PONA Analysis on AB-PONA Column
Naizhong Zou, Beijing Chromtech Institute, Beijing, China
Zack Ji, Abel Industries, Inc. Newark, DE USA
1. Introduction
Gasoline, either naphtha, cracked or reformulated, contains large number of hydrocarbons
including isomers. Because of complex compositions, the analysis of individual components is a
challenging technique. ASTM D 5374 and D5374-92 give methods of detailed hydrocarbon
analysis (DHA) for gasoline and other petrochemical applications. This specified DHA is done on
high resolution capillary column, a 100% poly(dimethylsiloxane) column. Because of its
specifically important role in DHA, this column is often called PONA column. Common PONA
columns are either 0.20mm x 50m x 0.5um or 0.25mm x 100m x 0.5um.
Various software and methods have been developed for such PONA and DHA applications. There
are two techniques for these applications. One is based on multi-dimensional GC, and other is
based on high resolution chromatography. Both techniques use retention times of individual
hydrocarbons to identify and quantify each composite separated. As the number of the composites
of a gasoline can be as many as 500, the peak identification becomes very difficult and is very
critical step for DHA. Often peak identification can be errant. Intensive labor effort is then taken
to manually correct errors in peak identification.
Among various softwares for ASTM D5134, the software called PONA developed by Beijing
Chromtech Institute uses an algorithm of retention index to identify peaks. Because retention
index is relatively insensitive to the variations from columns, instruments and methods, this
software is able to automatically and correctly identify each peak with great confidence. Even
though this algorithm improves accuracy of peak identification, it still requires minimum
variations in column dimension, column retention time, column efficiency and column selectivity.
This application note describes a FCC gasoline application on an AB-PONA column. This
AB-PONA column replicates the performances of HP-PONA column, an industrial fleet column,
including column selectivity, column dimension and retentions. Under the same instrumentation
condition, the software PONA produces the same result as the one obtained from an HP-PONA
column for this application.
2. Experimental
Column:
The column used is an AB-PONA column, 0.20mm x 50m x 0.5um, coated with AB-1
stationary phase, part number 9002-PONA, obtained from Abel Industries, Inc., Newark,
DE 19713, USA. The column temperature limits are -60C to 325/350C. Prior to each run,
column was conditioned at 280C for 4hr.
Abel Industries, Inc.
page 1 of 7
Instrumentation conditions:
Instrumentation conditions are listed in Table I.
Table I the instrumentation conditions
Gas Chromatography
Agilent 6890 GC with ALS
Raw date acquisition
HP-Chemstation
Inlet
250C, s/s, split flow 140ml/min
Carrier
Nitrogen
Column head pressure
99kpa varied
Detector
FID, 300C
Oven
35C 10min, 0.5C/min to 60C,
2C/min to 180C, 10+min
Sample
A FCC gasoline sample
Injection
1ul
Column retention time calibration
Constant pressure mode was used for carrier flow. Column head pressure was adjusted to
have n-Pentane retention time around 9.75+-0.1min as holdup time prior to sample
injection.
For a comparison, the analysis was repeated on an HP-PONA column at the same
instrumentation conditions.
3. Software
DHA and PONA analysis
PONA software from Beijing Chromtech Institute, Beijing, China was used in a PC with OS
Microsoft 95 or above. It uses the following formula (1) to calculate the retention index of all
individual peaks.
RIi = （（RTi-Rtref_Cn）/（Rtref_Cn+1-Rtref_Cn）+ Cn）*100
（1）
RIi： Retention index of composite i
RTi： Retention time of composite i
Cn ： Reference peak of carbon n
Cn+1： Reference peak of carbon n+1
Rtref_Cn ：Retention time of reference peak Cn
Rtref_Cn+1：Retention time of reference peak Cn+1
Abel Industries, Inc.
page 2 of 7
Retention time of reference peaks can be searched automatically based on empirical
database built-in the PONA software
Calculation of Octane Number:
Two octane values defined by RON and MON are calculated as
i=N
RON = Cr + Fr ∑ Ai Wi
i=1
i=N
MON = Cm + Fm ∑ Bi Wi
i=1
Cr :
Fr :
Cm :
Fm :
Ai :
Bi :
Wi :
N :
（2）
（3）
given constant, RON
given correlation factor, ROM
given constant, MON
given correlation factor, MON
correlation coefficient of ith hydrocarbon, RON, listed in calibration table
correlation coefficient of ith hydrocarbon, MON, listed in calibration table
weight percentage of ith , measured by DHA
total number of peaks measured by DHA
Calculation of Carbon/Hydrogen（C:H）ratio:
i=N
C:H = ∑ (C:H)i Wi
i=1
（4）
(C:H)i : Carbon/Hydrogen of ith hydrocarbon
Wi :
weight percentage of ith , measured by DHA
N :
total number of peaks measured by DHA
3.4 Calculation of Specific Gravity (D):
i=N
D = ∑ Di Wi
i=1
Di :
Wi :
N :
（5）
Specific Gravity of ith hydrocarbon
Weight percentage of ith , measured by DHA
Total number of peaks measured by DHA
3.5 Data Analysis：
Abel Industries, Inc.
page 3 of 7
Once the separation of each composite in a gasoline sample is completed, the raw data
of DHA was generated by HP Chemstation or similar data acquisition software. The raw
data includes peak retention time, area and/or area percentage. The file format of the raw
data file used in this PONA software is .D.
After completion of the chromatography run, the PONA reads the raw data file, and
automatically identify the reference peaks (as many as to 13) from assigned one of three
databases for three types of gasoline. Manual correction of the reference peaks is only as
needed for the first run. Once the reference peaks are correctly identified, the software
can automatically calculate all physically and chemically values described in 3.1 to 3.4.
The report file can be either printed or transferred for a customized report.
4. Result
Fig 1 shows the comparable chromatograms of a FCC gasoline sample on AB-PONA and
HP-PONA columns. It is clearly that the AB-PONA exhibits a small retention time difference
from the HP-PONA column, however, the peak elution order and relative peak height ratios
are essentially same. Even for this retention time difference, the PONA software is able to
identify all peaks in both chromatograms. The physical properties calculated are listed in table
II for the results from two PONA columns.
Table II Calculated physical properties
Column
AB-PONA
HP-PONA
No. of peaks identified
300
301
Calculated RON
87.26
87.15
Calculated MON
78.18
78.07
C:H
7.33
7.34
Specific density
0.8064
0.8062
All other calculated values are listed in the table III.
Table III PONA analysis report of a FCC gasoline sample
PONA Columns
AB
Compositions
Wt%
P (Normal Paraffin)
HP
AB
HP
Wt%
V%
V%
3.29
3.28
3.68
3.67
I (Iso Paraffin)
25.81
25.69
28.37
28.20
O (Olefin)
9.14
9.40
10.08
10.40
N (Naphtha)
15.74
15.72
16.20
16.19
A (Aromatic)
46.02
45.91
41.67
41.54
Abel Industries, Inc.
page 4 of 7
5. Conclusion
Based on the above results and same instrumentation conditions used, it can conclude that
both AB-PONA and HP-PONA are essential identical. AB-PONA column has produced
almost same result as HP-PONA has.
6. Order Guild
Table IV lists the suggested parts for PONA application.
Table IV Suggested parts for PONA analysis
Item
Description
P/N
1
PONA software
9001-PONA
2
AB-PONA
9002-PONA
3
Gasoline Reference Sample, 1ml
9003-PONA
7. Other applications of AB-PONA column
The other applications of AB-PONA column would be the separations of natural gas,
pesticides, and VOC.
Abel Industries, Inc.
page 5 of 7
30
20
40
40
42
44
46
47.333
48
50
52
54
56
Abel Industries, Inc.
58
90
38
58
39.838
40.085
39.734
39.973
90
39.281
pA
38
60.008
pA
39.382
18
59.645
38.748
39.054
20.053
19.099
19.308
19.523
18.300
18
59.932
56
58.650
36
58.998
59.266
36
18.697
17.774
19.274
19.468
19.693
18.871
18.327
18.479
50
58.930
59.269
59.538
17.576
18.141
15.810
15.896
16.055
16.165
16.300
16.508
16.818
17.032
17.171
14.885
14.958
14.529
13.267
13.394
13.516
12.521
12.688
12.788
60
38.651
38.953
16
38.299
37.890
37.424
36.893
50
38.383
37.991
37.506
36.948
15.575
15.668
15.826
15.937
16.075
16.287
16.533
16.605
16.824
16.963
60
58.043
57.196
57.426
56.727
36.335
14.275
14.634
14.711
16
58.318
57.477
57.677
56.979
54
56.297
34
36.415
35.213
35.507
34.545
34.845
14
56.049
55.639
55.264
35.282
35.576
34.602
34.905
33.586
33.998
12.989
13.114
13.243
12.226
12.398
12.500
14
55.900
34
55.514
52
55.014
54.092
54.374
32
54.777
33.623
32
34.045
12
54.317
54.611
53.397
32.872
12
53.620
50
32.913
31.786
32.121
32.260
9.232
10.047
10.314
10.628
10.832
40
53.046
30
52.824
30
32.152
32.296
31.802
30.442
31.065
10
52.405
51.984
30.443
40
52.628
48
51.219
28
31.071
10
52.191
51.004
28
50.265
8
50.630
30
9.977
10.297
10.504
8.874
8
50.846
49.546
49.175
7.721
30
50.466
49.735
40
42
44
46
FID1 A, (PONA 2006-12-08 10-37-35\PONA12082.D)
48.716
20
49.372
26
28.456
28.759
29.097
29.285
29.590
29.878
27.580
27.844
24.827
6
28.425
28.739
29.077
29.265
29.574
29.866
27.541
27.803
25.778
26.207
26.389
26.639
26.818
26.944
25.350
23.568
2
4
6
FID1 A, (PONA 2006-12-08 10-37-35\PONA12082.D)
48.900
47.141
24.753
20
22
24
26
FID1 A, (PONA 2006-12-08 10-37-35\PONA12082.D)
47.673
47.982
48.235
25.719
26.155
26.335
26.592
26.766
26.895
25.276
23.805
24.212
24.530
20
47.868
48.178
48.413
46.188
45.792
24
46.377
44.876
23.475
4
45.970
45.602
40
45.444
22
23.715
50
24.126
24.447
60
44.237
44.441
60
43.701
2
44.395
44.608
44.784
45.048
50
42.452
20
42.794
20.731
40
21.043
21.150
21.459
21.803
22.057
22.348
22.561
22.792
23.036
23.359
70
43.858
50
42.594
20
20.207
20.363
0
42.937
30
20.585
20.766
20.903
21.004
21.147
21.324
21.671
21.932
22.236
22.442
22.682
22.799
22.928
23.256
50
40.922
41.120
41.401
41.645
41.857
20
20.053
20.212
40
40.802
40.989
41.277
41.519
41.726
30
39.973
20
40.369
30
40.085
0
40.478
pA
FID1 A, (PONA 2006-12-01 13-54-09\PONA12011.D)
90
80
70
10
0
pA
min
90
80
70
10
0
min
FID1 A, (PONA 2006-12-01 13-54-09\PONA12011.D)
80
10
0
min
80
70
10
0
min
pA
FID1 A, (PONA 2006-12-01 13-54-09\PONA12011.D)
90
80
70
60
10
0
pA
min
90
80
70
60
10
0
min
page 6 of 7
50
40
30
20
100
102
104
106
108
110
112
114
116
Abel Industries, Inc.
96
116
118
118
99.288
99.429
99.688
99.961
98.056
98
98
119.719
119.975
120.134
97.850
96
98.408
98.713
98.887
99.274
99.410
99.685
99.950
98.402
98.688
98.899
97.841
96.437
96.603
96.770
97.167
97.384
98.028
78
119.670
119.915
117.372
97.190
97.407
93.979
94.290
94.722
95.050
76
118.364
118.519
118.696
118.906
119.048
119.357
117.570
117.812
96.453
96.615
96.785
95.333
95.529
95.862
96.045
93.191
93.466
93.758
78
80.057
79.081
79.393
78.291
76.700
76.891
77.158
77.326
77.628
77.923
75.030
75.240
75.500
75.736
75.996
73.868
74.207
74.526
74.680
72.436
72.708
72.927
73.246
71.806
72.049
70.552
65.833
76
118.320
118.438
118.659
118.997
114
117.523
117.764
112
117.337
94
116.235
116.582
116.811
117.016
94
116.541
92
94.765
95.086
94.023
94.333
92
95.377
95.543
95.888
96.081
93.214
93.339
93.518
93.801
74
116.967
113.840
72
114.613
114.737
115.027
115.316
115.657
115.876
114.100
114.257
91.927
69.744
66.056
74
115.596
115.831
116.173
112.856
92.240
92.585
70.881
69.957
70.277
69.443
67.473
67.817
68.131
68.359
68.576
68.827
66.777
66.988
66.350
72
114.578
114.840
114.994
115.239
113.802
110
113.289
91.999
90
92.281
92.621
90.740
90.975
91.148
91.344
91.509
90.545
87.078
70
113.241
113.370
113.642
90
111.626
111.905
112.245
112.437
112.589
90.802
91.024
91.209
91.417
91.559
90.621
89.990
90.211
89.444
89.628
89.076
88.256
88.535
87.301
87.486
87.707
87.900
64.818
65.327
70
112.212
112.411
112.545
112.814
88
90.067
90.292
89.524
89.686
88
110.185
110.352
110.661
110.795
110.978
111.136
109.367
109.574
109.704
89.144
88.343
88.596
87.170
68
111.571
111.850
108
110.146
110.317
110.643
110.778
110.937
111.070
100
102
104
106
FID1 A, (PONA 2006-12-08 10-37-35\PONA12082.D)
109.190
86
108.856
87.397
87.555
87.789
87.990
86.777
80
82
84
86
FID1 A, (PONA 2006-12-08 10-37-35\PONA12082.D)
108.256
108.428
107.430
85.962
84.954
66
109.172
107.654
107.859
107.038
84
86.331
86.674
85.258
85.486
64
86.048
85.064
40
108.241
108.414
90
107.431
90
85.353
85.583
63.699
70
109.344
109.534
109.674
80
63.982
64.313
90
68
114.065
114.210
60
62.601
60
62
64
66
FID1 A, (PONA 2006-12-08 10-37-35\PONA12082.D)
108.845
70
63.148
63.373
pA
107.616
107.846
60
83.603
61.339
61.073
69.531
79.922
80.097
78.910
79.249
78.142
77.456
77.775
76.541
76.740
77.004
75.308
75.579
75.821
74.860
74.040
74.361
73.694
72.237
72.535
72.746
73.046
71.597
71.831
70.653
70.982
69.743
70.059
69.225
68.583
65.823
63.452
67.605
67.910
68.139
67.252
66.540
66.743
66.114
65.057
64.569
64.057
62.897
63.126
62.336
61.662
61.952
70
106.232
106.382
106.641
70
61.932
62.225
70.342
65.598
90
106.220
106.368
106.607
106.772
107.012
82
104.929
60
83.826
84.114
84.221
84.436
84.679
82.490
62
105.504
105.813
80
104.550
90
83.328
60
83.714
70
82.765
80
83.924
84.197
84.535
84.773
pA
82.610
81.301
90
104.920
80
103.533
70
82.884
81.547
81.737
81.914
82.154
pA
83.125
83.427
81.430
50
105.446
105.568
105.797
20
81.669
81.860
82.050
82.273
60
104.555
30
60.008
50
103.701
103.891
104.177
104.317
80
103.542
20
59.932
60.269
60
103.879
104.161
104.307
30
101.781
40
101.426
50
102.065
102.270
102.459
102.636
50
101.791
20
101.437
40
80.654
60
102.067
102.252
102.467
102.616
102.723
103.001
30
79.922
80.097
20
80.780
30
80.057
80.229
20
100.615
100.809
100.967
101.213
40
101.211
40
99.950
100.164
50
99.961
100.181
30
100.630
100.799
100.949
pA
FID1 A, (PONA 2006-12-01 13-54-09\PONA12011.D)
80
10
0
min
80
10
0
min
FID1 A, (PONA 2006-12-01 13-54-09\PONA12011.D)
10
0
min
10
0
min
pA
FID1 A, (PONA 2006-12-01 13-54-09\PONA12011.D)
10
0
pA
min
10
0
min
Fig. 1, Chromatograms of a FCC gasoline sample on an AB-PONA column and an HP-PONA
column. Top, AB-PONA; bottom, HP-PONA. Instrumentation condition is shown in Table I.
page 7 of 7