甲醛与NaOH对污泥EPS中蛋白质和多糖测定的影响

Influence of formaldehyde and NaOH on the analysis of proteins and polysaccharides in sludge EPS

甲醛-NaOH法广泛应用于污泥胞外多聚物（extracellular polymeric substance，EPS）的提取，但提取过程中残留的化学物质会干扰后续胞外多聚物组分的测定，通过改变甲醛用量和NaOH浓度研究了其对EPS中蛋白质和多糖测定的影响。结果表明：提高甲醛投加量和NaOH浓度，会降低蛋白质测定标线的线性、斜率及数据的精密度。但当甲醛投加量为12～20μL，NaOH浓度为1mol／L时，蛋白质标线的斜率和线性与不加甲醛和Na0H时相差不大，测试数据有较好的精密度。甲醛投加量与NaOH浓度对多糖测定几乎没有影响，因而在EPS提取之后不需要透析去除残留的甲醛，可直接进行测定。

The formaldehyde-NaOH method is widely used in extracellular polymeric substance （EPS） extraction from sludge, but the residual chemicals should be removed since they interfere with subsequent analyses. The influences of formaldehyde dosage and NaOH concentration on the analysis of proteins and polysaccharides for EPS extraction from sludge were investigated. The results show that for the protein analysis, the increased formaldehyde dosage and NaOH concentration increased the analysis uncertainty and reduced the linearity and slope of the standard curves. However, for formaldehyde dosages between 12 - 20 μL and NaOH concentration of 1 mol/L, the linearity and slope of the protein standard curves were similar to the blank. The polysaccharide analysis remained stable for the various formaldehyde dosages and NaOH concentration.