Cyclohexanethiol

Additional physico-chemical information

Administrative data

Endpoint:

other: Analytical validation method

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2012-10-10 to 2012-11-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted in accordance with an acceptable scientific method and in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Sanco 3029

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexanethiol

EC Number:

216-378-7

EC Name:

Cyclohexanethiol

Cas Number:

1569-69-3

Molecular formula:

C6H12S

IUPAC Name:

cyclohexanethiol

Constituent 2

Reference substance name:

Cyclohexylmercaptan

IUPAC Name:

Cyclohexylmercaptan

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): Cyclohexylmercaptan

- Substance type: monoconstituent substance

- Physical state: clear colourless liquid

- Analytical purity: 99.97%

- Purity test date: 2012-05-31

- Lot/batch No.: 2012-05-1765

- Expiration date of the lot/batch: 2014-06-07

- Stability under test conditions: Stable

- Storage condition of test material: At room temperature in the dark under nitrogen

Results and discussion

Results:

The analytical method is succesfully validated

Any other information on results incl. tables

Specificity

Chromatograms of a test substance solution and the blank accuracy sample are shown in Figure 1and Figure 2 (attached), respectively.

 

The chromatogram of the blank accuracy sample showed no peak at the retention time of the test substance. Since no interferences were detected, the specificity requirements were met and the analytical method was found to be specific for the test substance.

Linearity

The calibration line was constructed using all data points. Figure 3 (attached) illustrates the calibration curve and Table 1 shows the statistical parameters.There was a linear relationship between response and test substance concentration in the range of 3.98 – 598 mg/l (in end solution). Since the coefficient of correlation (r) was > 0.99 and the back calculated accuracies of the data points were in the range 85-115% the calibration line was accepted.

 

Table 1       Statistical parameters of the calibration curve

Slope	1.61´10^3
Intercept	2.75´10^2
Weighting factor	1/concentration^2
r	0.9998

Accuracy and repeatability

The results of the accuracy samples are given in Table 2. Since the mean accuracy at each concentration level fell in the criterion 70-110% and the coefficient of variation was ≤ 20% the analytical method was accepted for the analysis of the test substance in water in the target concentration range of 10 - 1000 mg/l.

Table 2       Accuracy samples

Target concentration [mg/l]	Nominal concentration [mg/l]	Analysed concentration [mg/l]	Accuracy [%]	Mean accuracy [%]	Coefficient of variation [%]
10	9.97	9.48	95	98	7.3
	9.97	9.90	99
	9.97	9.29	93
	9.97	11.0	110
	9.97	9.32	94
1000	997	987	99	100	0.55
	997	1002	100
	997	992	100
	997	996	100
	997	992	100

Limit of quantification

The limit of quantification (LOQ) was assessed as 10 mg/l in water.

Stability of analytical system and end solutions

The results of the stability of the analytical system and end solutions are given in Table 3. Since the coefficient of variation at both concentration levels was ≤ 20% the analytical system and end solutions were stable over at least a 3.65 hour time interval.

 

Table 3       Stability of the analytical system and end solutions

Nominal concentration [mg/l]	Elapsed time [hours]	Coefficient of variation [%]
3.98	4.50	2.5 (n=3)
15.0	4.36	2.0 (n=3)
598	3.65	1.3 (n=3)

Stability of stock solutions

The coefficient of variation on the response factors of the calibration solutions prepared with fresh and stored stock solutions was 0.31%. Since the value was ≤ 10% the stock solutions were stable when stored at room temperature for at least 1 day.

Conclusion

The analytical method was validated for the following parameters:

 

Specificity	specific
Linearity	r = 0.9998
Accuracy	98 and 100%
Repeatability	7.3 and 0.55%
Limit of quantification	10 mg/l
Stability analytical system and end solutions	Stable (3.65 hours)
Stability stock solutions	Stable (1 day)

Applicant's summary and conclusion

Conclusions:

The validation of the analytical method was succesfully performed.