title: Determination of trace nickel in hydrogenated cottonseed oil by electrothermal atomic absorption spectrometry after microwave-assisted digestion.
abstract: Microwave digestion of hydrogenated cottonseed oil prior to trace nickel determination by electrothermal atomic absorption spectrometry (ETAAS) is proposed here for the first time. Currently, the methods outlined in U.S. Pharmacopeia 28 (USP28) or British Pharmacopeia (BP2003) are recommended as the official methods for analyzing nickel in hydrogenated cottonseed oil. With these methods the samples may be pre-treated by a silica or a platinum crucible. However, the samples were easily tarnished during sample pretreatment when using a silica crucible. In contrast, when using a platinum crucible, hydrogenated cottonseed oil acting as a reducing material may react with the platinum and destroy the crucible. The proposed microwave-assisted digestion avoided tarnishing of sample in the process of sample pretreatment and also reduced the cycle of analysis. The programs of microwave digestion and the parameters of ETAAS were optimized. The accuracy of the proposed method was investigated by analyzing real samples. The results were compared with the ones by pressurized-PTFE-bomb acid digestion and ones obtained by the U.S. Pharmacopeia 28 (USP28) method. The new method involves a relatively rapid matrix destruction technique compared with other present methods for the quantification of metals in oil.
authors: School of Materials and Chemical Engineering, Xi'an Technological University, Xi'an, China. gaizhang98@yahoo.cn
authors: Gai
authors: G
authors: Zhang
mesh_terms: D003369:Cottonseed Oil / Q000009:adverse effects / Q000737:chemistry* / Q000528:radiation effects; D004340:Drug Contamination; D055664:Electrochemical Techniques; D005503:Food Additives / Q000009:adverse effects / Q000737:chemistry* / Q000528:radiation effects; D005506:Food Contamination; D005511:Food Handling; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000737:chemistry; D006865:Hydrogenation; D006868:Hydrolysis / Q000187:drug effects / Q000528:radiation effects; D007202:Indicators and Reagents / Q000737:chemistry; D008872:Microwaves; D009532:Nickel / Q000032:analysis*; D017942:Nitric Acid / Q000737:chemistry; D010592:Pharmaceutic Aids / Q000009:adverse effects / Q000737:chemistry; D011138:Polytetrafluoroethylene / Q000737:chemistry; D015203:Reproducibility of Results; D013054:Spectrophotometry, Atomic; D013997:Time Factors
chemical_list: D003369:Cottonseed Oil; D005503:Food Additives; D007202:Indicators and Reagents; D010592:Pharmaceutic Aids; D017942:Nitric Acid; D009532:Nickel; D011138:Polytetrafluoroethylene; D006861:Hydrogen Peroxide