摘要:本文采用分光光度法研究了乙酰丙酮与甲醛的显色反应(pH 5.5-7.0),并确定了最佳试验条件,提出一个灵敏度高,简便、快捷测定甲醛含量的分光光度法。结果表明:在pH 5-7的条件下,此时最大吸收波长位于412 nm处,最佳显色时间为3 min。得到标准曲线为 Y=0.15672X+0.00323,R2=0.99484.Y是吸光度,X是甲醛的浓度。并得出检出限为0.25 mg/L。样品预处理:称取适量样品打碎于250 ml蒸馏烧瓶中,加入2.5 ml液体石蜡和10 ml 10%磷酸,浸泡1小时,加入沸石,在120 ℃进行蒸馏,收集馏液80-90 ml,移入100 ml容量瓶,定容。这个方法可以对海产品中的甲醛含量进行测定,并且得到满意的结果。48216
毕业论文关键词:分光光度法;乙酰丙酮;甲醛;海产品
The analysis of the formaldehyde content in seafood in Vegetable market
Abstract: This article makes use of the spectrophotometric method to research the color reaction on the acetyl acetone and formaldehyde(pH = 5.5-7.0). Thus the best experiment conditions were concluded, which will be a high sensitivity, simple and fast spectrophotometric method of formaldehyde content testing.Results show that on the condition of potential of hydrogen of acetic acid is 5 to 7,the maximum absorption wavelength is located at 412 nm, the best time for 3 minutes.The standard curve is: Y = 0.15672X+0.00323, the correlation coefficient is: R2 = 0.99484.Y is absorbance ,X is formaldehyde content.And the detection limit was 0.25 mg/L.Sample pretreatment:Take an appropriate amount of sample broken on 250 ml distillation flask, adding liquid paraffin and 10 2.5ml ml 10% phosphate,Soak for 1 hours,Adding zeolite,Distillation at 120℃,Collect distillate 80-90 ml,Moving into 100 ml volumetric flask,constant volume。This method can be used for the testing of formaldehyde content in seafood, and we come off Satisfactory results.
KeyWords:formaldehyde; spectrophotometric method; Acetyl acetone ; seafood
目录
1前言 1
1.1海产品中甲醛含量分析的重要意义 1
1.2甲醛含量分析方法的介绍 2
1.2.1分光光度法 2
1.2.2高效液相色谱法 2
1.2.3气相色谱法 2
1.2.4示波极谱法 3
1.3分光光度法的原理 3
1.4分光光度法的分类 4
1.4.1乙酰丙酮分光光度法 4
1.4.2变色酸分光光度法 4
1.4.3副品红法 5
1.4.4催化光度法 5
1.4.5 AHMT分光光度 6
2.实验内容 6
2.1 试剂与材料 6
2.2 实验仪器 6
2.3 实验方法 7
2.3.1 工作曲线的绘制 7
2.3.2 未知样品的测定 10
3 结果与讨论 11
3.1 最大吸收波长的确定 11
3.2 最优显色时间的确定 11
3.3 检出限的测定 12
3.4甲醛含量的测定 13
3.4.1 工作曲线的绘制 13