The effect of saturation Methods on natural gypsum rocks

When the gypsum rock is exposed to the relative humidity in a closed environment for a continuous period, the result is an increase in the weight of these rocks after the passage of the first 24 hours, and there is no effect on the percentage of gypsum that the rocks contain, as the weight increase occurred at the same time for the different gypsum ratios. For rocks submerged in potable water and located within a humid environment, most of these rocks witnessed weight gain, with some exhibiting dissolving behavior. As for the gypsum rocks submerged with water saturated with aqueous calcium sulfate salt, they witnessed weight gain without any solubility. It is worth noting the important effect that relative humidity plays in the atmosphere at high levels, as it stimulated the saturation property to cover and overcome the famous property of gypsum rocks, which is the melting at high humidity.

Removal of Lead, Cadmium, and Aluminum Sulfate from Simulated and Real Water with Native and Oxidized Starches

The separation of toxic pollutants such as Pb2+, Cd2+, and Al3+ from water is a constant challenge as contamination of natural water bodies is increasing. Al3+ and especially Pb2+ and Cd2+ are ecotoxic and highly toxic for humans, even in ppb concentrations, and therefore removal below a dangerous level is demanding. Herein, the potential adsorber material starch, being ecofriendly, cheap, and abundantly available, was investigated. Thus, four different native starch samples (potato, corn, waxy corn, and wheat starch) and two oxidized starches (oxidized potato and corn starch) were comprehensively analyzed with streaming potential and charge density measurements, SEM-EDX, ATR-FTIR, 1H-NMR, and TGA. Subsequently, the starch samples were tested for the adsorption of Pb2+, Cd2+, and Al3+ from the respective sulfate salt solution. The adsorption process was analyzed by ICP-OES and SEM-EDX, and the adsorption isotherms were fitted comparing Langmuir, Sips, and Dubinin-Radushkevich models. Oxidized starch, for which chemical modification is one of the simplest, and also native potato starch were excellent natural adsorber materials for Al3+, Cd2+, and especially Pb2+ in the low concentration range, exhibiting maximum adsorption capacities of 84, 71, and 104 µmol/g for oxidized potato starch, respectively.

Tripodal, Squaramide-Based Ion Pair Receptor for Effective Extraction of Sulfate Salt

Combining three features—the high affinity of squaramides toward anions, cooperation in ion pair binding and preorganization of the binding domains in the tripodal platform—led to the effective receptor 2. The lack of at least one of these key elements in the structures of reference receptors 3 and 4 caused a lower affinity towards ion pairs. Receptor 2 was found to form an intramolecular network in wet chloroform, which changed into inorganic–organic associates after contact with ions and allowed salts to be extracted from an aqueous to an organic phase. The disparity in the binding mode of 2 with sulfates and with other monovalent anions led to the selective extraction of extremely hydrated sulfate anions in the presence of more lipophilic salts, thus overcoming the Hofmeister series.

ANALISIS HASIL FRAKSINASI PROTEASE DAN LIPASE YANG BERASAL DARI SALURAN PENCERNAAN UDANG VANAME (Litopenaeus vannamei)

Analysis of Protease and Lipase Fractionation Originated from the Digestive Tract of Vannamei Shrimp (Litopenaeus vannamei) Vannamei shrimp is a fishery commodity with a high consumption value, so it has an impact of high shrimp waste in the form of head and skin. The digestive tract connected to the head of the vaname shrimp (Litopenaeus vannamei) contains digestive enzymes, including proteases and lipases. This study aims to obtain the protein fraction that has the highest protease and lipase activity. The separation method used was centrifugation followed by precipitation using ammonium sulfate salt and dialysis. The dialysate was purified by gel filtration chromatography at a volume retention of 10 drops per tube. The proteolytic and lipolytic enzyme activity of the fraction was measured using a spectrophotometer. The results showed that fraction 102 had the highest protease activity value of 96.3924 U / mL, while fraction 100 had the highest lipase activity of 531.07 U / mL. This study showed that in the digestive tract of vaname shrimp, protease and lipase activity increased with the level of purity. Keywords: digestive enzymes, gel filtration chromatography, lipase, protease, vannamei shrimp ABSTRAK Udang vaname merupakan komoditi perikanan dengan nilai konsumsi yang tinggi, sehingga berdampak pula dengan tingginya limbah udang yang berupa kepala dan kulit. Saluran pencernaan yang terhubung dengan kepala udang vaname (Litopenaeus vannamei) mengandung enzim pencernaan, diantaranya protease dan lipase. Penelitian ini bertujuan untuk mendapatkan fraksi protein yang memiliki aktivitas protease dan lipase tertinggi. Metode pemisahan yang dilakukan adalah sentrifugasi dilanjutkan dengan pengendapan menggunakan garam ammonium sulfat dan dialisis. Dialisat dimurnikan dengan kromatografi filtrasi gel pada retensi volume sebanyak 10 tetes tiap tabung. Aktivitas enzim proteolitik dan lipolitik fraksi diukur menggunakan spektrofotometer. Hasil menunjukkan bahwa fraksi 102 memiliki nilai aktivitas protease tertinggi sebesar 96,3924 U mL–1, sedangkan fraksi 100 memiliki aktivitas lipase tertinggi sebesar 531,07 U mL–1. Penelitian ini menunjukkan bahwa pada saluran pencernaan udang vaname terdapat aktivitas protease dan lipase yang meningkat seiring dengan tingkat kemurniannya.