Free fatty acid phase

The purity of the product was determined by the checkers by GLC analysis using the following column and conditions 3-nm by 1.8-m column, 5% free fatty acid phase (FFAP) on acid-washed chromosorb W (60-80 mesh) treated with dimethyldichlorosilane, 90 C (1 min) then 90 to 200 C (15°C per rain). The chromatogram showed a major peak for methyl 2-methyl-l-cyclohexene-l-carboxylate preceded by two minor peaks for methyl 1-cyclohexene-l-carboxylate and l-acetyl-2-methylcyclohexene. The areas of the two impurity peaks were 5-6% and 0.5-2% that of the major peak. The purity of the product seems to depend upon careful temperature control during the reaction. The total amount of the two impurities was 14-21% in runs conducted at about -15 to -20°C or at temperatures below -23°C. 

GC and GC-MS Analyses. The concentrated extracts were analyzed on an Intersmat IGC 120F gas chromatograph with an ICR IB integrator using an SGE FFAP quartz capillary column (free fatty acid phase, 50 m x 0.22 mm i.d.) injection temperature 250°C, oven temperature 60°C for 8 min, operating temperature 230°C (temperature gradient 2°C/min). 

A gas chromatograph of the Hewlett-Packard 5890 series with a HP 7673A injector and a flame ionisation detector can be used. A capillary free fatty acid phase (Hewlett-Packard FFAP 19091F-105) column (50 m x 0.20 mm x 0.33 pm) is cut into two equal 25-m lengths, which are used for the separation, provided that a capillary pre-column (J W Scientific Altech 93493) with a 50% phenyl silicone DB 17 coating (1.35 m of a 15 mx0.25 mmx0.25 pm column) is installed. 

FFAP (free fatty acid phase) terephthalic acid modified Carbowax 50/250 340 580 397 602 627 2545 509... 

When partially esterified with terephthalic acid or nitroterephthalic acid, it is known as WG 11 or FFAP (free fatty acid phase). 

Figure 3.4 Headspace analysis of volatile fatty acids from aqueous solution. Chromatographic conditions 15 m x 0.23 mm fused silica column coated with free fatty acid phase, 130°C (1 min), then increased by 6°Cmin to 200°C. Sample thermostatted at 120°C. Trace B is a blank. Peaks 1 = acetic acid 2 = propanoic acid 3 = 2-methyl propanoic acid 4 = butanoic acid 5 = 3-methyl butanoic acid 6 = pentanoic acid 7 = 4-methyl pentanoic acid 8 = hexanoic acid 9 = heptanoic acid 10 = octanoic acid 11 = nonanoic acid 12 = decanoic acid. Reproduced from Closta, W., Klemm, H., Pospisil, P. et al.. The HS-lOO, an innovative concept for automatic headspace sampling, Chromatography Newsletter, 11, 13-17, 1983.

Hydrocarbon grease Polyethylene glycol Diethylene glycol succinate 1,2,3-Tris(2-cyanoethoxy (propane Free fatty acid phase... 

It is occasionally advantageous to be able to subject fatty acids in the unesterified form to GC analysis. In this instance, acidic liquid phases such as DEGS containing 3 % phosphoric acid, FFAP ("free fatty acid phase"), Carbowax 20M -terephthalic acid or the structurally related phase, SP-1000 , are used (see Section F.8). 

Gas chromatograph, equipped with a thermal conductivity detector or equivalent. The column consists of a 1 m length of 1 mm i.d. stainless steel tubing packed with 15% m/m FFAP (free fatty acid phase) or 10% m/m SE-30 silicone) coated on 60-80 mesh Uniport B. Helium is used as a carrier gas. 

Free fatty-acid phase, a polar stationary phase for GC columns. 

FFAP Free Fatty Acid Phase (polar stationary phase for GC)... 

Free Fatty Acid Phase (PEG 20 M dinitrotereph-thalate ester) on Uniport B, 3 mm X 1 m... 

Free Fatty Acid Phase (PEG 20 M ester of nitro-terephthalic acid) on Uni-port B, 3 mm x 1 m Alkyl distribution 10% PEG 2000 on Embacel 60-AW, 2 mm x 1.5 m ethoxy distribution 2% Versamid 900 polyamide resin on Chromosorb G-AW DMCS, 4 mm x 35 cm 12% Carbowax 20M-TPA polyethylene glycol tereph-thalate on Chromosorb W-AW DMCS, 2.7 mm X 1.6 m... 

C ()-Ci8 alkyl amine ethoxylates determination of alkyl chain distribution Cleavage/derivatization with acetic anhydride/p-toluene-sulfonic acid 15% Free Fatty Acid Phase (poly(ethylene glycol) nitroterephthalate) on Uniport B, 3 mm x 1 m 235 - C TC 53... 

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