A water soluble crosslinker N, N' methylenebisacrylamide (MBA) and initiator potassium persulphate
(KPS) were used in synthesis.
Gum Rosin (Gr) and potassium persulphate
(KPS) were purchased from HIMEDIA and SD-Fine Chemicals Pvt.
Following a polymerization step, ammonium persulphate
was added dropwise with constant stirring.
7mM ABTS solution that dissolved in 20 mM sodium acetate (PH 4.5) was reacted with 2.45 mM potassium persulphate
to generate [ABTS.sup.+] radical cation, and the mixture was kept in dark room temperature for 12-16 h before use.
Sodium citrate, citric acid, and potassium persulphate
(99%) were purchased from "Sigma" (Sigma-Aldrich, Steinheim, Germany).
The acetone (HPLC grade), hydrochloric acid (37%), potassium persulphate
(99%), 2,2,-Azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS, 98%), and orthophosphoric acid (85%) were purchased from Sigma-Aldrich GmbH (Buchs, Switzerland).
The ABTS was generated by reacting an ABTS aqueous solution (7 mM/L) with potassium persulphate
([K.sub.2][S.sub.2][O.sub.8]) (2.45 mM/L, final concentration) in the dark at room temperature for 16h and adjusting the absorbance at 734 nm to 0.700 with ethanol.
Some food additives reported to cause cheilitis such as potassium persulphate
in denture cleansers, castor oil in chewing gum and colophonium in dental floss (3-6).
(3.) Morgan, LB, "Transient Molecular Species Occurring in Persulphate
[ABTS.sup.*] was generated by the reaction between 7mM ABTS and 2.45 mM potassium persulphate
The stacking gel solution (125 mM Trishydrochloride (Tris-HCl) pH 6.8, 0.1% (w/v) SDS, 5% (w/v) acrylamide (acrylamide: bis-acrylamide ratio of 37.5: 1), 0.07% (w/v) ammonium persulphate
and 0.03% (v/v) N,N,N',N'-tetramethylethane-1,2-diamine (TEMED) was overlaid on the separating gel solution (373 mM Tris-HCl pH 8.8, 0.1% (w/v) SDS, 12% (w/v) acrylamide, 0.04% (w/v) ammonium persulphate
and 0.05% (v/v) TEMED).
Total nitrogen (TN) and total phosphorus (TP) concentrations were determined subsequently to the digestion with boric acid and potassium persulphate
, following the methodology described in APHA (2005) using the same HACH kits as those used for dissolved nutrients.