number OX
and its first stable, reduced form.
σ
p
is the Pearson and Mawby softness parameter.
MSE is mean square error and AIC is Akaike's Information Criterion. QSARs with the smallest AIC are likely to have the most information regardless of the number of
independent variables.
