PRELIMINARY STUDY OF ARSENIC CONTENT AND TOXICITY ASSESSMENT IN RICE FROM INDONESIA

Over 50 percent of the world's population consumes rice as a staple food. However, due to natural and anthropogenic activity, heavy metals, particularly arsenic (As), can be found in rice. This has become a worldwide concern because of the high level of consumption of rice and its processed products, as well as the long-term consequences. Information on dietary arsenic exposure in raw and cooked rice and its content quality in Indonesia is limited; however, its availability is essential for estimating toxicity level intake. Therefore, an advanced, accurate, fast, relatively easy, and environmentally friendly arsenic analysis method, such as total X-ray fluorescence (TXRF) and a line equation approach, is needed. It is necessary to evaluate arsenic content and inorganic arsenic (i-As) in rice. The research aimed to assess preliminary dietary arsenic exposure, evaluate rice's inorganic arsenic concentration, and assess toxicity levels. Toxicity level estimation of arsenic exposure was done by determining the hazard quotient (HQ). The results showed that t-As and i-As in rice were 0.071-0.104 mg/kg and 0.050-0.073 mg/kg (wet base), respectively. The mean percentage of i-As reached 70% from the t-As, and the toxicity level of arsenic in cooked rice is low, as shown by the value of HQ < 1. The estimated result indicates no chronic non-carcinogenic effect caused by these samples

Diaminoalkane as Spacer Arm between Polystyrene and - Cylodextrin in Affinity Chromatography for -Amylase Separation

ABSTRACT Stationary phase design in affinity chromatography has to fulfill at least two requirements: non-specific interaction between solid support and or spacer arm and protein target or others is minimal and specific interaction between ligand and protein target is maximal. In this study, stationary phases that consist of polystyrene (PS) as solid support, diaminoalkane as spacer arm and with and without βCD as a ligand are performed in α-amylase separation. Therefore, the research was carried out in two steps; stationary phase preparation and adsorption parameter determination towards α-amylase. Stationary phases that consist of PS, 1,6-diaminohexane and βCD (PS-DAH-βCD) and without βCD (PS-DAH) were synthesized. Stationary phase structure was confirmed by FTIR, , respectively. Due to adsorption parameters, PS-DAP-βCD offer the best adsorption capacity and selectivity as stationary phase in affinity chromatography for α-amylase separation

Molecularly Imprinted Polymer Solid-Phase Extraction (MISPE) for the Determination of Dinitro-ortho-cresol (DNOC) and Its Risk Assessment in Tomatoes

In this study, the molecularly imprinted polymer solid-phase extraction (MISPE) method for the determination of dinitro-ortho-cresol (DNOC) before HPLC (High-performance liquid chromatography) analysis was conducted. This study aims to analyze the sorption behavior and the potential use of molecularly imprinted polymers (MIP) for DNOC extraction. MIP was prepared using a combination of methacrylic acid as the functional monomer; ethylene glycol dimethacrylate as the crosslinker, benzoyl peroxide as the initiator, and acetonitrile as the porogen. The results showed that the optimum adsorption of the material was achieved at pH 5 for a contact time of 30 min with an adsorption capacity of 137 mg/g. The ideal eluent for desorption was a mixture of methanol and acetic acid with a ratio of 3:1. The calculations showed that the adsorption process followed the Sips adsorption isotherm model (n = 0.967), which indicated adsorption on both homogeneous and monolayer surfaces. Reusability studies that were conducted via three consecutive adsorption-desorption cycles resulted in recovery values of 109.4%, 108.8%, and 101.1%. The concentration of DNOC obtained from tomato samples was 0.65 mg/kg with a recovery rate of 87.17%; this was within the tolerable range between 80% and 110%. Based on the high recovery and low LoQ, this method can be used to quantify DNOC quickly

Sintesis dan karakterisasi poly (Anthranilic Acid-Co-Formaldehyde) untuk adsorpsi ion Pb(II)

Selain memberikan dampak positif, perkembangan industri yang pesat juga dapat memberikan dampak negatif berupa limbah industri penyebab pencemaran lingkungan. Timbal merupakan salah satu ion logam berat yang menjadi indikator primer pencemaran menurut United States Environmental Protection Agency (US EPA). Penentuan konsentrasi timbal secara langsung dalam sampel lingkungan seringkali sulit dilakukan karena terdapat pada konsentrasi renik dengan matriks yang rumit. Oleh karena itu, teknik prakonsentrasi yang dapat menyederhanakan matriks sangat diperlukan. Resin penukar ion, resin pengkhelat, dan ion imprinted polymers banyak digunakan untuk prakonsentrasi unsur renik. Poly (anthranilic acid-co-formaldehyde) merupakan polimer yang disintesis dengan cara mencampurkan asam anthranilat, formaldehida, dan HCl. Karakterisasi poly(anthranilic acid-co-formaldehyde) telah dilakukan menggunakan FTIR dan SEM. Hasil karakterisasi mengindikasikan bahwa reaksi polimerisasi telah terbentuk yang ditunjukkan dengan adanya vibrasi CH2 bridge. Poly (anthranilic acid-co-formaldehyde) memiliki morfologi permukaan yang relatif halus dan berpori. Metode yang digunakan untuk mempelajari kemampuan adsorpsi adalah metode batch. Kapasitas adsorpsi poly (anthranilic acid-co-formaldehyde) terhadap ion Pb(II) adalah 16,37 mg/g pada pH 5 dengan waktu kontak 10 menit

Ion-pair reversed-phase chromatography for speciation of organotin compounds

Objective: Ion-pair reversed-phase chromatography (IP-RP) has been investigated for speciation of dibutyltin (DBT), tributyltin (TBT), and triphenyltin (TPhT). The influence of several parameters (pH, alkyl chain length, concentration of the ion pair reagent) has been studied to determine the best chromatographic conditions. Methods: Separation of the three organotin compounds was achieved on a C8-bonded silica column using a mixture of methanol, water, and acetic acid (80:19:1) as eluent, containing 1 mmol/L decane sulfonic acid as ion pairing reagent. The eluates were detected on-line by hydride generation-quartz furnace atomic absorption spectrophotometry (HG-QFAAS). Results: The resolving power of this developed method for separation of the organotins species at above conditions was shown by the values of fundamental chromatographic parameters. The capacity factors (k’) for DBT, TBT and TPhT species were 0.27, 2.54, and 5.92 respectively. Resolution (Rs) values for DBT-TBT and TBT-TPhT separation were 2.92 and 2.42 respectively, while the selectivity for DBT-TBT and TBT-TPhT were 9.76 and 3.50 respectively. Conclusion: The developed IP-RP-HG-QFAAS chromatography technique can separate DBT, TBT, and TPhT with good performance which is shown by the chromatographic parameters produced

Pemisahan Unsur tanah Jarang Dari Mineral Monasit Bangka Dengan Teknik Solvent Impregnated Resin(Sir)

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