nitrate and nitrite were extracted from the toothpaste using distilled water and separated from other water-soluble excipients by two rp-8 columns ( 250 mm x 4 mm i.d . ) using a mobile phase containing 0.2 % ( w/v ) sodium acetate and 2.5 % ( v/v ) glacial acetic acid in distilled water .
C0043047
water
C0790233
distilled water