Nitric acid

All the standards used in the analyses fulfilled the Atomic Spectroscopy Standard purity level. For ICP analysis, a multielement standard solution VIII: Al, B, Ba, Be, Bi Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Se, Sr, Te, Tl, Zn obtained by Merck (Darmstadt, Germany) was used. Trace metals III: Ba, Ca, Mo, Na, K, Mg were purchased by Perkin Elmer Life and Analytical Sciences (Shelton, USA). Tin, antimony, silver, vanadium, silicon, and lanthanum standards for atomic absorption were obtained from Carlo Erba Reagenti SpA (Rodano, Italy). The acids used for the digestion of samples in the microwave oven and for diluting the standard solutions fulfilled the proanalysis purity level. Nitric acid 65% and hydrochloric acid ≥37% were obtained from Carlo Erba Reagenti SpA (Rodano, Italy) and Sigma‐Aldrich Chemie GmbH (Steinheim, Germany), respectively.

Barium (II) nitrate (99.95%), scandium (III) nitrate hydrate (99.9%), iron (III) nitrate nonahydrate (98+%), citric acid (99+%), tetraethylorthosilicate (99%), sodium hydroxide (98%), and hydrogen tetrachloroaurate (III) trihydrate (99+%) were purchased from Alfa Aesar, Lancashire, UK. Paraffin wax (mp ≥ 65 °C) was purchased from Aldrich, St. Louis, MO, USA, cetyltrimethylammonium bromide CTAB (>99%) was obtained from VWR Int. GmbH, Vienna, Austria, chloroform was purchased from Merck KGaA, Darmstadt, Germany, and 3-mercaptopropyltriethoxysilane (95%) was purchased from Gelest, Morrisville, PA, USA. Nitric acid (65%), ethanol (99.5%), sodium hydroxide, and ammonium hydroxide (25%) were purchased from Carlo Erba Reagents S.A.S, Milan, Italy. All the chemicals were used without any further purification.

Titanium foil (0.2 mm thick,
99.9% purity) was obtained from Ankuro Int. GmbH (Germany). Nitric
acid (HNO₃, 65%) was bought from Carlo Erba Reagents GmbH
(Germany). Hydrofluoric acid (HF, 48–51%) and furfuryl alcohol
(FFA, 99%) were purchased from Fisher Scientific. Ethylene glycol
(99%), ammonium fluoride (NH₄F, 99.8%), sodium borohydride
(NaBH₄, 97%), sodium chloride (NaCl, 99%), sodium sulfate
(Na₂SO₄, >99%), Ibuprofen (IBF, ≥98%),
coumarin, and sodium hypochlorite (NaOCl) were purchased from Alfa
Aesar (U.K.). Ammonium chloride (NH₄Cl, 98%) and 7-hydroxycoumarin
were obtained from Acros Organics. Ethylenediaminetetraacetic acid
(EDTA), sodium thiosulfate (Na₂S₂O₃), and tert-butyl alcohol (TBA) were purchased from
Sigma-Aldrich. A graphite block (99.9%) was purchased from Beijing
Great Wall Co., Ltd. (China). Deionized water was used in all of the
experiments.

Chemicals were purchased from the following providers and used without further purification. BIM synthesis: Indole (99+%, Aldrich, St. Louis, MO, USA); 4-Nitrobenzaldehyde (>99%, Aldrich); Dichloromethane (>99%, Aldrich); Acetone (>99.5%, Honeywell, Charlotte, NC, USA); Acetonitrile (>99.5%, puriss. p.a., ACS reagent, reag. Ph. Eur., Aldrich); Chloroform (99.8%, ACS, Alfa Aesar, Haverhill, MA, USA); Diethyl ether (RPE-For analysis-ACS, Carlo Erba Reagents, Cornaredo, Italy); Ethanol (96–97.2%, Honeywell); Ethyl Acetate (>99.7% Chromasolv, Sigma-Aldrich, St. Louis, MO, USA); 2-methyltetrahydrofuran (99%, Alfa Aesar); Toluene (>99.5% ACS Reagent, Sigma-Aldrich).
Aerogel catalyst synthesis: tetraethoxysilane ((Si(OC₂H₅)₄, Aldrich 98%, TEOS); Urea ((NH₂CONH₂), Sigma-Aldrich (99.0–100.5%); Absolute Ethanol (CH₃CH₂OH, Carlo Erba); Nitric Acid (HNO₃, Carlo Erba); Iron (III) nitrate nonahydrate (Fe(NO₃)₃·9H₂O, Sigma-Aldrich 98%); Manganese (II) nitrate hexahydrate Mn(NO₃)₂·6H₂O, Sigma-Aldrich, ≥98%); Nickel (II) nitrate hexahydrate Ni(NO₃)₂·6H₂O, Sigma-Aldrich, ≥97%).

Tetraethyl orthosilicate (TEOS, ≥ 99.0%), 2-amino-2-(hydroxymethyl)-1,3-propanediol (AHMPD, ≥ 99.9%), cetyltrimethylammonium tosylate (CTATos, ≥ 98.0%), ammonium nitrate (NH₄NO₃), ferric chlorid (99%) and squalane (96%) were obtained from Sigma–Aldrich (Lyon, France). Nitric acid 65% (HNO₃) was purchased from Carlo-Erba (Barcelona, Spain). Sodium stearate (98.8%) was obtained from TCI (Tokyo, Japan). Oleic acid (99%) was purchased from Alfa Aesar (Lancashire, UK) while dibenzylether (DBE, 99%) was purchased from Acros Organic (Waltham, Massachusetts, USA).

Carbula marginella adults (Fig. 1) were collected in the village of Boudtenga (12° 29′
11′′ N; 1° 15′ 57′′ W) in the North Sudanian zone in December 2016. C. butyrospermi (Fig. 2), at the fourth stage of its development (larval stage), was collected in the South Sudanian zone from July to August 2015 and 2017 in the village of Koumi (N 11° 07′ 54.7′′, W 004° 25′ 41.5′′). The insects were immediately placed in cooler boxes containing ice and brought to the laboratory. Specimen were identified at the Department of Environment and Forests using the Scholtz classification [18 (link)]. Samples were cleaned and the inedible parts were removed. Then, they were washed with distilled water and dried for 24 h in an oven at 40–50 °C.Fig. 1

Carbula marginella

Fig. 2

Cirina butyrospermi

Alpha-chymotrypsin (MP Biomedicals, USA), nitric acid (Carlo Erba, France, 96%), boric acid (Sigma-Aldrich, USA, 98%), ethanol (Chromasolv, absolute, for HPLC, Sigma-Aldrich, Germany), n-hexane (Chromasolv, Germany), hydrochloric acid (Carlo Erba, France, 37%), Kjeldahl catalyst (Carlo Erba, Germany), phenylisothiocyanate (Thermo Scientific, USA), methanol (HPLC Gradient Grade for free amino acids analysis, Prolabo Chemicals, France), Pico Tag diluent (Waters, USA), sodium hydroxide (Carlo Erbo, France), triethylamine (Sigma-Aldrich, Belgium, 99%) and trypsin from bovine pancreas (Sigma Aldrich, USA) were used.