煤焦油沥青制备中间相

煤焦油沥青在微型高压釜中、氮气氛下,通过改变反应温度和停留时间,制取了中间相沥青(MP)。采用FTIR、偏光显微镜、XRD和SEM对MP进行了表征,表明煤焦油沥青经脱氢缩合反应转变成MP。其最佳反应条件为400℃、7h。     

Studies on contamination level of aflatoxins in some dried fruits and nuts of Pakistan

The occurrence of aflatoxins in dried fruits and nuts was surveyed in this study. One hundred and eighty samples of dried fruits and nuts were purchased from retail shops and local markets of different locations of NWFP and Northern areas of Pakistan. The samples were analyzed for total aflatoxins by immune affinity (IAC) clean-up with liquid chromatography and fluorescence detection. The results showed the percentage of contamination for total aflatoxins in the samples such as in; dried apricot (20%), dates (10%), dried figs (50%), dried mulberries (26%) and raisins (20%), while in apricot kernels (26%), almonds without shell (30%), walnuts with shell (40%), walnuts without shell (70%), peanut with shell (40%), peanuts without shell (50%), pistachios with shell (20%), pistachios without shell (50%) and pine nuts with shell (20%). The highest contamination levels of aflatoxins were found in one peanut sample (14.5 μg/kg) and one pistachio sample (14 μg/kg). Among all the contaminated samples, one dried apricot, three dried fig, one raisins, one apricot kernels, two walnuts with shell, three walnuts without shell, one peanuts with shell, two peanuts without shell and two pistachios without shell samples were above the suggested limit for total aflatoxins (4 μg/kg), set by EU regulations.     

Electrolytic recovery of chromium salts from tannery wastewater

Tannery wastewater collected from a local leather industry in Peshawar, Pakistan was subjected to DC electrolysis in a simple cell having two static sheet electrodes and stirring assembly after proper dilution and adjustment to desired conditions. One percent HNO(3) and 1% NaHCO(3) were used as electrolytes and pH adjusters. The latter salt also worked as sodium source for anodic deposition of Na(2)Cr(2)O(7). Various combinations of electrodes were tested and conditions optimized for best electrode couple with increased recovery and removal of chromium in the form of Cr(OH)(3) and/or Na(2)Cr(2)O(7) at cathode and anode, respectively. The recovery of 99% chromium was achieved after 2h electrolysis at a cell potential of 1.0 V, pH 5.0 and stirring rate of 500 rpm using Pb sheet as anode and Cu sheet as cathode. The most interesting and novel finding of this work was the recovery of the mentioned salt(s) alone at Cu cathode or Pb anode or collectively at both electrodes by proper control of pH. Such treatment not only minimizes the environmental water pollution, but results in the formation of useful products employed for recycling purpose in tannery or other related industry to make the process economical.     

Studies on contamination level of aflatoxins in some cereals and beans of Pakistan

The occurrence of aflatoxins in some cereals and beans was surveyed in this study. One hundred and sixty samples of cereals and beans were purchased from retail shops and local markets of different locations in Pakistan. The samples were analyzed for total aflatoxins to using immune affinity (IAC) clean up with liquid chromatography and fluorescence detection. The results showed the percentage of contamination for total aflatoxins in the samples such as in; rice (25%), broken rice (15%), wheat (20%), maize (40%) barley (20%) and sorghum (30%), while in red kidney beans (20%), split peas (27%), chick pea (10%), cow pea (20%), and soybean (15%). The highest contamination levels of aflatoxins were found in one wheat sample (15.5 μg/kg), one maize sample (13.0 μg/kg) and one barley sample (12.6 μg/kg). Among all the contaminated samples, two rice, one rice broken, two wheat, three maize, two barley, one sorghum, one red kidney beans, one split peas and two soybeans were above the suggested limit for total aflatoxins (4 μg/kg), set by EU regulations.