Boronic acid, B-(6-hydroxy-2-naphthalenyl)-

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 Oct 2013 to 13 Dec 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study was conducted according to an OECD Method and in accordance with GLP. The study material is well characterized.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

GLP compliance:

yes

Remarks:

OECD Principles on Good Laboratory Practice (revised 1997, ENV/MC/CHEM(98)17)

Type of method:

HPLC estimation method

Media:

soil

Test material

Test material information

Constituent 1

Reference substance name:

(6-hydroxynaphthalen-2-yl)boronic acid

EC Number:

687-349-8

Cas Number:

173194-95-1

Molecular formula:

C10H9BO3

IUPAC Name:

(6-hydroxynaphthalen-2-yl)boronic acid

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Physical state: off-white powder
- Storage condition of test material: Room temperature, in the dark (08 to 14 October 2013) Approximately 4 °C, in the dark (onwards).

Radiolabelling:

no

Study design

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Agilent Technologies 1100, incorporating autosampler and workstation
- Type, material and dimension of analytical column: Waters XSelect HSS Cyano 5µm (4.6 x 150 mm id)
- Detection system: UV, Dead time and reference standards: 210 nm. Sample: 230 nm

Column temperature: 30°C
Mobile phase: 55:45 (v/v) methanol:purified water
pH of mobile phase:5.98
Flow-rate: 1.0 mL/min
Injection volume: 10 µL

DETERMINATION OF DEAD TIME
- Method: The dead time was determined by measuring the retention time of formamide (purity
99.94%, 631 mg/L solution in 55:45 (v/v) methanol:purified water).


REFERENCE SUBSTANCES
Standard Purity* (%) Concentration (mg/L)
Acetanilide 99+ 100
Phenol 99.9 100
Atrazine 98.8 92.0
Isoproturon 99.9 98.0
Triadimenol 98.0 104
Linuron 99.9 94.0
Naphthalene 99.8 92.0
Endosulfan-diol 99.9 120
Fenthion 98.3 208
a-Endosulfan 99.6 100
Phenanthrene 97 94.0
Diclofop-methyl 99.2 92.0
DDT 98 94.0

Batch equilibrium or other method

Details on test conditions:

The calibration curve for the reference standards showed good first order correlation (R = 0.9651) and the retention times between duplicate injections for each solution were consistent, indicating that the HPLC method was valid for the estimation of the adsorption coefficient of the test item.

Based on dissociation constants estimates for the boronic acid and alcohol functional groups (9.2 ± 0.5 and 10.7 ± 0.8), the unionized form of the test item would dominate within the environmentally relevant pH range of 5.5 to 7.5. Therefore only a single evaluation, using an approximately neutral pH mobile phase, was performed.

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

Koc

Value:

< 17.8

Adsorption coefficient 2

Type:

log Koc

Value:

< 1.25

Results: HPLC method

Details on results (HPLC method):

The retention times of the dead time and the retention times, capacity factors (k') and log10 Koc
values for the reference standards are shown in the two following tables:

Dead Time Retention Time (min) Mean Retention Time
(min)
Injection 1 Injection 2
Formamide 1.890 1.890 1.890





Retention Time (min) Mean retention Capacity Log10 k' Log10 Koc
Factor (k')
Injection 1 Injection 2 time (min)
Acetanilide 2.619 2.619 2.619 0.386 -0.414 1.25
Phenol 2.498 2.493 2.495 0.320 -0.495 1.32
Atrazine 3.630 3.630 3.630 0.920 -3.61 x 10·2 1.81
Isoproturon 3.912 3.907 3.909 1.07 2.86 x 10-2 1.86
Triadimenol 5.321 5.326 5.323 1.82 0.259 2.40
Linuron 5.496 5.491 5.493 1.91 0.280 2.59
Naphthalene 4.708 4.708 4.708 1.49 0.173 2.75
Endosulfan-diol 6.910 6.900 6.905 2.65 0.424 3.02
Fenthion 8.260 8.256 8.258 3.37 0.527 3.31
u-Endosulfan 11.924 11.929 11.927 5.31 0.725 4.09
Phenanthrene 8.984 8.989 8.987 3.75 0.575 4.09
Diclofop-methyl 12.760 12.755 12.758 5.75 0.760 4.20
DDT 25.705 25.685 25.695 12.6 1.10 5.63

Any other information on results incl. tables

The retention times, capacity factors and log10 Koc values determined for the sample areshown in the following table:

Peak	Injection	Retention Time (min)	Capacity Factor (k')	Log10k'	Log10 Koc	Adsorption Coefficient (Koc)
Test item	1	2.877	0.522	-0.282	<1.25	<17.8
	2	2.877	0.522	-0.282	<1.25	<17.8

Mean Koc: <17.8

Mean log10 Koc: <1.25

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coeffcient of the components of the test material have been determined to be <17.8
log10 Koc <1.25