Evaluation of 5 Kinds of 2 μm and Sub 2 μm C18 Columns
Based on Separation Behavior
www.chromanik.co.jp

Norikazu Nagae, Tomoyasu Tsukamoto and Shun Kojima
ChromaNik Technologies Inc. Namiyoke, Minato-ku, Osaka Japan 552-0001*Corresponding author email: nagae@chromanik.co.jp

A column packed with 2.6 μm or 2.7 μm superficially porous particle has been widely used on HPLC and UHPLC, because it showed not only excellent column efficiency but also lower back pressure than sub-2 umcolumn. Recently 2.0 μm and less than 2.0 μm superficially porous C18 columns were developed and have been available. In this study, 3 kinds of 2.0 μm and 1.7 μm superficially porous C18s and one totally porous
hybrid C18, one totally porous monodisperse C18 were evaluated regarding efficiency, hydrogen bonding capacity, hydrophobicity, steric selectivity as well as peak shape of acidic, basic and metal chelating compounds.
Compared C18 columns were SunShell C18 2 μm, Ascentis Express C18 2 μm, Kinetex C18 1.7 μm, Acquity BEH C18 1.7 μm and Titan C18 1.9 μm. Furthermore, efficiency loss due to frictional heating which yielded
under high pressure and at high flow rate was observed. This efficiency loss was larger for a totally porous C18 than a superficially porous C18. Especially totally porous hybrid C18 showed the largest efficiency loss
because of the lowest thermal conductivity.

3SunShell C18

1Company S
Core Shell C18

321

4
3

24Company P
Core Shell C18

1Column: SunShell C18, 2 μm 100 x 2.1 mm
Company S Core Shell C18, 2 μm 100 x 2.1 mm
Company P Core Shell C18, 1.7 μm 100 x 2.1 mm
Company W C18, 1.7 μm 100 x 2.1 mm
Company S Monodisperse C18, 1.9 μm 100 x 2.1 mm
Mobile phase: CH3CN/H2O=60/40
Flow rate: 0.5 mL/min
Temperature: 40 ºC
Sample: 1 = Uracil, 2 = Ethylbenzoate, 3 = Acenaphthene, 4 =Butylbenzene

Acenaphthene

3241Company S
Monodisperse C18

3214

Pressure(MPa)

Theoreticalplate/pressure(MPa-1)

1.04

48.5

613

1.19

53.5

477

Theoreticalplate

Tailingfactor

SunShell C18

29,721Company SCore Shell C18

25,533Company W C18Company PCore Shell C1824,700

0.9753.8458

Company W C18

14,511

1.01

54.1269

Company SMonodisperse
C1826,592

1.05

43.9605

Retention time/min

Separation of standard samples
1SunShell C18

21Company S
Core Shell C18

2Company P
Core Shell C18

21 2Company W C18

31 234Company S
Monodisperse C18

113

Company S Monodisperse C18
1254Company P
Core Shell C18

1

N1=6,604
TF1=1.55

2

N1=8,116
TF1=1.40

Company W C18
1Company S Monodisperse C182

N1=7,538
TF1=2.16

321322 3Company P
Core Shell C18

Column dimension: 100 x 2.1 mm
Mobile phase: CH3OH/H2O=75/25
Flow rate: 0.2 mL/min
Temperature: 40 ºC
Sample: 1 = Uracil
2 = Caffeine
3 = Phenol
4 = Butylbenzene
5 = o-Terphenyl
6 = Amylbenzene
7 = Triphenylene
72

1434

342 3
1

1Retention time/min

23SunShell C18

N4=7,440
TF4=3.34

Company S
Core Shell C18

N4=10,157
TF4=3.04

Company P
Core Shell C18

32

12Company W C18

Company S
Monodisperse C18

43

N4=21,096
TF4=1.18

1123234

N4=6,778
TF4=3.584N4=7,059
TF4=4.39

Company W C18

N4=6,374

Company SMonodisperse C1814313

N4=9,371

4 TF4=4.72

Retention time/min

Hydrophobicity

Steric selectivity(Amylbenzene/Butylbenzene) (Triphenylene/o-Terphenyl)

SunShell C18

0.43

1.59

1.41

Company S Core Shell C18

0.37

1.59

1.38

Company P Core Shell C18

0.45

1.57

1.17

Company W C18

0.35

1.55

1.30

Company S Monodisperse C18

0.53

1.58

1.16

CH3ONHOH

CH3CH3NHCH3NCH3Column dimension: 100 x 2.1 mm
Mobile phase: CH3CN/10 mM ammonium acetate pH 6.8=40/60
Flow rate: 0.3 mL/min
Temperature: 40 ºC
Detection: UV@250 nm
Sample: 1 = Uracil
2 = Propranolol
3 = Nortriptyline
4 = Amitriptyline

Company S C18
Company P C18
Company W C18

2040

60

80

100120Time/h8060
SunShell C18

40

Company S C18
Company P C18

20

Company W C18001,000 2,000 3,000 4,000 5,000 6,000

Durable test condition
Column size: 50 x 2.1 mm
Mobile phase: CH3CN/1.0% TFA, pH1=10/90
Flow rate: 0.4 mL/min
Temperature: 80 ºC

Elution volume/mL
Durable test condition
Column size: 50 x 2.1 mm
Mobile phase: CH3OH/20mM Sodium
borate/10mM NaOH=30/21/49 (pH10)
Flow rate: 0.4 mL/min
Temperature: 50 ºC

Measurement condition
Column size: 50 x 2.1 mm
Mobile phase: CH3CN/H2O=60/40
Flow rate: 0.4 mL/min
Temperature: 40 ºC
Sample: 1 = Uracil
2 = Butylbenzene

Measurement condition
Column size: 50 x 2.1 mm
Mobile phase: CH3OH/H2O=70/30
Flow rate: 0.4 mL/min
Temperature: 40 ºC
Sample: 1 = Butylbenzene

3

Decreasing of theoretical plate due tofrictional heating effect
35000
Core shell silica particle
has enough highthermal conductivity tomake frictional heating
diffuse. Heatdistribution is madeuniform in the column.

25000
20000
15000
10000

SunShell C18
Totally porous monodisperse C18
Totally porous hybrid C18

Retention time/min

Column dimension: 100 x 2.1 mm
Mobile phase: CH3CN/20 mM Phosphate buffer pH 7.0=60/40
Flow rate: 0.3 mL/min
Temperature: 40 ºC
Detection: UV@250 nm
Sample: 1 = Uracil, 2 = Propranolol, 3 = Nortriptyline, 4 = Amitriptyline

SunShell C18

40100*Company S monodisperse C18 was not evaluated under pH10condition because its pH stability is listed to be 2 to 8 in their catalog .

N4=14,555
TF4=1.27

Retention time/min2▲030000
2▲6001▲Company S monodispers C18Column dimension: 100 x 2.1 mm
Mobile phase: CH3CN/0.1% H3PO4=2/98
Flow rate: 0.2 mL/min
Temperature: 40 ºC
Detection: UV@210nm
Sample: 1 = Formic acid
2 = Acetic acid
3 = Propionic Acid

1

N4=18,722
TF4=1.08

4 TF4=4.69

62

N4=21,053
TF4=1.08▲80

20

Retention time/min

Retention time/min

Column dimension: 100 x 2.1 mm
Mobile phase: CH3CN/20mM H3PO4=10/90Flow rate: 0.2 mL/min
Temperature: 40 ºC
Detection: UV@250nm
Sample: 1 = 8-Quinolinol (Oxine)
2 = Caffeine

4Retention time/min(Caffeine/Phenol)

Company S
Core Shell C18

3

25000

Hydrogen bonding

100SunShell C18

1

1

Stability under pH1 and 10 Conditions

Comparison of Amitriptyline (4) as a strong basic compound2

k6=11.5

N1=2,655
TF1=3.16

Company S
Core Shell C18

1Column dimension: 100 x 2.1 mm
Mobile phase: CH3OH/H2O=30/70
Flow rate: 0.2 mL/min
Temperature: 40 ºC
Detection: UV@250nm
Sample: 1 = Uracil
2 = Pyridine
3 = Phenol

1

k6=7.7722

N1=86
TF1=4.96

Retention time/min

k6=9.863

N1=7,695
TF1=1.43

SunShell C18

1

N1=1,052
TF1=3.83

Company W C18

2

12
1

N1=16
TF1=5.50

Company P
Core Shell C1826

k6=7.4N1=5,856
TF1=2.32

Company S
Core Shell C18

376532

1

754

3

16754

3
1

543

k6=10.7

N1=19,217
TF1=1.59

SunShell C18

24

Theoretical plate

32

Comparison of Formic acid (1)as an acidic compound

Relative plate of butylbenzene/%

Comparison of Oxine (1) as ametal chelating compound

Relative retention/%

Comparison of Pyridine (2) asa basic compound

Theoretical plate and tailing factor

00.1

0.2

0.3

0.4

0.5

Flow rate/mLmin-1Column: 100 x 2.1 mm
Mobile phase: H3CN/H2O=60/40
Temperature: 40 ºC
Sample: Acenaphthene

0.6

0.7

Regarding totally
porous hybrid silica
particle, ethylene chain
in the skeletal structureof silica leads thermal
conductivity to reduce.
Consequently, biased
heat distribution makes
plate number low.

Conclusion• SunShell C18 column provided highly
inert phases that deliver excellent
chromatographic performance foracidic, basic, neutral and metalchelating analytes.
• SunShell C18 column showed
excellent stability under both acidic
and basic pH conditions as well ascompany W C18.
• A core shell C18 like SunShell
showed much lower frictional
heating effect than a totally porous
C18 or totally porous hybrid C18.