ethyl N2-dodecanoyl-.sc.l.sc.-argininate hydrochloride

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption

Remarks:

adsorption

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From January 10, 2000 to February 16, 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Guideline study with GLP.

Qualifier:

according to guideline

Guideline:

other: OECD Draft Document TGP/94.75

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD draft document TG/Adsorpti/97.94 (July 1997)

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Test temperature:

Ambient 18.5ºC

Details on study design: HPLC method:

EQUIPMENT
- Autosampler: Model ISS200, Perkin Elmer
- Pump: Model 510, Waters Associates
- Detection system: Model Lambda Max 481, Waters Associates
- Column: Apex cyano, 5µm, 25 cmx4.6 mm i.d.

MOBILE PHASES
- Type: Methanol/water, 50/50 v/v
- Flow rate: 1.0 ml/min
- Solutes for dissolving test and reference substances: Methanol

DETERMINATION OF DEAD TIME
- Method: by means of homologous series

REFERENCE SUBSTANCES
- Identity: Thiourea, Monolinuron, Triadimenol, Triadimefon, Azinphos Methyl, Pyrazophos and Sulprofos.

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 81.229 µg
- Quantity of reference substances: thiourea (14.290 mg/l); monolinuron (102.34 mg/l); triadimenol (99.900 mg/l); triadimefon (142.44 mg/l); azinphos methyl (45.900 mg/l); pyrazophos (127.06 mg/l) and sulprofos (53.590 mg/l)

REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k': 6.449
- Calculation of retention times: 22.275 minutes
- Determination of the log Koc value: 1.76

Analytical monitoring:

yes

Key result

Type:

log Koc

Value:

1.76

Temp.:

18.5 °C

Remarks on result:

other: calculated: log koc= 0.52*log kow+1.02

Key result

Type:

Koc

Value:

58

Temp.:

18.5 °C

Details on results (HPLC method):

- Retention times of reference substances used for calibration: Thiourea (2.990); Monolinuron (5.260); Triadimenol (6.305); Triadimefon (6.945); Azinphos Methyl (8.020); Pyrazophos (12.030); Sulprofos (27.405);
- Details of fitted regression line (log k' vs. log Koc): Slope: 0.38234; Intercept: -0.85667; Correlation coefficient: 0.99071
- Average retention data for test substance: 22.275

Table 1. Experimental results of N^α-Lauroyl-L-arginine ethyl ester monohydrochloride (L.A.E):

Test	Retention time (min)	Mean retention time (min)	K	log k	log Koc	Koc
1	22.42	22.275	6.4495	0.80955	4.3583	22819
2	22.13

Conclusions:

The test substance would be expected to be mobile in soils.

Executive summary:

The soil adsorption coefficient was determined by the HPLC method as described in OECD Draft document TGP/94.75 (April 1994) and subsequently in OECD Draft document TG/Adosorpti/97.94 (July 1997). The soil adsorption coefficient obtained experimentally in this study is considered as very high when compared against the partition coefficient (shake flask method). It is therefore considered more appropriate to use a calculation method for this material. The recommended formula for a nonhydrophobic material is log koc= 0.52*log kow+1.02. Using the measured log kow value of 1.43 gives a log koc result of 1.76 and a soil adsorption coefficient of 58.0.

The soil adsorption coefficient of N^α-Lauroyl-L-arginine ethyl ester monohydrochloride (LAE) was calculated: Koc = 58.0 at 18.5 ºC. Therefore the test substance would be expected to be mobile in soils.

Description of key information

Key study: Test method according to OECD Draft document TGP/94.75 (April 1994) and OECD Draft document TG/Adsorption/97.75 (July 1997). The soil adsorption coefficient of Nα-Lauroyl-L-arginine ethyl ester monohydrochloride (L.A.E) was calculated: Koc = 58.0 at 18.5 ºC. Therefore the Nα-Lauroyl-L-arginine ethyl ester monohydrochloride (L.A.E) would be expected to be mobile in soils.t method according to OECD.

Key value for chemical safety assessment

Koc at 20 °C:

58

Additional information

- Key study 1:

The soil adsorption coefficient was determined by the HPLC method as described in OECD Draft document TGP/94.75 (April 1994) and subsequently in OECD Draft document TG/Adsorpti/97.94 (July 1997).The soil adsorption coefficient obtained experimentally in this study is considered as very high when compared against the partition coefficient (shake flask method). It is therefore considered more appropriate to use a calculation method for this material. The recommended formula for a nonhydrophobic material is log koc= 0.52*log kow+1.02. Using the measured log kow value of 1.43 gives a log koc result of 1.76 and a soil adsorption coefficient of 58.0. The soil adsorption coefficient of N^α-Lauroyl-L-arginine ethyl ester monohydrochloride (LAE) was calculated: Koc = 58.0 at 18.5 ºC. Therefore the test substance would be expected to be mobile in soils.