Cyperus scariosus, ext.

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

EEC A.4
OECD 104

GLP compliance:

no

Type of method:

gas saturation method

Specific details on test material used for the study:

Name: Cypriol (Cyperus Scariosus ext. oil)
Bath No. 20016011417
Purity 100 % Natural
Manufactured date November 2016
Retest Date October 2018

Key result

Temp.:

ca. 20 °C

Vapour pressure:

ca. 1.727 other: mPa

Method Validation

The analytical method for the determination of test item concentration was validated by establishing linearity, range, accuracy, precision, specificity, Limit of Detection (LOD) and Limit of Quantitation (LOQ).

The results of methodvalidationare presented in Table 1 and
Table 2.

The chromatograms of the detector linearity check are presented in  Figure 1 and Figure 2anda graph of detector linearity check is presented as Figure 3.

The chromatograms of method accuracy of method validation test are presented as Figure 4 and Figure 5. The chromatogram of specificity of methodvalidationtest is presented as Figure 6.

Detector linearity

A series of working standard solutions of concentration 5.247 to 53.000 µg/mL were analyzed in triplicate by HPLC. The detector response found linear in this concentration range with a correlation coefficient (r) of 0.99976 (Table 1).

Limit of Detection (LOD) for the Method

The minimum quantity of the standardof 0.318µg/mL, was detected by the HPLC with signal to noise ratio of 4.55, was considered as Limit of Detection (LOD) of equipment.

From the above equipment LOD, which was in µg/mL of solution, the % method LOD, i.e. µg of analyte in 100 µg of sorbent was calculated and was found to be 0.28%

Limit of Quantification (LOQ) of the Method

The lowest concentration of the reference standard of1.040µg/mLanalysed using the method being validated.Further, at this concentration the percent relative standard deviation (% RSD) of the peak area of three measurements was1.39 % which was less than the value of 10.72 % obtained using extended Horwitz equation. The signal to noise ratio of the analyte peak at this concentration was >10.

Accuracy, Precision and Specificity

Accuracy as mean per cent recovery of test item found to be94.71±0.27and91.27±0.57for low and high dose, respectively (Table 2). This considered acceptable as the obtained mean percent recovery within 80 to 120.

The precision of the method at low and high dose of test item found to be0.29and0.62respectively (Table 2). This considered acceptable as the obtained % rsd less than 5.60 and 3.96 for low dose and high dose, respectivelyobtainedasper % rsd < 2^{(1 – 0.5 log C)}× 0.67.

Specificity of the method considered acceptable since, the control sample (unfortified) did not show any interference at the retention time of the analyte.

System Suitability Test

System precision checked by calculating relative standard deviation (% RSD) from the peak area values and retention time of all replicate injections of a working standard solution and less than 2.0% in each case. Acetonitrile, injected at the end of system suitability test, did not show injection carryover

Vapour Pressure

The measured quantities of active ingredient content in samples are presented in Table 3.

The amount of active ingredient of the test item transported by the inert gas adsorbed in the first and second layer in all the tests. Thesecond layer of 120°C top and third layers of all the test temperatures did not contain any active ingredient. This showed that the adsorbent efficient in adsorbing the entire transported test item. The vapour pressure at different temperatures calculated. The results on correction of flow rate for pressure and temperature difference and volume of saturated gas and vapour pressure are presented in the Table 4, Table 5, Table 6 and Table 7.

Vapour Pressure at 120°C

The vapour pressure of the test item determined at 120.2°C for three different gas flow rates (5, 10, and 15 mL/min). The vapour pressure of test item 6.4172 × 10^-1, 5.5815 × 10^-1and 6.1466 × 10^-1Pa, at 5, 10 and 15 mL/min flow rates, respectively with a mean value of 6.0484 × 10^-1Pa (Table 8). The chromatogram of test sample of 120º C is presented as Figure 10 and Figure 18.

Vapour Pressure at 130°C

The vapour pressure of the test item determined at 130.1°C for three different gas flow rates (5, 10 and 15 mL/min). The vapour pressure of test item 9.4251 × 10^-1, 8.4889 × 10^-1and 9.0201× 10^-1Pa, at 5, 10 and 15 mL/min flow rates, respectively with a mean value of 8.9780 × 10^-1Pa (Table 8). The chromatogram of test sample of 130º C is presented as Figure 19 and Figure 27.

Vapour pressure at 140°C

The vapour pressure of the test item determined at 140.1°C for three different gas flow rates (5, 10 and 10 mL/min). The vapour pressure of test item 1.42174, 1.30661and 1.33634 Pa, at 5, 10 and 15 mL/min flow rates, respectively with a mean value of 1.35490 Pa (Table 8). The chromatogram of test sample of 140º C is presented as 28 and Figure 36.

Vapour Pressure curve

The vapour pressure curve plotted using inverse value of experimental temperature in K (1/T) on X- axis and log p (where
p = vapour pressure (Pa) determined at different temperatures) on
Y-axis Figure37).

Vapour Pressure at 20 and 25°C

The vapour pressure of the test item at 20 and 25°C extrapolated from the vapour pressure curve (Figure 37) using slope (--2919.1667) and intercept (7.1951). The calculated vapour pressure of test item at 20 and 25°C 1.7266 mPa and 2.5363 mPa, respectively (Table 8).

Conclusions:

The vapour pressure of test substance was observed 1.7266 mPa at 20°C

Executive summary:

The vapour pressure of test substance was observed 1.7266 mPa at 20°C

Description of key information

The vapour pressure of test substance was observed 1.7266 mPa at 20°C