Primacs snc 100

The biochemical determinations were performed on muscle tissue samples, following the procedures outlined by the Association of Official Analytical Chemists [54 ]. The ash content (%) of the sample was determined using a muffle furnace (Nabertherm, Lilienthal, Germany, Applied Scientific Instruments Co., Ltd., Bangkok, Thailand) at 525 ± 25 °C for 8 h. The moisture content (% dry weight) was determined by drying the meat samples at 105 °C in a convection oven (Jeiotech, Jeio Tech Co., Inc., Seoul, Republic of Korea) until a constant weight was obtained. After determining the moisture content, dry samples were finely ground and used to determine of protein and fats. Crude protein content (%) was calculated by converting the nitrogen content (using the common conversion factor of N × 6.25), quantified by Dumas’s method, through combustion of dry samples at 1100 °C (Primacs SNC 100, Skalar Analytical B.V., Breda, The Netherlands). Lipid content (%) in fish tissue was analyzed using the Soxhlet extraction method with petroleum ether as the solvent (C. Gerhardt GmbH & Co. KG, Königswinter, Germany).

Different soil chemical properties were analyzed. In brief, soil pH was measured after preparing a soil–water suspension. Total organic carbon analyzer (Primacs SNC-100, Skalar Analytical, Breda, The Netherlands) was used to determine OM. Total N was estimated through Kjeldahl method and molecular absorption spectrophotometry was used for its quantification [43 ]. Extraction of P and K was performed using the Egnér–Riehm method, and for determination a spectrophotometer and a flame emission photometer (iCE™ 3300 AAS, Thermo Scientific^TM, Breda, North Brabant, The Netherlands) were used, respectively. Atomic absorption spectrophotometry and subsequent ammonium acetate extraction at pH 7.0 were used to measure the amounts of exchangeable cations and bases [44 (link)]. Exchangeable acidity was measured using the titration method [45 ]. CEC_e was measured by summing exchangeable acidity and exchangeable bases, and the degree of base saturation was estimated by adding up the exchangeable bases, dividing it by CEC_e, and then multiplying by 100.

Soil pH was determined one hour after preparing a soil–water suspension. Organic matter content was determined using a total organic carbon analyzer (Primacs^SNC-100, Skalar Analytical, Breda, The Netherlands). Total nitrogen was assessed by the Kjeldahl method, and the quantification was done using molecular absorption spectrophotometry [24 ]. The Egnér–Riehm method was used to extract P and K, and a spectrophotometer and a flame emission photometer (iCE™ 3300 AAS, Thermo Scientific^TM, Breda, North Brabant, The Netherlands) was used for their respective determination. Exchangeable cations, or exchangeable bases, were measured by atomic absorption spectrophotometry, following the ammonium acetate extraction at a pH of 7.0 [25 (link)]. Titration method described in Thomas was used to determine exchangeable acidity [26 ]. Effective cation exchange capacity was calculated by summing exchangeable bases and exchangeable acidity. The degree of base saturation was measured by summing the exchangeable bases, dividing it by the ECEC, and then multiplying by 100.