Aquasil

Free clopidogrel base, CCA, clopidogrel AM, and diltiazem (i.s.) Column Aquasil Ci8 column Human plasma (100 mm x 3 mm) Detector LC-MS/MS operated in electrospray ionization positive mode SRM monitoring Unchanged clopidogrel m/z 322 -> 212 Carboxyl metabolite m/z 308 -> 198 Active metabolite m/z 356 -> 212 Diltiazem 415 —> 178 Mobile phase gradient of ACN/ 0.1% formic acid... 

Column Keystone Aquasil 0810x2.1 mm, 5 pm, guard cartridge... 

A backup generic LC method is used for compounds failed by method 1 using the conditions as follows Column Keystone Aquasil Cl8 50 x 2.1 mm, 5 pm, column... 

A second set of test compounds, along with the original fo markers, was then put together and a further set of experiments conducted. The results from these experiments are presented in Table 8.2. The main requirement for success was to maximise the number of compounds with k greater than 1 (i.e. the compound was retained at least twice as well as something unretained). The Daisopak column achieved this for seven out of the ten compounds tested, the Aquasil and Platinum EPS achieved it with six compounds and the Alkyl HB with five compounds. 

Biological activity was determined by the rice lamina inclination assay. HPLC support and mobile phase A, Cjg silica and 45% acetonitrile B, Cjg silica and 45% acetonitrile C, silica (Aquasil) and chloroform-methanol (95 5, 1% water). Abbreviations CS, castasterone BL, brassinolide. 

Those possessing enhanced polar selectivity, as shown by a high hydrogenbonding capacity (i.e., a p values > 1), e.g.. Platinum CjglS EPS, Synergi Polar RP, Zorbax SB AQ, and Aquasil phases (column nos. 75, 105, 134, and 5, respectively) - group A. 

Group D Moderate surface coverage/hydrophobicity, shape selectivity, and hydrogen-bonding, and low ion-exchange capacity, as exemplified by phases of moderate retentivity and silanol activity, e.g., Nucleosil Cjg, Aquasil Cjg, Platinum Cjg, and pBondapak Cjg (column nos. 64, 5, 74, and 111, respectively). 

---