Propanenitrile, 2,3,3,3-tetrafluoro-2-(trifluoromethyl)-

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 20, 2020 - October 07, 2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

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

GLP compliance:

no

Remarks:

GLP not required. Adsorption/desorption is not an ecotoxicology test and is not used to assign classifications.

Type of method:

HPLC estimation method

Media:

other:

Specific details on test material used for the study:

Name of test material (as cited in study report): MTDID 37480
- Physical state: White Solid
- Analytical purity: 97.7%
- Storage condition of test material: Ambient temperature
- Expiration date: 10/30/2021

Radiolabelling:

no

Test temperature:

25 °C

Details on study design: HPLC method:

EQUIPMENT
- Type: Agilent 1200 HPLC
- Type, material and dimension of analytical (guard) column: BDS Hypersil™ Cyano (4.6 mm X 150 mm), 5 µ (Thermo Scientific);
- Column temp: 25 °C
- Detection system: Mass Spectrometer- Sciex Triple Quadrapole MS model 5500;
- Mass Spectrometer Ions Monitored for unretained components (negative ions): Nitrate (m/z 62), Bromide (m/z 79).
- Mass Spectrometer Ions Monitored for refrence substances (positive ions): Aniline (m/z 94), 2-Nitrobenzamide (m/z 167), Atrazine (m/z 216), Methiocarb (m/z 226), Linuron (m/z 249), Fenthion (m/z 279), and Diclofop-methyl (m/z 358 ).
- Mass Spectrometer Ion for MTDID 37480 (negative ions): m/z 212

- Mobile phase:
Three different HPLC mobile phase conditions were used: condition 1 (55% methanol and 45% 0.1% formic acid in water, pH 4 ), condition 2 (55% methanol and 45% 2 mM ammonium acetate buffer, pH 7), and condition 3 (55% methanol and 45% water mobile phases; the recommended mobile phase mixture for OECD 121).
- Flow rate: 0.75 mL/min;
- Injection volume: 1 µl


DETERMINATION OF DEAD TIME T0 (retention time of the unretained component): The dead time for the HPLC column under each condition was determined by triplicate injection of an inorganic anion mixture containing nitrate and using the average retention time of the nitrate anion peak (m/z 62).

REFERENCE SUBSTANCES: Pesticide reference compounds used in this test were purchased from Sigma-Aldrich. The reference substances were selected from Table 3 of the OECD 121 with known log(Koc) values ranging between 1.45 and 4.20. The reference compounds were: 2-Nitrobenzamide, Atrazine, Aniline, Linuron, Methiocarb, Fenthion, and Diclofop-methyl. Stock solutions of the each reference substances were prepared in methanol, at concentrations range from 100 mg/L to 952 mg/L. A mixture of reference solution was prepared at nominal concentration of 0.1 mg/L in methanol by diluting the stock solution.

Preparation of test solution: The test substance MTDID 37480 was prepared as a 1020 mg/L stock in methanol. The stock solution was then diluted to 100 mg/L in methanol. The 100 mg/L solution was analyzed for retention time by HPLC with mass spectrometric detection (LC/MS).

REPETITIONS
- Number of determinations: 3

EVALUATION
- Calculation of capacity factors k': The capacity factor (k') is calculated from the retention of the substance concerned(Tr) and the unretained component (T0): k' = (Tr - T0)/T0
- Calculation of retention times:
- Determination of the log Koc value: Linear regression according to calibration curve of the log Koc of the reference substances as function of log k'
log koc = a log k' + b (a = slope derived from linear regression of reference compound; b = intercept derived from linear regression of reference compound)

Key result

Type:

log Koc

Value:

1.63 dimensionless

Temp.:

25 °C

Remarks on result:

other: pH 4 and 7

Key result

Type:

Koc

Value:

42.4 dimensionless

Temp.:

25 °C

Remarks on result:

other: pH 4 and 7

Details on results (HPLC method):

Details on results (HPLC method)
- Retention times of reference substances used for calibration: 2.78 - 4.17 minutes
- Details of fitted regression line (log Koc vs. log k'):
At condition 1 (pH 4, 0.1% Formic Acid-Methanol): log Koc = 6.69 log k' + 3.14 (r2= 0.875. n=6);
At condition 2 (pH 7, Ammonium Acetate Buffer-Methanol): log Koc =7.12 log k' + 2.89 (r2= 0.885. n=6);
At condition 3 (pH 7, low ionic strength, Water-Methanol): log Koc = 8.43 log k'+ 1.68 (r2= 0.874. n=6);

- Graph of regression line attached, See Figure 1.
- Average retention data for test substance:
At condition 1 (pH 4, 0.1% Formic Acid-Methanol): 2.86 minutes;
At condition 2 (pH 7, Ammonium Acetate Buffer-Methanol): 2.85 minutes;
At condition 3 (pH 7-low ionic strength, Water-Methanol): 2.83 minutes

The adsorption properties of MTDID 37480 did not appear to be affected by the pH or ionic strength of mobile phase during this study and showed similar log(Koc) results of 1.63, 1.66 and 1.60 for pH 4, 7 and pH7-low ionic strength
conditions, respectively.

Table 1. Log Koc determination for MTDID 37480

Test condition	Average Retention Time (minutes)	Avg. Capacity Factor (k’)	log k’	Calibration equation	log Koc	Estimated Koc
Condition 1 (pH 4)	2.86	0.609	-0.216	Log Koc= 6.69 log(k’)+3.14	1.66	45.2
Condition 2 (pH 7)	2.85	0.667	-0.176	Log Koc= 7.12 log(k’)+2.89	1.63	42.7
Condition 3 (Water)	2.83	0.977	-0.0102	Log Koc= 8.43 log(k’)+1.68	1.60	39.4
Average Log Koc					1.63
Average Koc (±Std. Dev.)						42.4 (2.9)

 

Validity criteria fulfilled:

yes

Conclusions:

MTDID 37480 had an overall measured log Koc value of 1.63 and Koc value of 42.4 (± 2.9) by OECD 121 HPLC method.

Executive summary:

The log(Koc) of MTDID 37480 was determined by HPLC method following OECD 121.

Six pesticide with known log(Koc) values ranging between 1.45 and 4.20 were selected as reference substances. Three different HPLC mobile phase conditions (i.e pH 4, pH 7, and pH 7 low ionic strength) are used to evaluate the effect of pH and ionic strength on MTDID 37480 adsorption. Under each HPLC condition, the reference mixture and test substance were each injected three times. The dead time for the HPLC column under each condition was determined by triplicate injection of an inorganic anion mixture containing nitrate. The average retention time for nitrate and the pesticide references under each HPLC mobile phase condition was used for calculating a capacity factor (k’) and then calibration curve of log(k’) versus log(Koc). The equation of the linear fitted line was used to determine the log(Koc) of MTDID 37480 based on its average retention time.

Under the analytical conditions used, MTDID 37480 had an overall log Koc value of 1.63 and Koc value of 42.4 (±2.9). The adsorption properties of MTDID 37480 did not appear to be affected by the pH or ionic strength of mobile phase during this study.

This study was conducted according to guidelines. The reference substances are approved for use in the method but bear little or no structural similarity to the test substance. Therefore, this study is considered as reliable with restrictions.

 

Reference 2

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2020-05-21 to 2020-12-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)

GLP compliance:

yes

Type of method:

batch equilibrium method

Media:

soil

Specific details on test material used for the study:

Name of test material (as cited in study report): MTDID 37480
- Source and lot/batch number of test material: 3M N.B. # us278898.001-096
- Physical state: White Solid
- Analytical purity: 97.7%
- Storage condition of test material: Ambient temperature
- Expiration date: 10/30/2021

Analytical monitoring:

yes

Details on sampling:

A Tier I preliminary test was carried out to determine: 1) the stability of the test item in the test system and adsorption performance on test vessel surfaces; 2) to determine the appropriate soil-solution ratio for Tier II adsorption kinetic testing.
In the stability test, two soil types, Red soils (RS) and Black soil (BLS) were selected. 0.01mol/L CaCl2 solution was added to the soil at a ratio of 1:5 soil: solution and shaken for 16 hours at 210 rpm. After shaking, 5mL stock solution of test substance was added into 45mL supernatant to obtain the test solutions. Two replicates were prepared for each soil type. The concentrations of the test substance in two replicates test solutions were measured at 0h, 24h, 48h and 72h which were compared with 0h concentration to determine the stability.

In the soil/solution ratios test, five typical Chinese soil types: the red soil (RS), yellow brown soil (YBS), black soil (BLS), chestnut soil (CHS) and alpine meadow soil (AMS) were selected at soil/solution ratios of 1:1, 1:5 and 1:25 respectively. Two replicates were prepared for each soil type and each soil: solution ratio. After pre-equilibrium of soil with 0.01M CaCl2 for shaking at 210 rpm for 16 hours, the stock solution was added into the soil/solution system. The mixed solutions were shaken for an additional 48h at 210 rpm, followed by centrifugation at 2500 rpm for 5min. 1mL aqueous phase was added into a 20 ml headspace vial containing 9 ml deionized water for analysis of the test substance.

Matrix no.:

#1

Matrix type:

other: Red soils(RS)

% Clay:

13.5

% Org. carbon:

1.21

pH:

4.89

Matrix no.:

#2

Matrix type:

other: Yellow brown soils(YBS)

% Clay:

11.6

% Org. carbon:

1.99

pH:

6.41

Matrix no.:

#3

Matrix type:

other: Chestnut soils(CHS)

% Clay:

2.96

% Org. carbon:

1.61

pH:

6.89

Matrix no.:

#4

Matrix type:

other: Alpine meadow soils(AMS)

% Clay:

4.37

% Org. carbon:

3.34

pH:

7.62

Matrix no.:

#5

Matrix type:

other: Black soils (BLS)

% Clay:

2.33

% Org. carbon:

3.26

pH:

5.82

Details on matrix:

COLLECTION AND STORAGE
- Geographic location: Five Chinese soil type from Jiangxi (Red soil, RS); Shanghai (Yellow brown soils, YBS); Inner Mongolia (Chestnut soils, CHS), Qinghai (Alpine meadow soils, AMS), and Heilongjiang (BLACK soils, BLS).
- Storage conditions: at ambient temperature and dry condition.
- Storage length: 1 to 7 years
Soil preparation: The soils were air-dried at ambient temperature. Disaggregation was performed with minimal force. The soils were sieved to a particle size ≤2mm and homogenized carefully.

Key result

Type:

other: % adsorption

Value:

< 10 other: %

Remarks on result:

other:

Remarks:

For all soil types and soil:solution ratio of 1:1, 1:5, and 1:25, pH not measured, room temerature

Details on results (Batch equilibrium method):

PRELIMINARY TEST
- Weighed soil: 2, 10, and 20 gram
- Volume of CaCl2 solution: 45, 15, 18 mL
- Initial test substance concentration: 119 mg/L

In the stability test, the average concentrations of the control samples were within 99.6~105% of the nominal concentration(0h-72h), which indicated the test substance in 0.01 mol/L CaCl2 solution was stable during the test and no adsorption happened on the surface of the test vessels. Also, the concentrations of the test solution was maintained within 100%~114% of the nominal average concentration (0h-72h) in equilibrium water from RS and BLS, which indicated the test substance in equilibrium water from RS and BLS was stable during the test.
In the soil/solution ratios test, the red soil (RS), yellow brown soil (YBS), black soil (BLS), chestnut soil (CHS) and alpine meadow soil (AMS) were selected to carry out the soil/solution ratios test, at soil/solution ratios of 1:1, 1:5 and 1:25 in duplicate. The results of the soil/solution ratios test indicated that, even at the highest soil/solution ratio(1:1), the duplicate adsorption percentages of the test substance in red soil (RS) were 4.20% and 5.00%, in yellow brown soil (YBS) were - 4.20% and - 3.40%, in black soil (BLS) were - 0.800% and - 0.800%, in chestnut soil (CHS) were 6.70% and -1.70%, in alpine meadow soil (AMS) were 9.20% and - 1.70%, respectively. The adsorption percentage of the test substance in 5 soils was less than 10%, which showed that there was no obvious adsorption of the test substance on these types of soils. Therefore, no subsequent tests were carried out.

Table 1. Adsorption results

Soil #	Soil to solution ratio	Dry soil amount (g)	Volume of solution (mL)	Rep 1 Solution phase Conc.(mg/L)	Rep 2 Solution phase Conc.(mg/L)	Rep 1 Adsorption %	Rep 2 Adsorption %
1 (RS)	1:1	20	18	114	113	4.2	5.0
	1:5	10	15	116	111	2.5	6.7
	1:25	2	45	114	116	4.2	2.5
2 (YBS)	1:1	20	18	124	123	-4.2	-3.4
	1:5	10	15	124	116	-4.2	2.5
	1:25	2	45	120	112	-0.8	5.9
3 (CHS)	1:1	20	18	111	121	6.7	-1.7
	1:5	10	15	125	110	-5.0	7.6
	1:25	2	45	116	116	2.5	2.5
4 (AMS)	1:1	20	18	108	121	9.2	-1.7
	1:5	10	15	118	115	0.8	3.4
	1:25	2	45	118	116	0.8	2.5
5 (BLS)	1:1	20	18	120	120	-0.8	-0.8
	1:5	10	15	125	118	-5.0	0.8
	1:25	2	45	118	114	0.8	4.2

 

Conclusions:

The test substance had less than 10% adsorption in 5 types of Chinese soil tested, there were no obvious adsorptions of the test substance on these soils.

Executive summary:

The soil adsorption/desorption character of MTDID 37480 was determined in a Tier I preliminary adsorption test in accordance with OECD 106 “AdsorptionDesorption Using a Batch Equilibrium Method”.
The Tier I preliminary test was carried out to determine: 1) the stability of the test item in the test system and adsorption performance on test vessel surfaces; 2) to determine the appropriate soil-solution ratio. In the stability test, two soils (Red soils, RS) and Black soil, BLS) were pre-equilibrated with 0.01 mole/L CaCl2 at a ratio of 1:5 soil: solution for 16 hours. After pre-equilibration, supernatant was obtained. Stability test solutions were prepared by adding 5mL stock solution of test substance into 45mL of supernatant.  Two replicates were prepared for each soil type. The concentrations of the test substance in two replicates test solutions were measured at 0h, 24h, 48h and 72h.  The average concentrations of the control samples were within 99.6~105% of the nominal concentration(0h-72h), which indicated the test substance in 0.01 mol/L CaCl2 solution was stable during the test and no adsorption happened on the surface of the test vessels. Also, the concentrations of the test solution was maintained within 100%~114% of the nominal average concentration (0h-72h) in equilibrium water from RS and BLS, indicated the test substance in equilibrium water from RS and BLS was stable during the test.
In the soil/solution ratios test, five Chinese soil types: the red soil (RS), yellow brown soil (YBS), black soil (BLS), chestnut soil (CHS) and alpine meadow soil (AMS) were selected at soil/solution ratios of 1:1, 1:5 and 1:25  respectively. Two replicates were prepared for each soil type and each soil: solution ratio. After pre-equilibrium of soil with 0.01M CaCl2 shaken for 16 hours, the stock solution was added into the soil/solution system. The mixed solutions were shaken for an additional 48h, then centrifugated. An aliquot of aqueous phase was sampled and diluted with water and analyzed with GC/FID. The adsorption percentage of the test substance in 5 soils was less than 10%, which showed that there was no obvious adsorption of the test substance on these types of soils. Therefore, no subsequent tests were carried out.
This is a guideline study conducted under GLP compliance. Since it is a preliminary test, it is considered reliable with restriction and a supporting study.

Description of key information

C4 F-isonitrile forms heptafluoropropylamide (MTDID 37480) in solution. MTDID 37480 had an overall measured Koc value of 42.4 (± 2.9) by OECD 121 HPLC method.

Key value for chemical safety assessment

Koc at 20 °C:

42.4

Additional information

C4 F-isonitrile is a gas at ambient temperature. Once in solution, the dissolved C4 F-isonitrile hydrolyzed to form amide. Therefore, soil adsorption coefficient (Koc) of heptafluoropropylamide (MTDID 37480) was investigated.

 

The log Koc of MTDID 37480 was determined according to OECD 121 "Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using HPLC". Three different HPLC mobile phase conditions (i.e pH 4, pH 7, and pH 7 low ionic strength) were used to evaluate the effect of pH and ionic strength on MTDID 37480 adsorption. The adsorption properties of MTDID 37480 did not appear to be affected by the pH or ionic strength of mobile phase during this study. MTDID 37480 had an overall log Koc value of 1.63 and Koc value of 42.4 (±2.9) under the conditions of this study. This study was conducted according to OECD guidelines but not under GLP compliance. The reference substances are approved for use in the method but bear little or no structural similarity to the test substance. Therefore, this study is considered as reliable with restrictions and a key study.

A Tier I preliminary adsorption test for MTDID 37480 was conducted in five Chinese soils according to OECD 106 “Adsorption/Desorption Using a Batch Equilibrium Method” and under GLP compliance. The adsorption percentage of MTDID 37480 in 5 soils was less than 10%, which showed that there was no obvious adsorption of the test substance on these types of soils. The preliminary test is considered
reliable with restriction and a supporting study.