pH of the mobile phase was adjusted to 2.7 using 50% orthophosphoric acid
. The mobile phase was degassed and filtered through 0.45um millipore filters.
* Group II: prophylaxis paste (Sultan; Topex, NJ, USA)+37% orthophosphoric acid
(Condicionador Dental Gel; Dentsply, Rio de Janeiro, Brazil)+primer and adhesive (Transbond XT; 3M Unitek, Monrovia, USA);
Celluloid bands were adapted on both surfaces, followed by etching the enamel for 30 s and the dentin for 15 s with 37% orthophosphoric acid
(Total-Etch 3M Scotchbond Universal Etchant, 3M ESPE, GmbH Dental Products, Neuss, Germany).
We also evaluated isocratic elution with mobile phases constituted of water/acetonitrile or methanol; three different acidifying agents were tested (trichloroacetic acid, trifluoroacetic acid, and orthophosphoric acid
), flows ranging from 0.5 to 1.2 mL [min.sup.-1] and wavelength of 254 and 280 nm.
The gradient involves two mobile phases consisting of 10 g/ L solution of orthophosphoric acid
in water as solvent A and 10 g/L solution of orthophosphoric acid
in acetonitrile as solvent B.
Potassium chloride, Disodium hydrogen orthophosphate, Potassium dihydrogen orthophosphate, Hydrogen peroxide, Certrimide, Agar, CTAB, Glucose and Glycerol, Sodium nitrite and Orthophosphoric acid
, Sodium carbonate, Sodium bicarbonate, Isopropanol, Phenol, Chloroform, Ethylene diamine tetra-acetic acid, Boric acid, Glacial acetic acid, Isoamyl alcohol, Sodium hydroxide, Sodium acetate, Sodium dihydrogen phosphate, Magnesium sulphate were purchased from Qualigens & Merck, India respectively.
(Shenyang, China); and orthophosphoric acid
was purchased from Zhiao Chemical Reagents Research Institute (Anshan, China).
After isolation of the fractured tooth, acid etching of the fractured fragment surfaces and maxillary right central incisor surfaces was done with 37% orthophosphoric acid
(3M ESPE) for 15 seconds.
The supernatant (2 mL) was mixed with two drops of orthophosphoric acid
and 4 mL of the Salkowski reagent (50 mL, 35% of perchloric acid, 1mL 0.5M Fe[Cl.sub.3] solution).
Anionic counterions (e.g., hexanesulphonic acid, orthophosphoric acid
, and trifluoroacetic acid) interact with the basic residues (i.e., arginine, lysine, and histidine) of a protein and with the protonated N-terminus.
We have used acidic medium by adding concentrated orthophosphoric acid
to get the good crosslinking action of glutaraldehyde.