1-benzhydrylpiperazine

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-04-06 to 2016-04-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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))

Deviations:

no

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))

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: European Commission (EC), Technical Guidance Document on Risk Assessment Part III, Chapter 4.3: “Use of (Quantitative) Structure Activity Relationships ((Q)SARs) - Soil and Sediment Sorption”, 2003.

GLP compliance:

yes (incl. QA statement)

Remarks:

See study report

Type of method:

HPLC estimation method

Media:

other: HPLC column

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: M15BB1451
- Expiration date of the lot/batch: 2021-01-30
- Purity test date: 2015-05-21 (certificate of analysis release date)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature
- Stability under test conditions: no data

Radiolabelling:

no

Test temperature:

- Column temperature ± 35°C

Details on study design: HPLC method:

EQUIPMENT
- Analytical conditions:
* Instrument: Acquity UPLC system (Waters, Milford, MA, USA)
* Detector: Acquity UPLC PDA detector (Waters)
* Column: Acquity UPLC HSS Cyano, 100 mm x 2.1 mm i.d., dp = 1.8 µm (Waters)
* Column temperature: 35°C +/- 1°C
* Mobile phase: pH 7 55/45 (v/v) methanol/ phosphate buffer at pH 7, 0.01M
* Flow: 0.4 mL/min
* Injection volume: 5 µL
* UV detection: 210 nm

MOBILE PHASES
-Preparation of the solutions:
* Solution of the unretained compound: A 5.0 g/l stock solution of formamide (99.2%, [75-12-7], Alfa Aesar, Karlsruhe, Germany) in methanol was used. The stock solution was diluted to obtain an end solution of 55/45 (v/v) methanol/phosphate buffer at pH 7, 0.01M. The formamide blank solution was 55/45 (v/v) methanol/phosphate buffer at pH 7, 0.01M.
* Reference substance solutions: Stock solutions of the reference substances at concentrations of approximately 1 g/l in methanol were used. The stock solutions were diluted to obtain an end solution of 55/45 (v/v) methanol/phosphate buffer at pH 7, 0.01M. The blank solution for the mixture of reference substances was 55/45 (v/v) methanol/phosphate buffer at pH 7, 0.01M.
* Test solution: A 1000 mg/l stock solution of the test item was prepared in methanol. The stock solution was diluted to obtain an end solution of 55/45 (v/v) methanol/phosphate buffer at pH 7, 0.01M. The final concentration of the test item solution was 10.0 mg/l. The test item blank solution was 55/45 (v/v) methanol/phosphate buffer at pH 7, 0.01M.

REFERENCE SUBSTANCES
- Identity: Acetanilide; Monuron; 2,5-Dichloroaniline; Naphthalene; Benzoic acid phenylester; Fenthion; Phenanthrene; 4,4’-DDT

REPETITIONS
- The reference substance and test item solutions were injected in duplicate. Blank solutions were analysed by single injection.

EVALUATION
- Calculation of capacity factors k': from retention time of reference items, the test item, and then on-sorbed chemical item
- Determination of the log Koc value: a correlation of log k' versus log Koc of the reference items is plotted using linear regression - the log k' value of the test item is then used to calculate its log Koc value

Key result

Type:

Koc

Value:

970 000 dimensionless

pH:

7

Key result

Type:

log Koc

Value:

5.99 dimensionless

pH:

7

Details on results (HPLC method):

- Retention times (tr,1 and tr,2) of reference substances used for calibration:
* Formamide (t0): tr1 = 0,673min; tr2= 0,674min
* Acetanilide: tr1 = 0,866min; tr2= 0,862min
* Monuron: tr1 = 1,052min; tr2= 1,045min
* 2,5-Dichloroaniline: tr1 = 1,184min; tr2= 1,174min
* Naphthalene: tr1 = 1,376min; tr2= 1,361min
* Benzoic acid phenylester: tr1 = 1,616min; tr2= 1,596min
* Fenthion: tr1 = 2,069min; tr2= 2,027min
* Phenanthrene: tr1 = 2,316min; tr2= 2,281min
* 4,4’-DDT: tr1 = 5,404min; tr2= 5,243min
* Test item: tr1 = 7,637min; tr2= 7,621min

- Details of fitted regression line (log k' vs. log Koc): log K' = 0.314 x log Koc - 0.864 (r = 0.98, n = 16).
- Average retention data for test substance: 7.629 min
- Koc test substance = 9.7 x 10^5

Statistics:

pKa values of the test item were calculated using the Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International San Francisco, CA, USA).

The following pKa values for acidic and basic groups in the molecular structure of the test item were calculated using the Perrin calculation method:

No acidic group

Basic groups:

1 -SUBST.-PIPERAZINE: pKa 8.85

RRRNH+: pKa 8.26

Based on these values, it was concluded that the test item is ionized for at least 10% within pH 5.5 to 7.5. Testing therefore should be performed with both the ionized and non-ionized form.

Testing with the non-ionized form at pH .10 is technically not possible. The cyanopropyl columns prescribed by the guidelines are not stable outside the pH range 2 to 8.

Testing with the ionized form was performed at pH 7. At this pH, >90% of the test item is in its ionised form.

Validity criteria fulfilled:

yes

Conclusions:

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of JNJ-130806-AAA (T000750). Based on pKa calculations, it was concluded that the test item is ionized for at least 10% within pH 5.5 to 7.5. Testing therefore should be performed with both the ionized and non-ionized form according to the guidelines. Testing with the non-ionized form at pH ≥10 is technically not possible. The cyanopropyl columns prescribed by the guidelines are not stable outside the pH range 2 to 8. Testing with the ionized form was performed at pH 7. At this pH, >90% of the test item is in its ionised form. The Koc and log Koc values of the test item at pH 7 were 970000 and 5.99 respectively using the HPLC estimation method according to OECD guideline 121. The results of the test can be considered reliable without restriction.

Description of key information

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of JNJ-130806-AAA (T000750).  Based on pKa calculations, it was concluded that the test item is ionized for at least 10% within  pH 5.5 to 7.5. Testing therefore should be performed with both the ionized and non-ionized form according to the guidelines. Testing with the non-ionized form at pH  ≥10 is technically not possible. The cyanopropyl columns prescribed by the guidelines are not stable outside the pH range 2 to 8.  Testing with the ionized form was performed at pH 7. At this pH, >90% of the test item is in its ionised form. The Koc and log Koc values of the test item at pH 7 were 970000 and 5.99 respectively.

Key value for chemical safety assessment

Koc at 20 °C:

97 000

Additional information

[LogKoc: 5.99]