[Principal component analysis of mineral elements and fatty acids composition in flaxseed from ten different regions].

Flaxseed is a kind of biomass with high edible and medical value. It is rich in many kinds of nutrients and mineral elements. China is one of the important producing places of flaxseed. In order to explore the main characteristic constituents of mineral elements and fatty acids in flaxseed, the study of analyzing the mineral elements and fatty acid composition from 10 different regions was carried out. The contents of seventeen kinds of mineral elements in flaxseed were determined by inductively coupled plasma mass spectrometry (ICP-MS). The contents of fatty acids of the flaxseed oil obtained under the same conditions were determined by gas chromatography-mass spectrometer (GC-MS). The principal component analysis (PCA) method was applied to the study of analyzing the mineral elements and fatty acid compositions in flaxseeds. The difference in mineral elements and fatty acids of flaxseed from different regions were discussed. The main characteristic constituents of mineral elements and fatty acids were analyzed. The results showed that K, Sr, Mg, Ni, Co, Cr, Cd, Se, Zn and Cu were the main characteristic constituents of the mineral elements. At the same time, C16:0, C18:0, C18: 2, C18:3, C20:0 and C20:1 were the main characteristic constituents of the fatty acids. The combination of ICP-MS, GS-MS and PCA can reveal the characteristics and difference of mineral elements and fatty acids from different regions. The results would provide important theoretical basis for the reasonable and effective utilization of flaxseed.

[Culture medium based on biogas slurry and breeding of oil Chlorella].

The oil chlorella cultivation and biogas slurry treatment were combined. The biogas slurry provided water and nutrient for growing chlorella, at the same time, harmless treatment of biogas slurry was realized. This paper cultivated 4 species of oil chlorella in the mixed medium of biogas slurry and green algae medium (the volume ratios were 1 : 9, 1 : 3, 1 : 1 and 3 : 1, respectively), and compared their oil productivity to select the best oil chlorella species and the optimal culture medium. The results showed that, the combination of medium and chlorella species to reach the highest oil productivity was a volume ratio of 1 : 3 and the chlorella species BJ05, and the oil productivity of chlorella BJ05 was 9.20 mg x (L x d)(-1), higher than that in green algae medium [8.66 mg x (L x d)(-1)]. In mixed medium with a volume ratio of 1:3, the effect of adding different nutrients into the green algae medium on the oil productivity was examined, and the results showed that, sodium carbonate and citric acid had no negative effect on the oil productivity of chlorella BJ05. in the absence of sodium carbonate and citric acid, the oil productivity of chlorella BJ05 was 9.36 mg x (L x d)(-1), and the removal of COD (chemical oxygen demand), total nitrogen, total phosphorus and ammonia nitrogen rates were 59%, 75%, 61% and 100%, respectively. Deficiency in other nutrients had negative effect on the oil productivity. Therefore, the culture medium was further optimized to the mixed medium of biogas slurry and green algae medium with a volume ratio of 1 : 3 and without addition of sodium carbonate and citric acid.

[Determination and uncertainty evaluation of microelements in flaxseed by using ICP-MS under two modes].

Copper, iron, zinc and manganese in flaxseed were determined by inductively coupled plasma mass spectrometry (ICP-MS). After digestion by microwave-assisted, Cu, Fe, Zn and Mn were analyzed by using Standard and KED modes. In the present study, testing effectiveness of the two modes was compared. On this base, valid determination mode was selected for each of the elements and uncertainty evaluations of the four microelements were explored. According to JJF1059-1999 (Evaluation and Expression of Uncertainty in Measurement), the main influence factors were analyzed one by one. Each of the uncertainties was calculated separately. It was showed that the results of Cu, Fe, Zn and Mn in flaxseed determined by ICP-MS method were satisfactory. At the same time, the results obtained in this work were considered to be valuable as a reference for the evaluation of uncertainty in measurement of Fe, Cu, Zn and Mn with ICP-MS.