Nano cellulose

Different chemical compounds, such as nano-cellulose (Sigma-Aldrich, Darmstadt, Germany), Tylose (Methyl hydroxyethyl cellulose) (Sigma-Aldrich, Darmstadt, Germany), dimethyl sulfoxide (Sigma-Aldrich, Darmstadt, Germany), as well as NaOH, KOH and NaClO (Loba Chemie Pvt. Ltd., laboratory reagents & fine chemicals, Mumbai, India), were used.

methanol for lab analysis, and acetonitrile gradient grade for LC were purchased from Merck KGaA (Darmstadt, Germany). Heroin standard, in powder form, in 99.8% purity. Morphine monohydrate (MM) 1.0 mg/mL calibrated standard solution in methanol, monoacetyl morphine (6MAM) 1.0 mg/mL calibrated standard solution in methanol and morphine-3-β-glucuronide (M3B) 1.0 mg/mL calibrated standard solution in methanol was obtained from Lipomed AG (Arlesheim, Switzerland). Aniline (C6H5NH2) was obtained from Sigma-Aldrich Chemie GmbH (Taufkirchen, Germany) and it was distilled under vacuum before using. Lithium perchlorate (LiClO4) was purchased from Sigma-Aldrich Produktions GmbH (Steinheim, Germany). Nanocellulose, hydroxylamine hydrochloride (NH2OH.HCl), and hydrogen tetrachloroaurate (HAuCl4) were obtained from Sigma-Aldrich Chemie GmbH (Taufkirchen, Germany). Polyethylene glycol (PEG) 400, methanol, silver nitrate (AgNO3), and sodium hydroxide (NaOH) were purchased from Merck KGaA (Darmstadt, Germany).