Exploding bridgewire detonator simulator

Tests indicate that electric detonator simulators of the exploding bridgewire type will not fire as a result of the application of a direct current power of one watt for 5 minutes. The detonator also will not fire if the protective gap fails and the firing stimulus is inadvertently applied

Food Chemistry: Food quality and new analytical approaches

Peer Reviewe

Synthesis, characterization and application of ion imprinted poly(vinylimidazole) for zinc ion extraction/preconcentration with faas determination

In this paper, we describe the synthesis of an ion imprinted polymer (IIP) by homogeneous polymerization and its use in solid-phase to extract and preconcentrate zinc ions. Under optimal conditions (pH 5.0, preconcentration flow rate of 12.0 mL min-1, and eluted with 1.0 mol L-1 HNO3) this procedure allows the determination of zinc with an enrichment factor of 10.2, and with limits of detection and quantification of 1.5 and 5.0 µg L-1, respectively. The accuracy of our results was confirmed by analysis of tap water and certified reference materials: NIST 1570a (Spinach leaves) and NIST 1515 (Apple leaves)371636

Application of chitosan functionalized with 3,4-dihydroxy benzoic acid moiety for on-line preconcentration and determination of trace elements in water samples

Chitosan resin functionalized with 3,4-dihydroxy benzoic acid (CCTS-DHBA resin) was used as a packing material for flow injection (FI) on-line mini-column preconcentration in combination with inductively coupled plasma-atomic emission spectrometry (ICP-AES) for the determination of trace elements such as silver, bismuth, copper, gallium, indium, molybdenum, nickel, uranium, and vanadium in environmental waters. A 5-mL aliquot of sample (pH 5.5) was introduced to the minicolumn for the adsorption/preconcentration of the metal ions, and the collected analytes on the mini-column were eluted with 2 M HNO3, and the eluates was subsequently transported via direct injection to the nebulizer of ICP-AES for quantification. The parameters affecting on the sensitivity, such as sample pH, sample flow rate, eluent concentration, and eluent flow rate, were carefully examined. Alkali and alkaline earth metal ions commonly existing in river water and seawater did not affect the analysis of metals. Under the optimum conditions, the method allowed the determination of metal ions with detection limits of 0.08 ng mL(-1) (Ag), 0.9 ng mL(-1) (Bi), 0.07 ng mL(-1) (Cu), 0.9 ng mL(-1) (Ga), 0.9 ng mL(-1) (In), 0.08 ng mL(-1) (Mo), 0.09 ng mL(-1) (Ni), 0.9 ng mL(-1) (U), and 0.08 ng mL(-1) (V). By using 5 mL of sample solution, the enrichment factor and collection efficiency were 8-12 fold and 96-102%, respectively, whereas the sample throughput was 7 samples/hour. The method was validated by determining metal ions in certified reference material of river water (SLRS-4) and nearshore seawater (CASS-4), and its applicability was further demonstrated to river water and seawater samples.</p

Preparation of a new restricted access molecularly imprinted hybrid adsorbent for the extraction of folic acid from milk powder samples

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)A new hybrid molecularly imprinted polymer (MIP) combined with restricted access (RAM) has been synthesized based on random free-radical polymerization and a sol-gel process. From competitive adsorption studies by using the RAM-MIP and RAM-NIP with folic acid and structurally similar molecules (caffeine, 4-aminobenzamide or paracetamol), relative selectivity coefficients (k) higher than one unit were achieved, indicating good recognition selectivity for folic acid. The percentage of BSA protein exclusion was higher for the RAM-MIP (55.3 + 2.0) as compared to the MIP (35.9 + 2.5%). The solid phase extraction (SPE) procedure was performed by loading the acid extract from milk powder samples previously submitted to saponification and acidification with 10% trichloroacetic acid (TCA) until pH 1.5, through 100 mg of RAM-MIP packed into SPE cartridge. The elution step was carried out by using a mixture of acetonitrile : 0.266 mol L-1 acetate buffer at pH 5.7 (15 : 85, v/v), the same composition of the mobile phase of HPLC. The intra-day precision (n = 10) of the procedure assessed as relative standard deviation (RSD) was 4.7 and 4.1% for the respective concentrations of 20.0 and 150.0 mu g L-1. The applicability of the method was attested by analysis of different brands of milk powder samples fortified with folic acid, as well as by high recovery percentages 95.0-108.4% obtained upon addition and recovery tests. The cleanup process accomplished by RAM-MIP was so efficient that very few remaining matrix components were detected in the eluate by high performance liquid chromatography.A new hybrid molecularly imprinted polymer (MIP) combined with restricted access (RAM) has been synthesized based on random free-radical polymerization and a sol–gel process. From competitive adsorption studies by using the RAM-MIP and RAM-NIP with folic83656665COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO ARAUCÁRIA DE APOIO AO DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO DO PARANÁ - FACONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)sem informaçãosem informaçãosem informaçãoWe acknowledge the CAPES, INCT-BIOANALITICA, FUNDAÇÃO ARAUCÁRIA do PARANÁ, SETI do Paraná and CNPq for financial support. The authors also would like to thank all the anonymous reviewers for their valuable comments and suggestions to improve the quality