Page 23 - Application Notebook - Solution for Food Development

Application AD-0124Ph
News

Table 2: GC analytical conditions using Carbowax 20M Analyte Conc., ppm Analyte Conc., ppm
Packed column (6.6% Carbowax 20M 80/120 Carbopack
B, 2.60 mm I.D. x 2 m L) 1. Acetaldehyde 21 9. N-butyl acetate 12
13
2. Acetone
10. Iso-butanol
11
3. Ethyl acetate 15 11. Isoamyl acetate 17
o
Injection Temp. 175 C 4. Acetal 11 12. N-butanol 11
13a. Active amyl alcohol
-
5. Methanol
12
o
o
o
80 C (0.5 min), 4 C/min ~150 C, 6.. Isopropanol 13. Isoamyl alcohol 11
Column Temp. o o 7. N-propyl acetate 11 14. 1-Pentanol 16
10 C/min ~190 C (3 min) 8. N-propanol 10 15. Furfural 14
Injection Mode Direct
Carrier Gas N 2
Column Flow 14 mL/min
Injection Volume 1.0 µL
Detector 200 C, FID
o
Analyte Conc., ppm
1. Acetaldehyde 8
2. Acetone 8
3. Ethyl acetate 31
4. Acetal 8
5. Methanol 16
6. Isopropanol 36
7. N-propyl acetate 8
8. N-propanol 31 Figure 2: Alcohol congeners on CP-Wax 57 CB column
9. N-butyl acetate 16
10. Iso-butanol 8
11. Isoamyl acetate 18 Table 4: GC analytical conditions using Supelcowax 10
12. N-butanol 75
13a. Active amyl alcohol - capillary column
13. Isoamyl alcohol 8
o
14. 1-Pentanol 8 Injection Temp. 200 C
15. Furfural 16
o
o
o
45 C (5 min), 5 C/min ~65 C,
Column Temp. o o
10 C/min ~200 C (0.5 min)
Injection Mode Split, 1:5
Carrier Gas He
Linear Velocity 31 cm/sec
Figure 1: GC-FID result of 15 alcohol congeners on 6.6% Injection Volume 1 µL
Carbowax 20M 80/120 Carbopack B, 2.60 mm I.D. x 2 m L. Detector 260 C, FID
o
Analyte Conc, ppm
Comparison of four capillary columns
1. Acetaldehyde 4
2. Acetone 4
Supelcowax 10 and CP-Wax 57 CB columns are both made 3. Ethyl acetate 4
4. Acetal -
of 100% chemically bonded polyethylene glycol making 5. Methanol 4
these columns highly polar. The compounds tested showed 6. Isopropanol
7. N-propyl acetate 5
similar elution patterns for both columns (Figures 2 and 3) 8.N-propanol 4
9. N-butyl acetate 3
under the optimized conditions (Tables 3 and 4). In 10. Isobutanol 6
11. Isoamyl acetate 3
particular, the peak of methanol exhibited a characteristic 12. N-butanol 3
broad shape. The smaller internal diameter of CP-Wax 57 13. Isoamyl alcohol 4
13a. Active amyl alcohol -
CB resulted in full baseline separation of acetal from ethyl 14. N-pentanol 5
15. Furfural 5
acetate and active amyl alcohol from isoamyl alcohol
(Figure 2). While, the higher loading capacity of the wide
bore Supelcowax 10 column enabled better separation of
propyl acetate from ethanol (Figure 3).
Figure 3: Alcohol congeners on Supelcowax 10 column
Table 3: GC Analytical Conditions using CP-Wax 57CB
capillary column The SPB-20 capillary column, on the other hand, can be
classified as an intermediate polarity column. Figure 4
o
Injection Temp. 200 C shows the separation profile of this column. Its stationary
o
o
50 C (10 min), 5 C/min ~140 C, phase is made of bonded poly(20% diphenyl / 80%
o
Column Temp. o o
10 C/min ~190 C (3 min) dimethylsiloxane). The high phenyl content of the column
Injection Mode Split, 1:10 produced a different elution order when compared to
Carrier Gas He polyethylene glycol-based columns, which makes it
Linear Velocity 25 cm/sec suitable for confirmation analysis. One drawback of this
Injection Volume 1 µL column is the partially overlapping of two important
o
Detector 210 C, FID congeners, acetaldehyde and methanol.