论文部分内容阅读
在酸性介质中,甲醛对溴酸钾氧化刚果红褪色反应有催化作用,而表面活性剂十二烷基磺酸钠对该褪色反应起到增敏作用,据此建立了一种高灵敏光度法测定痕量甲醛的新方法。在选定的条件下,甲醛浓度在0.02~1.0μg/m L范围内与刚果红褪色程度呈良好的线性关系,线性回归方程为ΔA=0.140 3C_(甲醛)+0.278 6,方法的检出限为6.2ng/m L,相对标准偏差为2.7%(C_(HCHO)=0.1μg/m L,n=8)。该法用于腐竹中痕量甲醛的测定,回收率在96.50%~109.0%之间。
In acidic medium, formaldehyde can catalyze the discoloration of Congo red by potassium bromate, and surfactant sodium dodecyl sulfate can sensitize the discoloration. Thus, a sensitive spectrophotometric method for the determination of trace A new method of formaldehyde. Under the selected conditions, the formaldehyde concentration showed a good linear relationship with the fading extent of Congo red in the range of 0.02-1.0 μg / mL, the linear regression equation was ΔA = 0.140 3C_ (formaldehyde) +0.278 6, and the detection limit Was 6.2 ng / m L with a relative standard deviation of 2.7% (C HCHO = 0.1 μg / m L, n = 8). The method was applied to the determination of trace amount of formaldehyde in yuba, the recovery was between 96.50% ~ 109.0%.