Query: acrylamide ir

title: Development of a Sensitive and Rapid Method for Determination of Acrylamide in Bread by LC MS/MS and Analysis of Real Samples in Iran IR
abstract: A new sample preparation procedure and a liquid chromatography tandem mass spectrometry (LC MS/MS) method were developed for the quantitative analysis of acrylamide in bread. The method is based on sample extraction in methanol, purification with Carrez solutions and clean up with Primary Secondary Amine (PSA).The developed method offers an efficient, inexpensive, easy sample preparation and very sensitive procedure for determination of acrylamide in bread. The use of spiked calibration curves for constructing the calibration curve substantially reduced adverse matrix related effects. Recoveries were between 96 and 105.3% Good results were obtained with respect to repeatability (RSDs <11% The limit of detection and quantification of the method was 0.3 and 1 ng/g, respectively, which shows the method is very sensitive. The developed method was used for the determination of acrylamide in 26 traditional bread samples (Sangak) collected from Shiraz. The results showed that about 96% of Sangak bread samples were contaminated with acrylamide that 64.3 and 33.3 of semi industrial and traditional Sangak bread were higher than benchmark levels (50 ug/kg) respectively. There are a few reports concerning contamination of Sangak bread samples with acrylamide in Iran. Therefore, this method could be used for a comprehensive survey of acrylamide in Sangak bread samples in the country.

title: Monitoring the film formation process of polystyrene/poly acrylamide (PS/PAAm) composite films annealed by IR heating
abstract: In this study, UV visible(UVV) technique was used to probe the evolution of optical transmission during the film formation from composites of polystyrene (PS) latex particles and poly acrylamide (PAAm) films annealed by the infrared radiative heating (IRH) and convectional heating. Activation energies corresponding to the void closure and the interdiffusion stages were calculated. It was shown that the activation energy for the void closure processes of viscous flow from the composite films decreased considerably in IRH annealing technique. It was observed that IRH heating speeds up the film formation process and the decrease the required energy.

title: FT IR and computer modeling study of hydrogen bonding in N alkyl acrylamide toluene binary mixtures
abstract: Degree of hydrogen bonding driven self association of N n butyl)acrylamide, N n octyl)acrylamide, N sec octyl)acrylamide and N tert octyl)acrylamide in toluene was investigated using IR spectroscopy and computer modeling methods. Consistent results were demonstrated in the treatment of the Amide I (n C=O Amide II (d N H and n C N and Amide A (n N H absorption bands in IR spectra. Thus, the content of non bonded (free) amide groups decreases from 83 98% to 8 20% and the content of linear polyassociates increases to 80 90% with an increase in monomer concentration from 0.5 wt% to 50 wt% The content of cyclic dimers was equal to the value between 5 and 10% regardless of the initial monomer concentration. Dependences of the association degree and the content of the linear polyassociates on the concentration were found to be similar for all of the studied amides.

title: Temperature Induced Phase Separation and Hydration in Aqueous Polymer Solutions Studied by NMR and IR Spectroscopy: Comparison of Poly(N vinylcaprolactam) and Acrylamide Based Polymers
abstract: Using NMR and IR spectroscopy we compared the LCST behaviour of two types of thermoresponsive polymer systems, poly(N vinylcaprolactam) (PVCL) and acrylamide based polymers in aqueous solutions. We confirmed that during phase separation both PVCL and poly(N isopropylmethacrylamide) (PNIPMAm) chains undergo coil globule transition. At the same time some important differences were found for PVCL in comparison with PNIPMAm and poly(N isopropylacrylamide) (PNIPAm) especially a much lower level of dehydration of PVCL segments at temperatures above the phase transition. We assume that the origin of these differences can be in different structure of respective monomer units. From time dependences of ATR FTIR spectra it follows that the low degree of dehydration of PVCL segments is not changed with time. Small increase in the wavenumbers of the Amide I components of the hydrated PVCL carbonyl groups with time indicates that water released from PVCL mesoglobules with time, as revealed from NMR T2 measurements, might be mainly indirectly bound water.

title: Dummy molecularly imprinted polymers based on a green synthesis strategy for magnetic solid phase extraction of acrylamide in food samples.
abstract: In this work, novel dummy molecularly imprinted polymers (DMIP) with propanamide as a dummy template molecule were prepared based on a green synthesis strategy of less consumption of hazardous/organic reagents and at mild conditions for magnetic solid phase extraction (MSPE) of acrylamide in biscuit samples, followed by high performance liquid chromatography (HPLC) determination. The resultant DMIP was well characterized by FT IR, SEM, TEM and VSM, exhibiting uniform nanoscale coreshell structure and good magnetic property in favor of simple rapid separation. Several main variables influencing MSPE efficiency were investigated, including DMIP dosage, sample solution pH, extraction time and desorption solvent; central composite design (CCD) and response surface methodology (RSM) were employed to assist in the MSPE condition optimization with rapidity and reliability. Under optimized conditions, excellent linearity for acrylamide was obtained in the range of 5.0 5000.0 ug kg 1, and low detection and quantification limits were 1.3 ug kg 1 and 4.4 ug kg 1, respectively. The method recoveries at five spiked concentrations were found within 86.0 98.3% with relative standard deviations (RSDs) of 1.2 4.1% Furthermore, endogenous acrylamide was detected in five different biscuit samples and the RSDs values were lower than 3.3% The present study suggested promising perspectives of water compatible eco friendly DMIP based MSPE HPLC method for highly effective sample pretreatment and targeted analytes determination in complicated matrices.

title: Synthesis and characterization of lignosulfonate/acrylamide graft copolymers and their application in environmentally friendly water based drilling fluid
abstract: Acrylamide (AAm) was grafted onto lignosulfonate (LS) in the aqueous medium using two different H2O2/CaCl2 redox and potassium persulfate (KPS) thermal initiating systems at 30 and 55 degC, respectively. Resulting LS g PAAm graft copolymers were characterized by gravimetric, FT IR and 1H NMR methods, from which initiator type and AAm concentration dependency of the AAm conversion (XAAm) grafting percentage (G( grafting efficiency (GE) and copolymer structure were systematically evaluated. It was found that XAAm and G( can be affected significantly by the initiator type and AAm concentration while GE can mostly be affected only by the initiator type. Highest GE of 100% and grafting length of the PAAm chains onto LS was observed in the reaction LA 2 performed using redox initiator at 30 degC and initial weight ratio of AAm to LS of 20 while highest XAAm was observed in the reaction LA 3 performed using KPS initiator at 55 degC. Graft copolymers as well as LS with different amounts were used to prepare bentonite based tap water (TWF) sea water (SWF) and NaCl salt saturated water (SSWF) fluids. Rheological and fluid loss (FL) properties of the above fluids were evaluated before and after hot rolling at 250 degF for 4 h. It was found that when an amount of 2.45 3.5 g/350 ml water is used; graft copolymers obtained from reactions LA 2 and LA 3 are able to improve rheological properties and to control FL and pH values in the TWF and SSWF, respectively, at low and high temperatures. All fluids showed shear thinning behavior with a gel like structure under static conditions. Results revealed that thermal stability and salt resistance of the graft copolymers are high enough to be used as an effective additive in the high temperature and high salty water based drilling fluids (WBDFs) An attempt was made to establish a relationship between the graft copolymer structure and its aqueous solution properties in the various water based fluids. It was found that simultaneous higher GE (preferentially as high as 100% and XAAm (as high as possible) in the graft polymers can results in a structure with the best performance in the WBDFs.

title: Superabsorbent polymer based on guar gum graft acrylamide: synthesis and characterization
abstract: Superabsorbent polymers of guar gum graft acrylamide were synthesized using KPS as a free radical initiator in the presence of Tetra (ethylene glycol) diacrylate as a cross linker using solution graft copolymerization technique. The structures of the grafted copolymers GG g PAAm were characterized by FT IR spectroscopy thermo gravimetric and SEM analysis. The effect of reaction parameters such as concentration of guar gum, acrylamide, KPS, crosslinker (TEGDA) and NaOH (neutralizing agent) were optimized to achieve a superabsorbent polymers with high swelling capacity of 80 g/g (deionisied water) and 22 g/g (0.8 wt% sodium chloride solution) The swelling kinetics of the synthesized superabsorbent were analyzed by applying the Fickian diffusion model and the Schott's pseudo second order kinetics model, illuminating that chain leisure behavior during absorption had a great effect on whole absorbency.

title: Cellulose g poly (acrylamide co acrylic acid) polymeric bioadsorbent for the removal of toxic inorganic pollutants from wastewaters.
abstract: Cellulose biopolymer was functionalized by free graft copolymerization and used as a new adsorbent to eliminate toxic inorganic pollutants from wastewater. Functional graft copolymers from cellulose were characterized by FT IR spectroscopy, XRD, TGA, and SEM EDX techniques.Cellulose g poly (acrylamide co acrylic acid) polymer adsorbent showed high adsorption capacities for the Cd2+ Cu2+ Pb2+ and Zn2+ toxic metal ions, which were evidenced by the comparison with unmodified cellulose richsamples. Cellulose g poly (acrylamide co acrylic acid) polymer adsorbent was optimized with various adsorption parameters such as the effect of pH, contacttime, temperature, and metallic ions concentration. The maximum monolayer capacity qm calculated for Cd2+ Cu2+ Pb2+ Zn2+ were 101.73, 61.84, 209.64, and 55.04 mgg 1 respectively. Thus, these results proved that cellulose g poly (acrylamide co acrylic acid) graft copolymer adsorbent from cellulose rich biomass could potentially be used for the removal of pollutants from wastewater.

title: Synthesis of a hydrogel by grafting of acrylamide co sodium methacrylate onto chitosan for effective adsorption of Fuchsin basic dye.
abstract: This work was designed to produce effective adsorbent from acrylamide (AAm) sodium methacrylate (SMA) and chitosan (CTS) through free radical grafting polymerization for removing the Fuchsin dye from its solution. The gel fraction and the grafting parameters were studied, and the results showed maximum grafting percentage (1014.3% and gel fraction (83.5% when the molar ratio of SMA to AAm was 1: 1 (the best ratio) In addition, incorporation of SMA into the gel structure enhanced the swelling of the gel by 6.63 10.25 fold as compared with the AAm graft CTS gel. FT IR, TGA, DTG, DTA, and SEM were utilized to investigate the gels. Capacity for the adsorption of Fuchsin basic dye via batch process was tested and the impact of SMA, contact time, agitation rate, gel dose, dye concentration, temperature, and pH were studied. The maximum removal (97.2% was achieved at the best ratio. Best fitting was found by pseudo second order kinetic and Freundlich isotherm. Evaluation of the thermodynamic parameters was done, and it was found that the adsorption process was exothermic in nature and spontaneous and unfavorable at high temperature. The negative value of S 0.148 KJ K 1 mol 1) indicated the decrease in randomness at the solid liquid interface.

title: Effects of different roasting methods on formation of acrylamide in pistachio
abstract: Drying and roasting are conventional processes in the nut industry. However, roasting as an important procedure in nuts manufacturing may cause some physicochemical changes in nuts. Acrylamide is one of these chemical compounds that is formed due to the roasting process. Acrylamide is known as a neurotoxicant, carcinogen, and reproductive toxicant. In this study, raw and salted pistachios were roasted under three conditions including hot air, infrared (IR) and microwave methods. Then, 80 pistachio kernels were analyzed by ultra high performance liquid chromatography. The results showed that all samples contained different ranges of acrylamide between 57 0.86 and 851 2.8 mg/kg. Besides, raw pistachios and sun dried pistachios also contained acrylamide, with the amount of 57 0.86 and 93 1.07 mg/kg, respectively. The highest acrylamide amount was found in raw pistachio (unsalted) roasted by IR method, while lower acrylamide amount observed in the microwave method. The amount of acrylamide in salted and roasted pistachios was less than just roasted pistachios under the same conditions. Finally, in all the treatments, increasing temperature, time, voltage, and power lead to an increase in acrylamide levels. The results showed that acrylamide in the roasted pistachios may cause health problems. This study presents a novel investigation in the effects of roasting conditions (temperature, power, voltage, and time) on acrylamide content in pistachios.