In this study, the trace elements lead (Pb), arsenic (As), cadmium (Cd), nickel (Ni), copper (Cu), zinc (Zn) and iron (Fe) quantity have been investigated using graphite furnace atomic absorption ...spectrometry (GFAAS) and sulphur dioxide (SO
2
) residual by iodometric titration method in raisin samples in different regions of Iran. The results showed that the concentration of Cu, Zn and Fe were in the range of 0.053-0.212 mg/kg, 0.048-0.170 mg/kg and 0.541-0.843 mg/kg, respectively, whereas Cd, Ni, As and Pb concentrations in the samples were less than detection limit (LOD). The SO
2
residual in raisin samples was between 30 and 843.33 mg/kg. The LOD of Cu, Fe, Zn, Cd, Pb, Ni, and As were 0.022 mg/kg, 0.5 mg/kg, 0.047 mg/kg, 0.04 mg/kg, 0.019 mg/kg, 0.024 mg/kg and 0.05 mg/kg, respectively. The Monte Carlo simulation results showed that the indexes of target hazard quotient (THQ) due to ingestion of SO
2
residues estimated lower than the safe level (THQ < 1) in all samples, except in the Raisin-B and Raisin-D samples. Accordingly, to ensure consumer health and improve international trade, continuous control and adaptive regulation of sulphur dioxide residues and trace elements in dried fruit are recommended.
This paper describes the electrodeposition of polyphosphate-doped polypyrrole/nanosilica nanocomposite coating on steel wire for direct solid-phase microextraction of bisphenol A and five phthalates. ...We optimized influencing parameters on the extraction efficiency and morphology of the nanocomposite such as deposition potential, concentration of pyrrole and polyphosphate, deposition time and the nanosilica amount. Under the optimized conditions, characterization of the nanocomposite was investigated by scanning electron microscopy and Fourier transform infra-red spectroscopy. Also, the factors related to the solid-phase microextraction method including desorption temperature and time, extraction temperature and time, ionic strength and pH were studied in detail. Subsequently, the proposed method was validated by gas chromatography-mass spectrometry by thermal desorption and acceptable figures of merit were obtained. The linearity of the calibration curves was between 0.01 and 50 ng/mL with acceptable correlation coefficients (0.9956–0.9987) and limits of detection were in the range 0.002–0.01 ng/mL. Relative standard deviations in terms of intra-day and inter-day by five replicate analyses from aqueous solutions containing 0.1 ng/mL of target analytes were in the range 3.3%–5.4% and 5%–7.1%, respectively. Fiber-to-fiber reproducibilities were measured for three different fibers prepared in the same conditions and the results were between 7.3% and 9.8%. Also, extraction recoveries at two different concentrations were ≥96%. Finally, the suitability of the proposed method was demonstrated through its application to the analysis of some eye drops and injection solutions.
•A now nanocomposite made of polyphosphate-doped polypyrrole/nanosilica is prepared.•The nanocomposite were synthesized electrochemically on steel wire.•The extraction capability of bisphenol and phthalates were examined by the nanocomposite.•Some eye drops and injection solutions were tested as real samples.
Diazinon poisoning is an important issue in occupational, clinical, and forensic toxicology. While sensitive and specific enough to analyse diazinon in biological samples, current methods are ...time-consuming and too expensive for routine analysis. The aim of this study was therefore to design and validate a simple dispersive liquid-liquid microextraction (DLLME) for the preparation of urine samples to be analysed for diazinon with high performance liquid chromatography with diode-array detector (HPLC-DAD) to establish diazinon exposure and poisoning. To do that, we first identified critical parameters (type and volume of extraction and disperser solvents, pH, surfactant, and salt concentrations) in preliminary experiments and then used central composite design to determine the best experimental conditions for DLLME-HPLC-DAD. For DLLME they were 800 µL of methanol (disperser solvent) and 310 µL of toluene (extraction solvent) injected to the urine sample rapidly via a syringe. The sample was injected into a HPLC-DAD (C
column, 250×4.6 mm, 5 μm), and the mobile phase was a mixture of acetonitrile and buffer (63:37 v/v, pH 3.2; flow rate: 1 mL/ min). Standard calibration curves for diazinon were linear with the concentration range of 0.5–4 µg/mL, yielding a regression equation Y=0.254X+0.006 with a correlation coefficient of 0.993. The limit of detection and limit of quantification for diazinon were 0.15 µg/mL and 0.45 µg/mL, respectively. The proposed method was accurate, precise, sensitive, and linear over a wide range of diazinon concentrations in urine samples. This method can be employed for diazinon analysis in routine clinical and forensic toxicology settings.
In this work polylactic acid (PLA)/starch biocomposite samples with optimized mechanical properties and suitable cost have been prepared by extrusion and thermal mixing. The variables to be optimized ...were PLA, corn starch, ethyl vinyl acetate (EVA), carboxy methyl cellulous (CMC) and glycerol mono- stearate (GMS) contents. The experiments were carried out based on the experimental design using D-optimal mixture methods. The analysis of variance indicated accuracy of the model. It was observed that biocomposite sample with PLA 59.5%, Starch 20%, EVA 10%, CMC 6.5%, GMS 2% and CaCO
3
2% would be attained noticeable improvement in the mechanical properties. Fourier transform infrared spectroscopy (FTIR) in combination with partial least square (PLS) chemometric technique was used to estimate the mechanical properties in five different spectral regions. Results show good accuracy between calibration and validation sets also denoted that O-C = O stretching and C = O stretching functional groups of PLA, EVA, CMC and GMS have the most positive effect on tensile strength and hydrogen bonded hydroxyl group of starch has the minimum positive effect. This research provided a method to improve the mechanical properties of biocomposite samples by using the D-optimal design and PLS chemometric techniques and Obtained results demonstrated that PLS could accurately predict mechanical properties in these spectral regions.
Fourier transform infrared spectroscopy coupled with chemometrics was employed to detect packaging polylactic acid-based biocomposite samples adulterated with polypropylene (PP) 30–45% and linear ...low-density polyethylene 2–10%. Principal component analysis, soft independent modeling of class analogy (SIMCA) and partial least square discriminate analysis (PLS-DA) chemometric techniques were utilized to classify samples in different classes. Totally, 362 samples were modeled in three different classes (two adulterated and one non-adulterated). The obtained results revealed that PLS-DA is the most suitable chemometric approach for prediction of probable adulteration in biocomposite samples with reliable specificity and selectivity. It could provide 99% correct class prediction rate between non-adulterated biocomposite samples and adulterated ones, while SIMCA methods provided 73.33% prediction accuracy in classification.
In Rosmarinic Acid (RA) is a phenolic acid which has many biological activities such as antioxidant, anti inflammatory and anti viral effects. In the present study, we have studied the anti Herpes ...simplex type 1 (HSV-1) effect of methanolic extract of Zataria multiflora which has been standardized on the basis of RA content. Methanolic extract of Zatria multiflora was prepared by maceration method. RA content of plant extract was measured by spectrophotometry method using the calibration curve of RA. Maximum non Toxic Concentration (MNTC) of the plant was determined by neutral red method. MNTC and lower serial dilutions of extract were examined in vitro on vero cells for their effect against HSV-1 using a plaque reduction assay. Acyclovir was used as positive control. Time-dependent antiviral effect of Z. multiflora was studied by adding the extract to HSV-1 infected vero cells at different stages of infection. The percentage of RA was determined as 2.2% in Z. multiflora. This plant was effective in all used concentrations and significantly reduced plaque formation up to 100% at concentrations of 800 and 1000 microg mL(-1). Clearly Z. multiflora revealed both a time and concentration inhibition. It seems that the presence of rosmarinic acid would be a determining factor for anti HSV activity of Z. multiflora.
Trovanje diazinonom važan je problem za medicinu rada te kliničku i forenzičnu toksikološku praksu. Premda su postojeće metode njegova utvrđivanja u biološkim uzorcima dovoljno osjetljive i ...specifične, njihova je primjena za rutinske analize preskupa i dugotrajna. Zbog toga je cilj ovoga istraživanja bio razviti i validirati jednostavnu metodu disperzivne tekućinsko-tekućinske mikroekstrakcije (engl. dispersive liquid-liquid microextraction, krat. DLLME) kojom bi se uzorci ljudske mokraće pripremili za analizu diazinona tekućinskom kromatografijom visoke djelotvornosti s detektorom s nizom fotodioda (engl. high performance liquid chromatography with diode-array detector, krat. HPLC-DAD) radi utvrđivanja izloženosti i trovanja diazinonom. U tu smo svrhu u preliminarnim eksperimentima prvo odredili ključne parametre: vrstu i volumen ekstrakcijskoga i disperzijskoga otapala, pH, površinski aktivne tvari (surfaktanta) te koncentraciju soli. Zatim smo s pomoću eksperimentalnoga centralnoga kompozitnoga dizajna utvrdili optimalne eksperimentalne uvjete za DLLME-HPLC-DAD. Za DLLME oni su bili 800 μL metanola (kao disperzijskoga otapala) te 310 μL toluena (kao ekstrakcijskoga otapala) za brzu injekciju uzorka mokraće. Uzorak je injektiran u HPLC-DAD (5-mikrometarski analitički stupac C18, 250×4,6 mm), a mobilna je faza bila mješavina acetonitrila i pufera (63:37 v/v, pH 3.2; protok: 1 mL/min). Standardne su kalibracijske krivulje za diazinon bile linearne s rasponom koncentracija diazinona od 0,5 do 4 μg/mL, a regresijska jednadžba Y=0,254X+0,006 s koeficijentom korelacije 0,993. Granice detekcije odnosno kvantifikacije diazinona bile su 0,15 μg/mL odnosno 0,45 μg/mL. Ova se metoda pokazala točnom, preciznom, osjetljivom i linearnom u širokom rasponu koncentracija diazinona u uzorcima mokraće, stoga se može koristiti za njegovu rutinsku analizu u kliničkoj i forenzičnoj toksikološkoj praksi.
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