Environmental Sciences Europe

Table 3 Panel A: Half-lives (DT₅₀) and DT₉₀ values of QE, QA, 3-OH-QA, and 3-OH-CQO. Panel B: Half-lives (DT₅₀) and formation fractions of metabolites resulting from sequential fitting

From: Degradation and sorption of the herbicides 2,4-D and quizalofop-P-ethyl and their metabolites in soils from railway tracks

Panel A
	pH	C_org	T [°C]/	DT₅₀/DT₉₀ [days], best fit^a
	(CaCl₂)	[%]	M [%]	QE	QA	3-OH-QA	3-OH-CQO
Soils from railway tracks
EB	7.7	0.15	20/49	21/> 1000 FOMC	96/414 DFOP	37/122 SFO	335/> 1000 FOMC
MBS	7.6	0.31	20/54	0.22/1.4 DFOP	113/488 DFOP	35/116 SFO	24/> 1000 FOMC
MR	7.6	≈ 0.04	20/67	0.21/0.98 FOMC	>1000/> 1000 SFO	630/> 1000 SFO	445/> 1000 SFO
CS	7.5	< 0.06	20/55	0.69/68 FOMC	371/> 1000 SFO	189/628 SFO	474/> 1000 FOMC

				DT₅₀ [days], modeling endpoints^b
Geom. mean, 20 °C, pF 2		≈ 0.1		4.0	276	101	246
Agricultural soils [17]
Min–max	5.0–8.2^c	0.8–4.6	20–22/40–70	0.3–1.1	7–182	7–69	42–258
Geom. mean, 20 °C, pF 2		2.8/1.9/1.5/2.1^d		0.4	24	18	63

Panel B
	sequence of fitting	DT₅₀ [days] QE^e	Formation fraction [%]	DT₅₀ [days] QA^e	Formation fraction [%]	DT₅₀ [days] 3-OH-QA^e
EB	QE → QA → 3-OH-QA → sink	28 FOMC	100	92 SFO	0.5	180 SFO
MBS	QE → QA → 3-OH-QA → sink	0.20 DFOP	100	105 SFO	3.0	91 SFO
MR	QE → QA → sink	0.21 DFOP	98	968 SFO
CS	QE → QA → sink	1.1 FOMC	100	746 SFO

T: temperature, M: moisture in % of water holding capacity
^aSFO: single first-order kinetics, DFOP: double first-order in parallel model, FOMC: first-order multi-compartment model. χ² values < 10%
^bCalculated according to [26], for details see Additional file 1: Table S5 and Additional file 2: Kinetic fits
^cMeasured in H₂O
^dIn degradation studies with QE/QA/3-OH-QA/3-OH-CQO
^eBest fit. χ² values ≤ 12%, except for 3-OH-QA in MBS (16%)

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