Model optima 8000

Chemicals that were used in the analysis are analytical grades. 35.4% of HCl (Loba, chemical Ltd, laboratory reagent, India) and 69% (Analytical R, IMO: Nitric acid solution BDH Laboratory supplies, England) of HNO₃ were used to digest the water samples. Stock standard solution of the metals Cu (1000 mg/L), Fe (1000 mg/L), Mn (1000 mg/L), Cd (1000 mg/L), Zn (1000 mg/L), Pb (1000 mg/L), Cr (1000 mg/L), and Co (1000 mg/L) prepared for inductively coupled plasma-optical emission spectrophotometer (ICP-OES), (Perkin Elmer MODEL Optima 8000, U.S.A.) were used for the preparation of calibration curves for the determination of metals in the sample. Distilled water was used for cleaning of glassware and dilution of sample solutions.

The measurements of the calcium concentration in the crosslinked samples were performed by inductive coupled plasma-optical emission spectrophotometer (Model Optima 8000, Perkin Elmer, Waltham, MA, USA). Composite films (about 10 mg) were dissolved in 20 mL of a 2 wt% sodium citrate solution and three measurements were carried out on each sample.

Fresh serum and gut fluid were prepared from the different insect species. The pH values of serum and gut fluids were measured using an InLab^® Ultra-Micro pH electrode (Mettler-Toledo, Greifensee, Switzerland) (Harrison, 2001 (link)). For magnesium concentration measurement, the serum and gut fluids were first digested with HNO₃ for 40 min with a microwave digestion system (Milestone Ethos T, Sorisole, BG, Italy), after which digested solutions were transferred to volumetric flasks and diluted with 1% HNO₃ to a final volume of 50 mL. The magnesium ion concentration in the solutions were measured using inductively coupled plasma-mass spectrometry (ICP-MS) with axial and radial viewing plasma configuration Model Optima 8000 (PerkinElmer, Waltham, MA, United States) (Zhou et al., 2007 (link)).