scholarly journals Analisis Pengukuran Logam Cu, Fe, Mn, dan Pb pada Variasi Preparasi Suhu dan Pelarut

WARTA AKAB ◽  
2021 ◽  
Vol 45 (2) ◽  
Author(s):  
Ahmad Zakaria ◽  
Aynuddin Aynuddin ◽  
Wittri Djasmasari
Keyword(s):  

Teknik preparasi sampel memainkan peran penting dalam tujuan analisis. Teknik preparasi sampel logam berat menggunakan SSA-Nyala umumnya dengan penambahan asam pekat seperti asam nitrat (HNO3), asam klorida (HCl), asam sulfat (H2SO4), asam perklorat (HClO4), atau campurannya. Meskipun HNO3 telah diterima dan digunakan sebagai pengencer logam berat untuk mengatur pH di bawah 2, tetapi tidak banyak makalah atau laporan penelitian yang mengeksplorasi suhu atau kondisi pH alternatif dalam analisis sampel logam berat. Tujuan dari penelitian ini adalah untuk mengetahui suhu dan pH optimum dalam analisis logam Cu, Fe, Pb, dan Mn. Penelitian dilakukan dengan memvariasikan suhu dan konsentrasi HNO3 dalam larutan standar. Hasil pengukuran kemudian dianalisis linieritas, sensitivitas, dan deviasinya. Data menunjukkan bahwa tidak ada perbedaan yang signifikan antara penggunaan HNO3 dengan konsentrasi rendah dan tinggi. Hal ini menunjukkan bahwa tidak perlu menggunakan HNO3 berlebihan dalam preparasi sampel. Penelitian lebih lanjut diperlukan untuk mensimulasikan teknik preparasi pada spesies logam berat yang berbeda. Kata kunci : Logam Berat; SSA-Nyala; pH; Suhu

1974 ◽  
Vol 32 (02/03) ◽  
pp. 457-464
Author(s):  
Paul C. French ◽  
Jan J. Sixma ◽  
Holm Holmsen

SummaryAdenine uptake into isolated platelet membranes had about the same Km (151 ± 21 • 9 nM) as uptake into intact cells (159 ± 21 nM) and was also competitively inhibited by papaverine and hypoxanthine. No uptake occurred at 0° and accumulated adenine was converted to AMP. AMP was not firmly bound to protein as judged by chromatography of triton X-100 solubilized membranes on Sephadex G25. The pH optimum for adenine uptake was at pH 5-5. Exogenous 5-phosphoribosyl-l-pyrophos- phate strongly stimulated uptake. These data may be explained by uptake of adenine by facilitated diffusion followed by conversion to AMP by adenine phosphoribosyltransferase but group translocation cannot be entirely excluded.


1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.


al-Kimiya ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 47-54
Author(s):  
Hesty Nuur Hanifah ◽  
Ginayanti Hadisoebroto ◽  
Turyati Turyati ◽  
Ineu Sintia Anggraeni

Koagulasi merupakan tahap awal dalam proses pengolahan limbah cair. Salah satu industri yang berpotensi untuk menimbulkan pencemaran air bila limbah cairnya tidak dikelola dengan baik adalah industri farmasi. Cangkang telur ayam ras dan kulit pisang kepok merupakan limbah padat yang belum termanfaatkan, padahal kedua bahan tersebut mengandung zat-zat yang bisa membantu dalam proses koagulasi. Oleh karena itu, peneliti tertarik untuk mengembangkan biokoagulan dari cangkang telur ayam ras dan kulit pisang kepok. Penelitian ini bertujuan untuk mengetahui efektivitas dari cangkang telur ayam ras dan kulit pisang kepok sebagai biokoagulan dalam menurunkan nilai turbiditas, TDS (Total Disolved Solid) dan TSS (Total Suspended Solid) dari limbah cair industri farmasi. Alat yang digunakan dalam penelitian ini adalah jartest. Sampel air limbah yang digunakan dalam percobaan ini yaitu sampel air limbah industri farmasi dari PT Sinkona Indonesia Lestari. Berdasarkan hasil penelitian  menunjukkan bahwa biokoagulan cangkang telur ayam mempunyai dosis optimum yaitu 50 g/500 mL dan pada pH optimum 8 terjadi penurunan turbiditas sebesar 81,18%, TDS sebesar 24,3% dan TSS sebesar 82,05%. Sedangkan  biokoagulan kulit pisang kepok mempunyai dosis optimum 5 g/500 ml dan pada pH optimum 2 terjadi penurunan  turbiditas sebesar   94,9%, TDS 51,3% dan TSS  83,2%. Dari data tersebut bisa disimpulkan bahwa cangkang telur ayam ras dan kulit pisang kepok bisa dimanfaatkan sebagai biokoagulan untuk pengolahan limbah cair dari industri farmasi.


Author(s):  
Е. M. Serba ◽  
М. B. Overchenko ◽  
L. V. Rimareva ◽  
N. I. Ignatova ◽  
А. E. Orekhova ◽  
...  

In the production of alcohol in the preparation of grain raw materials for fermentation, the main role is given to enzyme preparations of amylolytic action, which are key enzymes that catalyze the hydrolysis of starch. Amylolytic enzyme preparations with a different composition of enzymes and their level of activity, a mechanism of biocatalytic effect on starch, and a range of thermal and pH optimum are widely represented on the Russian market. The development of optimal conditions for the preparation of grain wort, the rational selection and dosage of concentrated enzyme preparations, the properties of which correspond to the parameters of the technological process, will ensure the effective preparation of starch for fermentation, and increase the profitability of alcohol production. The aim of this work was to study the influence of enzyme preparations of amylolytic action and the conditions of their use on the efficiency of the process of alcoholic fermentation and the yield of the final product, ethanol. The effect of various dosages of enzyme preparations of glucoamylase action, with a different ratio of the main enzyme glucoamylase and minor enzyme α-amylase, as well as methods for preparing wheat wort on the process of alcoholic fermentation, was studied. It was found that the enzyme preparation, the source of glucoamylase, in which α-amylase was present in a ratio of 15: 1 (in terms of activity level), turned out to be more effective in fermenting prepared wheat wort: its optimal dosage was 8 units. GLS / g starch. The presence of a sufficient amount of α-amylase in this preparation compensated for the dosage of thermostable α-amylase. The alcohol concentration in the mash was 10.2% vol., The alcohol yield was 67.9 cm3 / 100 g of starch. When glucoamylase with a lower ratio of the main and minor enzyme (75: 1) was used at the saccharification stage, an increase in the wort fermentation depth was observed with an increase in the concentration of glucoamylase to 9-10 units of GLS / g and α-amylase to 0.5 units. AC / g. It was also found that an increase in the duration of enzymatic-hydrolytic preparation of the wort had a positive effect on the fermentation process, the alcohol concentration in the mash increased to 10.2 vol.%. It was shown that the introduction of proteases into the wort helps to reduce the viscosity of grain wort, enriching it with assimilable yeast amino acids, which leads to an increase in the yield of alcohol. It has been confirmed that the synergy of the action of enzymes of amylolytic and proteolytic effects on polymers of grain raw materials allows to increase the efficiency of their conversion to ethanol. The conditions of enzymatic-hydrolytic processing of grain raw materials for fermentation are developed. The use of the digestion stage did not significantly affect the fermentation results of wheat wort.


Arena Tekstil ◽  
2014 ◽  
Vol 29 (1) ◽  
Author(s):  
Rizka Yulina ◽  
Srie Gustiani ◽  
Wulan Septiani

Selulosa bakterial mempunyai sifat mekanik yang baik untuk digunakan sebagai membran pada proses pengolahan air limbah tekstil. Pada penelitian ini dilakukan pembuatan dan karakterisasi serat hollow dari bahan baku selulosa bakterial nata de coco dengan penambahan nanopartikel ZnO sebagai fotokatalis terimmobilisasi. Selulosa bakterial disintesis menggunakan bakteri Acetobacter xylinum di dalam medium air kelapa dan gula. Selulosa bakterial dilarutkan bersama dengan nanopartikel ZnO menggunakan pelarut cuprietilen diamina (Cuen) dengan variasi selulosa bakterial 2,25% dan 2,50%. Serat berbentuk hollow dihasilkan dari proses wet spinning menggunakan koagulan NaOH. Serat hollow yang telah melalui koagulan kemudian direndam dalam larutan asam, gliserol, dan alkohol, dengan variasi waktu perendaman asam selama 1 dan 2 hari. Uji kekuatan tarik menunjukkan hasil yang terbaik yakni sebesar 815,72 gf pada konsentrasi selulosa bakterial 2,50% dan perendaman asam selama 2 hari. Dari hasil uji gugus fungsi menggunakan spektroskopi Fourier Transform Infra Red (FTIR), terdapat beberapa gugus fungsi yang menunjukkan keberadaan selulosa dan nanopartikel ZnO. Proses dekolorisasi fotokatalitik terhadap air limbah tekstil artifisial yang mengandung zat warna reaktif Remazol Black 5 (RB5) menunjukkan bahwa pH optimum proses penyisihan warna yakni pada pH 9 dan dihasilkan persen penyisihan warna yang tertinggi yaitu 90,32%. Pada kondisi yang sama, proses dekolorisasi RB5 menggunakan serat hollow tanpa nanopatikel ZnO hanya menghasilkan persen penyisihan warna sebesar 32,10%. Berdasarkan laju penyisihan zat warna, aktivitas degradasi fotokatalitik terbesar (k’ = 0,2615) diperoleh pada konsentrasi ZnO 10% dan konsentrasi zat warna RB5 10 ppm.


1980 ◽  
Vol 45 (4) ◽  
pp. 1099-1108 ◽  
Author(s):  
Mikuláš Chavko ◽  
Michal Bartík ◽  
Evžen Kasafírek

A polarographic study of the hydrolysis of [8-lysine]vasopressin and some hormonogens of the vasopressin series with the blood serum of women in the last week of pregnancy was studied. The dependence of hydrolysis on pH (pH optimum: 7.4-7.50, substrate concentration (Km 1.2 . 10-5M), pH stability and thermal stability were determined. The rate of hydrolysis of individual vasopressin analogues decreases in the order: [8-lysine]vasopressin > Nα-glycyl-prolyl[8-lysine]-vasopressin > Nα-leucyl-[8-lysine]vasopressin > Nα-alanyl-[8-lysine]vasopressin > Nα-phenyl alanyl-[8-lysine]vasopressin > Nα-diglycyl-[8-lysine]vasopressin > Nα-prolyl-[8-lysine]vasopressin > Nα-triglycyl-[8-lysine]vasopressin > Nα-sarcosyl-glycyl-[8-lysine]vasopressin. The degree of hydrolysis gradually increases to a multiple with the length of the pregnancy in consequence of the presence of oxytocine. However, vasopressin is also hydrolysed to a small extent with the enzymes from the blood sera of non-pregnant women. Under similar analytical conditions oxytocin was not hydrolysed with the sera of non-pregnant women and therefore oxytocin is a more suitable substrate than vasopressin for polarographic determination of serum oxytocinase.


1990 ◽  
Vol 55 (12) ◽  
pp. 2987-2999 ◽  
Author(s):  
Katarina Šedivá ◽  
Ivan Votruba ◽  
Antonín Holý ◽  
Ivan Rosenberg

Purine nucleoside phosphorylase (PNP) from mouse leukemia cells L1210 was purified to homogeneity by a combination of ion exchange and affinity chromatography using AE-Sepharose 4B and 9-(p-succinylaminobenzyl)hypoxanthine as the matrix and the ligand, respectively. The native enzyme has a molecular weight of 104 000 and consists of three subunits of equal molecular weight of 34 000. The results of isoelectric focusing showed that the enzyme is considerably microheterogeneous over the pI-range 4.0-5.8 and most likely consists of eight isozymes. The temperature and pH-optimum of phosphorolysis, purine nucleoside synthesis and also of transribosylation is identical, namely 55 °C and pH 7.4. The transribosylation reaction proceeds in the presence of phosphate only. The following Km-values (μmol l-1) were determined for phosphorolysis: inosine 40, 2'-deoxyinosine 47, guanosine 27, 2'-deoxyguanosine 32. The Km-values (μmol l-1) of purine riboside and deoxyriboside synthesis are lower than the values for phosphorolysis (hypoxanthine 18 and 34, resp., guanine 8 and 11, resp.). An affinity lower by one order shows PNP for (-D-ribose-1-phosphate, (-D-2-deoxyribose-1-phosphate (Km = 200 μmol l-1 in both cases) and phosphate (Km = 805 μmol l-1). The substrate specificity of the enzyme was also studied: positions N(1), C(2) and C(8) are decisive for the binding of the substrate (purine nucleoside).


2011 ◽  
Vol 57 (7) ◽  
pp. 606-610 ◽  
Author(s):  
Rumyana Eneva ◽  
Stephan Engibarov ◽  
Tanya Strateva ◽  
Radoslav Abrashev ◽  
Ignat Abrashev

Neuraminidase is a key factor in the infectious process of many viruses and pathogenic bacteria. The neuraminidase enzyme secreted by the etiological agent of cholera — Vibrio cholerae О1 — is well studied in contrast with the one produced by non-O1/non-O139 V. cholerae. Environmental non-O1/non-O139 V. cholerae isolates from Bulgaria were screened for production of neuraminidase. The presence of the neuraminidase gene nanH was detected in 18.5% of the strains. Тhe strain showing highest activity (30 U/mL), V. cholerae non-O1/13, was used to investigate the enzyme production in several media and at different aeration conditions. The highest production of extracellular neuraminidase was observed under microaerophilic conditions, which is possibly related to its role in the infection of intestine epithelium, where the oxygen content is low. On the other hand, this is another advantage of the microbe in such microaerophilic environments as sediments and lake mud. The highest production of intracellular neuraminidase was observed at anaerobic conditions. The ratio of extracellular to intracellular neuraminidase production in V. cholerae was investigated. The temperature optimum of the enzyme was determined to be 50 °C and the pH optimum to be 5.6–5.8.


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