The method is used for the GLC profile of all fragrances the suppliers have a GLC profile as a reference for the products that they supply. Gas Chromatography An Overview or Profile, The test method covers the use of Gas-Liquid Photographic analysis for the following Text test methods.
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The section in the test method
Gas Photographic Profile  =        A
Determine of Terpene Alcohols   =         B
Determine of Composition o-Phenylphenol   =  A
Determine of D-Phenothrin Tec 93% - Assay   =   A
Determine of GC Assay Permethrin 25/75 Â Â Â Â =Â Â Â A
Determine of Monoglyceride Content          =   Â
A
Determine of Assay Determination of Butoxyethanol =A
Determine of Isopropyl Alcoholic-Purity GLC= A
Determine of Distilled Fatty Acids - Composition GLC= C
Determine of Butoxypropanol – Purity= A
Determine of Methoxyisopropanol-GC Assay= A
Determine of Propylene Glycol - GC Assay =D
Determine of Methanol Content of Alcohol Denatured=
A
Determine of purity Benzene Content by GC =A
Determine of Det of solvents in Light Duty Cleaners
by GC= E
MSC2058 Checking Gas Chromatographic
equipment= F
REFERENCES
Suppliers Method for GLC profiles
for their fragrances together with reference profiles produced under the test method
conditions.
Health & Safety Sheet for the
fragrances.
Health & Safety Data Sheets
for chemical reagents used in this method.
Operation Manual for GLC.
Reference profiles are available
for raw materials that have been examined by R & C in the past and reside
with the laboratory that does the testing.
Definitions ofÂ
GLC Profile -Gas-Liquid Chromatographic profile (trace) obtained when using the column packing as described in the method by the supplier or if it is an internal method the packing specified with the appropriate carrier gas and detector. Details for calibrating the instrument are described in this method.
PrincipalÂ
The various constituents of a
mixture, when heated to a temperature at which they are volatile and then
passed through a column using an inert carrier gas, are absorbed and released in
the column packing at different rates depending on their chemical constitution.
By using a detector at the end of the column, the constituents are traced as a
series of peaks. By using reference materials as markers that have been passed
through the column previously under the same conditions of temperature and gas
flow the peaks are identified.
The trace for the raw material in
the form of a chart can then be compared with a reference trace to show that
the constituents are the same and are in the same proportions. By measuring the
area under the peaks, the proportion of any one constituent is approximately
the area under its peak divided by the total area under all the peaks. In practice, it may be necessary to use correction factors for some constituents when
accuracy is required.Â
The correction factors may be obtained by using reference standards and checking the analysis of a mixture of known compositions.
REFERENCES MATERIALS
Reference materials are used in
GLC to identify the positions of peaks and identify the size of the peak with concentration.
The material needs to be selected from a reliable source and have a guarantee of
its purity.
Butoxy propanol - used as a
marker.
Methoxy isopropanol - used as a
marker.
Ethanol 100%.
Capillary inlet evaluation sample (ref. HP 85004789).
ReagentsÂ
Precautions: Chemicals used for gas
chromatography need a much higher purity than for other analyses and must be suitable
for GLC
Nitrogen - Must be suitable for
Chromatography (High grade of purity).
Helium used as carrier gas purity
must be suitable for GLC analysis.
Helium used as carrier gas purity
must be suitable for GLC analysis.
Standard Solution: Weigh to the nearest 0.1 mg 4g of butoxy isopropanol (W1) and 4g methoxy isopropanol (W2) into
100 ml volumetric flask and makeup to the mark with distilled water.
Marker Solution: Weigh 4g ethanol
to the nearest 0.1 mg in a 100 ml volumetric flask and makeup to the mark with distilled
water.
Distilled water.
EQUIPMENT
General
Gas chromatography apparatus
fitted with a capillary column.
F.I.D. detector.
Capillary column (Packed as
specified by the supplier or method).
Injector.
Micro syringe for injection.
Determine Terpenes by gas Chromatography
Column: 2m x 4 mm ID glass column
packed with 5% Carbowax 20M on diatomite CLQ (100-120 mesh)
Oven: Column: 120°C.
Injection Port 200°C.
Detector: 250°C.
Carrier gas Nitrogen at 50 ml/min.
Detector Flame ionization.
Determine Propylene Glycol by gas Chromatography
FID detector.
1m x 4 mm column Packed with 5%
G16 on support S5.
Injection port temperature 240°C.
Detector temperature 250°C.
The column temperature is programmed at 5°C per minute from 120° to 200°.
Carrier Gas Helium.
Light Duty CleanersÂ
100ml volumetric flasks.
2 ml pipettes.
30 ml vials.
Capillary GC.
Column BP1.
Oven temperature 100°C.
Injector temperature 270°C.
Detector temperature 270°C.
Carrier gas Helium at 12 psi.
Balance weighing to nearest 0.1 mg.
2 ml Pipettes.
100 ml volumetric flasks.
INTERFERENCE
When comparing a raw material or
finished product against a reference profile produced in the past it is
essential to use the same column packing and the same conditions to make a
direct comparison. If this is not possible it will be necessary to run the
reference again using the column which is available. It is essential to use
pure reagents suitable for GLC.
Certain compounds such as those
containing chlorine will poison the detector so care should be taken not to run
halogen-containing compounds with the FID detector.
SAMPLING
The small quantities used for GLC analysis make it essential to prepare a sample that is representative of the whole unless it is planned to produce a sampling plan and analyze it to find the variation across the consignment. If sampling a finished product is essential to mix well before taking the sample.
Procedure ofÂ
Precautions: Read health & Safety
data sheets for all reagents and chemicals that you use in the analysis. Also, read
the health and safety data sheet for raw materials or finished products. Read
the Operations Manual for the GLC equipment and its ancillaries that you are
using and heed any warnings given.
General
Select the conditions, column
packing, and detector given in the relevant method and prepare the equipment accordingly.
Start the chromatogram.
Wait for the equipment to
stabilize.
Call up the test method.
Record the chromatogram.
Compare it with the reference
chromatogram.
Determine Terpene AlcoholsÂ
Inject 0.1μl of sample and allow
the chromatogram to run for twice the retention time of the major peak,
-terpineol
The early eluting peaks are terpenes which are followed by terpene alcohols. Estimate the percentage of terpene alcohols by calculating the areas of the peaks with a corrected relative retention time greater than 0.33 concerning -terpineol.
Using the conditions specified
in 7D above the approximate retention times for propylene glycol is 5.7
minutes, and for the three isomers of di propylene glycol, when present, are
8.2, 9.0, and 10.2 minutes, respectively.
Inject a suitable volume, typically
about 10 μl, of propylene glycol into a suitable gas chromatograph, and record
the chromatogram.
Light Duty Cleaners
Into a 30 ml vial pipette 2 ml
(6E.2) of standard solution and 2 ml of marker (6E.3). Inject 0.5 μl into the
GLC under the conditions listed above. Record the ratio of the ethanol peak
area to the methoxy isopropanol peak area (methoxy isopropanol STD ratio) and
of the ethanol peak area to the butoxy propanol peak area (Butoxy propanol STD
ratio).
Into a second 30 ml vial weigh 4
g sample W3 to the nearest 0.1 mg and add by pipette 2 ml of marker solution.
Inject 0.5 μl and record the peak ratios as before (Methoxy isopropanol
SAMPLE ratio and Butoxy Propanol SAMPLE ratio)
CALCULATION OF RESULTS
General Compare the chromatogram
obtained with the standard reference chromatogram.
As a general guide, there must be
no more than 10% peak deviation on the peak areas obtained. For assays of purity, the limits will be stated in the specification. If the conditions are not met
clean the injector and detector before repeating the operation.
Terpenes
Terpene alcohols, % w/w = T x
100/A
Where T = Summation of the peak
areas with corrected relative retention times than 0.33 with respect to-terpineol.
A = summation of the peaks.
Distilled Fatty Acids
COMPOSITION GLC C16 C18 saturated (total).
C18 Unsaturated.
Propylene Glycol
% C3H6O2 = Area of C3H6O2 Peak x 100/Total area of all peaks except air and water Light Duty Cleaners
                     Sample ratio x W1
x 2
% Methoxy iso Propanol = ---------------------------------
                    Standard ratio x W3
                  Sample Ratio x W2 x 2
% Butoxy Propanol =
---------------------------------------
                                   Standard
ratio x W3
ACCURACY & PRECISION OF GC
A chromatogram showing the profile gives a means of showing whether all peaks are present or whether contaminants or constituents are missing. For this purpose, the chromatogram is normally better than ± 10%. If it is used for determining the purity and the appropriate calibration graphs are run and correction factors applied then an accuracy of ± 1% is possible.
13. The report shall state whether the GLC profile is satisfactory or unsatisfactory for checking fragrances.Â
For purity, it will state the % of each ingredient to 1 decimal place and show whether this
complies with the specification. For limit, tests report the value and state
whether it complies with the specification. Gas chromatography profile to
conform to suppliers' specifications as carried out by suppliers' method.