Humic acid

YFiler Platinum Casework kit performance was evaluated in the presence of PCR inhibitors such as hematin, humic acid, and tannic acid^{9 (link),10 (link)}. Stock solutions of each inhibitor compound were prepared as follows: hematin (Sigma, St. Louis, MO) was dissolved in 0.1 N NaOH; humic acid (Alfa Aesar) and tannic acid (Fisher Scientific) were dissolved in molecular biology grade distilled water (Ambion). Test samples were prepared with a constant input of 1 ng of 007 DNA per reaction and increasing concentrations of each inhibitor: 200 and 400 µM hematin, 100 and 200 ng/µL of humic acid, or 100, and 300 ng/µL of tannic acid (all final concentrations in PCR). The Applied Biosystems YFiler Plus PCR Amplification Kit was used for comparison.

Humic acid, 4-chlorobenzoic acid (pCBA), and titanium dioxide (99.9% Anatase) with a nominal
particle size of 32 nm and surface area of 45 m² g^–1 were obtained from Alfa Aesar (Haverhill, MA). Hydrochloric
acid (HCl), sodium hydroxide (NaOH), magnesium sulfate (MgSO₄), aluminum sulfate (Al₂(SO₄)₃),
sodium chloride (NaCl), and calcium chloride (CaCl₂) were
all purchased from VWR (Radnor, PA). A Nanopure Infinity system (Thermo
Fisher Scientific, Inc., Waltham, MA) was used to produce ultrapure
water (>18.2 MΩ cm). HPLC solvents including acetonitrile
and
phosphoric acid were purchased from Alfa Aesar, and all of them were
of HPLC grade.

Venlafaxine hydrochloride (>= 97.5%) and tert-butanol (99.5%) were purchased from Thermo Fisher Scientific (Geel, Belgium). Sulfuric acid (95–97%, pro analysis) and hydrochloric acid (37%, pro analysis) were received from Bernd Kraft GmbH (Duisburg, Germany). Ammonia (approximately 25%) was acquired from Honeywell Specialty Chemicals Seelze GmbH (Seelze, Germany). Tert-Butanol (Acros Organics, Geel, Belgium) was used as a radical scavenger. For natural organic matter simulation, humic acid was purchased from Alfa Aesar (≥98%, Haverhill, MA, USA). Hydrogen peroxide was used as a 30% stabilized H₂O₂ solution (Carl Roth, Karlsruhe, Germany). Acetonitrile was obtained from Carl Roth (Karlsruhe, Germany). Formic acid (FA) was received from Fluka-Honeywell (Seelze, Germany).

Polyacrylic acid (PAA) (Acros Organics^TM, Fair Lawn, NJ, USA), 25 wt.% solution in water, and polyallylamine hydrochloride (PAH) (Alfa Aesar^TM Ward Hill, MA, USA), procured in solid powder form, were used to form the PE coatings. 1-ethyl-3-(3-dimethylamionopropyl) carbodiimide (EDAC) (Acros Organics^TM, Fair Lawn, NJ, USA) was used as a crosslinking catalyst in the coating process. Silver acetate (AgC₂H₃O₂) (99% pure analyte from Acros Organics^TM, Fair Lawn, NJ, USA) and sodium hydrogen phosphate (Na₂HPO₄) (American Chemical Society (ACS) certified) were used to form AgPNP in the coatings. humic acid (HA) sodium salt (50–60% as humic acid, Alfa Aesar, Ward Hill, MA, USA) was the model natural organic matter (NOM) [54 (link)] that was used in the fouling tests. The antimicrobial property of the membrane was probed using E. coli (ATCC 15597). Tryptic soy broth (TPB) and tryptic soy agar (TPA) (Becton & Dickinson, Sparks, Franklin Lakes, NJ, USA) were used to grow the bacterial cultures and as the plating medium, respectively.

Ethylene-vinyl acetate copolymer with 19% of vinyl acetate (VA) monomer (EVA Greenflex FF55, melt flow rate at 190 °C/2.16 kg of 0.7 g/10 min ISO 1133), supplied by Versalis. S.p.A (Mantova) was used as polymer matrix. Humic acid (sodium salt) was purchased by Alfa Aesar (in the form of about 200µm granules). The biochar (HHB), used as filler, was obtained by the pyrolysis of small hemp hurds provided by Assocanapa s.r.l. and was unsuitable for other applications.