PKKK/300/UP/059 Screening of Antimicrobials in cosmetic products using GCMS

GCMS – QP 2010

Ultrasonic bath

Glass conical flasks with screw cap

Volumetric flask (20 mL, 10mL, 5 mL)

Nylon filter, 47 mm diameter, 0.45 µm pore size or equivalent

GC autosampler vial

Ethanol

Metronidazole, Sulfamethoxazole, Trimethoprim, Chloramphenicol, Griseofulvin and Clindamycin Reference Standard

Chromatographic Parameters

◼ Column : Rxi – 5Sil MS 30m x 0.25mm x 0.25µm

◼ Oven temperature:

.

Mode : Split

Injection volume : 1 μL

Split ratio : 10:1

Column flow : 1.0mL/min

Inlet temperature : 250°C

Interface temperature : 280°C

MS source temperature : 230°C

Gas : Helium

Test Method

Stock Solution 1 (0.2 mg/mL)

Stock Solution 2 (0.5 mg/mL)

Pipette 2.5 mL of Stock Solution 1 and 6.0 mL of Stock Solution 2. Make up to volume to 10 mL with ethanol to yield 50 ug/mL of Metronidazole, Trimethoprim, Griseofulvin & Clindamycin and 300 ug/mL of Chloramphenicol & Sulfamethoxazole.

Note:

Concentration of reference standard solution can be modified as needed, depending on the availability of the standards & response of the instrument

Sample Preparation

Note: Further dilution of sample can be done if the concentration of sample is too high.

Note: Only standard solution of the compound of interest is injected into the instrument during repeat test for failed samples.

Results

From the chromatogram of the sample, a compound is reported as detected (positive) should the retention time and mass spectrum match between the sample and reference standard with more than 80 % similarity. The principal ions for the compounds are:

If any compound is detected, the procedure is repeated by another analyst on another day. The individual reference standard of the suspected compound is prepared according to the procedure above for confirmation of the compound in sample.