UHPLC columns exhibit very high numbers of theoretical plates, so good separation can be achieved even on short columns.

Retention of alkylbenzenes

Column size:	2.1 mmI.D. x 50 mm
Mobile phase:	Acetonitrile : Water = 60 : 40
Flow rate:	0.4 ml/min
Temperature:	40°C
Detection:	UV 254 nm
Sample:	1. Benzene (n=0) 2. Toluene (n=1) 3. Ethylbenzene (n=2) 4. Propylbenzene (n=3) 5. Butylbenzene (n=4) 6. Amylbenzene (n=5)

Separation of structural isomers of vitamin D

COSMOSIL 1.8C₁₈-MS-II has strong retention and selectivity for hydrophobic compounds, so it can separate these structural isomers of vitamin D. The C₁₈-MS-II series has particle sizes of 1.8, 2.5, 3, 5, and 15 µm available, so scaling up to preparative separation is a smooth process.

Column size:	2.1 mmI.D. x 50 mm
Mobile phase:	Methanol : Water = 90 : 10
Flow rate:	0.4 ml/min
Temperature:	40°C
Detection:	UV 265 nm
Sample:	This sample was prepared by mixing the below in a 1:3 ratio: 0.25 mg/mL vitamin D3 in methanol 0.25 mg/mL 7-DHC in methanol, exposed to 254 nm UV light for 30 min. Previtamin D3 Vitamin D3 Lumisterol 7-Dehydrocholesterol (7-DHC)

COSMOSIL 1.8C₁₈-MS-II and COSMOCORE 2.6C₁₈ were compared to a competitor UHPLC column. COSMOSIL 1.8C₁₈-MS-II, with its high retention for hydrophobic compounds, is able to separate compounds that the competitor column was not able to separate. COSMOCORE 2.6C₁₈ is similar in retention and selectivity to the competitor column, but ran with less than half the backpressure.

Drug analysis (NSAIDs)

COSMOSIL 1.8C₁₈-MS-II, with its high hydrophobicity and selectivity, was able to separate difficult compounds.

Column size:	2.1 mmI.D. x 50 mm
Mobile phase:	Methanol : 0.1%HCOOH aq.  = 60 : 40
Flow rate:	0.4 ml/min
Temperature:	40°C
Detection:	UV 260 nm
Sample:	1. Acetylsalicylic Acid 2. Loxoprofen 3. Ketoprofen 4. Naproxen 5. Phenylbutazone 6. Celecoxib 7. Diclofenac 8. Indometacin

Flavonoid analysis

Compared to isocratic elution, in this gradient elution, the differences in retention time between the columns was small, and elution order was the same. However, COSMOSIL 1.8C₁₈-MS-II and COSMOCORE 2.6C₁₈ were still able to separate compounds that were not separated on the competitor column.

Column size:	2.1 mmI.D. x 50 mm
Mobile phase:	A : 0.1% formic acid in water B : 0.1% formic acid in acetonitrile B conc. 10 → 70% 10 min. linear gradient
Flow rate:	0.4 ml/min
Temperature:	40°C
Detection:	UV 280 nm
Sample:	1. Acetylsalicylic Acid 2. Loxoprofen 3. Ketoprofen 4. Naproxen 5. Phenylbutazone 6. Celecoxib 7. Diclofenac 8. Indometacin (Inj. vol.: 1.0 µl)

UHPLC columns are routinely exposed to high pressures. To evaluate the durability of these columns, amitriptyline was injected 1,000 times into each column. Neither COSMOSIL 1.8C₁₈-MS-II nor COSMOCORE 2.6C₁₈ saw deterioration in retention time or peak shape (width at half height).

COSMOSIL 1.8C18-MS-II	COSMOCORE 2.6C18

Our UHPLC columns use the same connectors as Waters UPLC^® (UHPLC) columns. This is different from our conventional COSMOSIL columns, which use the conventional Waters HPLC-compatible connectors. Attempting to connect an unsuitable fitting may result in it becoming stuck in the column.

  COSMOSIL 1.8C18-MS-II Packed Column