Optical fiber mercury biosensor based on immobilized urease and bromothymol blue onto the alginate-chitosan membrane in the flow-system

An optical fiber biosensor has been developed for the detection of mercury ion based on inhibition of urease immobilized onto alginate–chitosan membrane, coupled with bromothymol blue (BTB) in the flow system. To get a good performance of the biosensor toward Hg(II) ion detection, the experimental parameters of the biosensor were optimized. Here, the maximum wavelength was detected at 580 nm, with the optimum response at pH of 6. The calibration curve had a dynamic working range at 10 to 500 μg/L of Hg(II) ion with a detection limit of 12.1 μg/L biosensor has been performed by the addition of 1 mM ethylenediaminetetraacetic acid (EDTA) solution, in which five-time cycles have been achieved with the inhibition decrease to 9.94% from the original biosensor response. Applying the biosensor to the real samples showed conformity of results with the reference method, cold vapor atomic absorption spectrometry (CV-AAS). Therefore, this biosensor can be used as a method for routine analysis in the determination of Hg(II) concentration in an aqueous sample.

Analisis Kadar Merkuri, Derajat Keasaman dan Faktor Risiko Kesehatan Pada Penambang Emas Tanpa Izin di Kecamatan Cempaka

Cempaka District is the largest traditional gold mining site in South Kalimantan Province. The purpose of this study was to identify levels of mercury (Hg), degree of acidity (pH) and health risk factors (age, years of service and completeness of PPE) in PETI workers in Cempaka District. The method used in this research is an observational method which is quantitative in nature with a cross-pontong approach, with a proportional difference test method. Sampling was carried out in the upstream and downstream areas. Measurement of water mercury levels was measured by means of Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) at the Industrial Research and Standardization Center (BARISTAND) in Banjarbaru City. As for the health risk factor variables using the method of observation and interviews with a questionnaire. The research sample was 40 active PETI workers. The results showed that the quality of water with mercury content exceeds the threshold, for the parameter of acidity (pH) within the norm limit of 6-9. Meanwhile, for health risk factors, PETI workers are mostly old, have worked ≥ 5 years and do not completely use PPE. Suggestions are to pay attention not to dispose of waste mercury (Hg) content into rivers. Keywords : Mercury levels ( Hg ); degrees acidity ( pH ); health risk factors; the workers Abstrak Kecamatan Cempaka merupakan tempat penambangan emas tradisional yang terbesar di Provinsi Kalimantan Selatan. Tujuan penelitian ini adalah untuk mengidentifikasi besar kadar merkuri (Hg), derajat keasaman (pH) dan faktor risiko kesehatan (Umur, masa kerja dan kelengkapan APD) pada pekerja PETI di Kecamatan Cempaka. Metode yang digunakan dalam penelitian ini yaitu metode observasional yang bersifat kuantitatif dengan pendekatan potong lintang, dengan metode uji-beda proporsi. Pengambilan sampel dilakukan pada daerah hulu dan hilir. Pengukuran kadar merkuri air diukur dengan alat Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) di Balai Riset dan Standarisasi Industri (BARISTAND) di Kota Banjarbaru. Sedangkan untuk variabel faktor risiko kesehatan menggunakan metode pengamatan dan wawancara dengan kuosioner. Sampel penelitian adalah pekerja PETI yang aktif sebanyak 40 responden. Hasil penelitian menunjukkan kualitas air dengan kandungan kadar merkuri melebihi ambang batas, untuk parameter derajat keasaman (pH) dalam batas norma sebesar 6-9. Sedangkan untuk faktor risiko kesehatan, pekerja PETI lebih banyak berumur tua , masa kerja ≥ 5 tahun dan tidak lengkap menggunakan APD. Saran untuk memperhatikan untuk tidak membuang limbah kandungan kadar merkuri (Hg) ke aliran sungai. Kata kunci : Kadar Merkuri (Hg); Derajat Keasaman (pH); Faktor Risiko kesehatan; Pekerja PETI

Separation and determination of mercury from nail and hair in petrochemical workers based on silver carbon nanotubes by microwave-assisted headspace sorbent trap

In this work, a robust method was developed for the determination of mercury in nail and hair in petrochemical workers. By experimental procedure, 100 mg of hair and nail of workers was prepared as a powder which dried in the oven for 20 min at 95oC. 20 mg of hair or nail samples added to reagents (HNO3/H2O2; 5:1) in polyethylene tube (PET) of microwave digestion and the mercury in resulting solution was removed with silver nanoparticles pasted on multi-walled carbon nanotubes (Ag-MWCNTs) which were placed in head space of separator. The mercury vapor was removed by Ag-MWCNTs as the headspace sorbent trap (HSST) under hood conditions. Finally, the mercury was online determined by cold vapor atomic absorption spectrometry after the heat process at 250oC in the presence of Ar gas. The capacity adsorptions of Ag-MWCNTs and MWCNTs for mercury removal were obtained 205.4 mg g-1 and 63.7 mg g-1, respectively.

Enhancement of Mercury Removal by Utilizing Catalytic Chelation Technique

Discharge of heavy metals released from industries has adverse effects on the environment. The development of a method that can safely remove heavy metals is still challenging. Therefore, the aim of this study is to propose catalytic chelation technique for the removal of mercury (Hg). Removal of Hg was carried out using the sodium acetate (CH3COONa) as the chelating agent and catalyzed by the heterogeneous alumina supported calcium oxide (CaO/Al2O3). The optimization was performed by applying the Response Surface Methodology (RSM) with the pH ranging from 7 to 10, a dosage of chelating agent from 400 ppm to 600 ppm, temperature from 33.5 to 37.5 oC, and time of reaction from 1 to 5 h. Hg content analysis was carried out using Flow Injection Mercury System based on cold vapor atomic absorption spectroscopy. X-ray diffraction (XRD) analysis revealed the presence of active sites on the catalyst. Field Emission Scanning Electron Microscopy (FESEM) analysis represented the formation of homogeneous particles on the catalyst surface. The Brunauer-Emmett-Teller (BET), Energy Dispersive X-Ray (EDX), and Fourier-transform Infrared Spectroscopy (FTIR) confirmed the surface area, the elemental composition, and functional groups of the catalyst, respectively. Moreover, the proposed method successfully achieved ±99 % of Hg removal.

Cloud point-dispersive liquid-liquid microextraction for preconcentration and determination of mercury in wastewater samples by methylsulfanyl thiophenol material

A efficient method based on 4-methylsulfanyl thiophenol (MSTP, C7H8S2) and ionic liquid ([BMIM][PF6]) was used for mercury (Hg) separation and preconcentration from wastewater of petrochemical industries. The 0.01 mile molar of MSTP, 80 mg of [BMIM][PF6] was diluted with 0.2 mL of ethanol (ET 98%). The mixture was injected to 10 mL of wastewater samples, shacked by ultrasonic bath for 5.0 min and cloudy solution was achieved by ionic liquid micelles at pH=7.0. The mercury ions was complexed with MSTP and extracted on micelles (IL/ET) by cloud point dispersive liquid-liquid microextraction (CP-DLLME) at 50oC before determined by cold vapor atomic absorption spectrometry (CV-AAS). The favorite extraction for mercury with low LOD (15 ng L-1) and good linear rages (0.05- 6.2 μg L-1) was achieved (RSD<5%). The main parameters such as, pH, sample volumes, amount of MSTP, amount of IL and ultra-sonic time were optimized.

Mercury determination in work place air and human biological samples based on dispersive liquid-liquid micro-extraction coupled with cold vapor atomic absorption spectrometry

Mercury as a Heavy metal is important factor must be determined and controlled in environmental air and biological. Mercury (Hg) accumulate in living tissues of human body. By NIOSH method, the briefing work place air of petrochemical worker was measured by cold vapor atomic absorption spectrometry(CV-AAS). For preparation and preconcentration samples before analysis a new method of dispersive liquid-liquid micro-extraction with ammonium salt of 1-pyrrolidinedithiocarbamate(APTC)combined with cold vapor atomic absorption spectroscopy, was developed.The influences of various analytical parameters including pH, APDC concentration and ionic liquid volume were investigated.Quantitative recoveries were obtained at pH 7.The enrichment factor was calculated as 5.The detection of limit(LOD)and detection of quantification(LOQ)of mercury were 0.06 and 0.2 μg L-1 respectively. In order accuracy determination the method,certified reference materials, NIST SRM 3133 Lot 061204 was analyzed and the recovery value 98% obtained. So, method of DLLME-APTC had good potential for preparation and preconcentration mercury samples before analysis.