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1、华南农业大学综合实验报告实验项目名称：白酒品质的分析实验项目性质：综合实验计 划 学 时 ：所属课程名称：食品与发酵工业分析实验完成时间：白酒品质的测定1 原理1.1 测酸原理酸碱中和：R-COOH+NaoH R-COONa+H2O1.2 测酯的原理碱性加热的条件下，酯水解成酸和醇，使生成的酸与足量的已知的NaoH反应，再用已知浓度的H2SO4中和过量的碱，可以算出水解生成酸的量，进而得出酯的量。1.3 甲醇含量测定原理甲醇经氧化后形成甲醛，甲醛与品红亚硫酸作用生成紫蓝色的化合物与标准曲线比较定量。1.4 固形物的测定原理白酒经蒸发烘干后，不挥发物质残留于皿中，用称量法测定。1.5 酒精度的测
2、定原理用精密酒精计读取酒精体积分数示值，按附录B进行温度校正，求得在20oC时乙醇含量的体积分数，即为酒精度。2 仪器与试剂2.1 仪器分光光度计 恒温水槽，比色管 电热干燥箱 分析天平 瓷蒸发皿：100ml 干燥器（用变色硅胶作干燥剂）精密酒精计：分度值为0.1%vol2.2 试剂0.1MH2SO4 0.1MNaoH 高锰酸钾-磷酸 无甲醇的乙醇 甲醇标准使用液 草酸-硫酸 品红-亚硫酸3实验步骤3.1 总酸总酯步骤3.11吸取酒样50.0ml于250ml具塞锥形瓶中，加入酚酞2滴，用0.1M的NaoH滴定至粉红色（最后一滴时刚好变色），记下NaoH体积（总酸）3.12 再向第一步中的溶液中
3、加入0.1M的NaoH25ml，摇匀，沸水中回流0.5h。冷却至室温。（酯水解产生酸并与NaoH反应）3.13 0.1M的H2SO4中和过量的NaoH，记录H2SO4体积3.2 甲醇含量测定步骤3.21 标准曲线的制备3.22分析吸取0.00，0.10，0.20,0.40,0.60,0.80,1.00ml甲醇标准使用液于25ml具塞比色管中，并加入0.5ml无甲醇的乙醇，再加水至5.0ml。3.23 各加入高锰酸钾-磷酸2ml，混匀，放置10min，加入草酸-硫酸2ml，混匀，褪色，加品红-亚硫酸5ml，混匀，于30oC中水浴30min,比色分析制曲线。3.24 样品的处理取1.0ml待测样品
4、（白酒）于25ml具塞的比色管中，加水至5ml，其余操作同上。3.3 固形物的测定步骤3.31 吸取样品50ml，于已烘干到恒重的100ml蒸发皿中，置于电磁炉中小火蒸干，将蒸发皿放入103oC电热干燥箱内烘2h，取出置于干燥器30min，冷却，称重，再放入103oC电热干燥箱内，烘1h,取出置于干燥器30min，重复操作至恒重。3.4 酒精度测定步骤3.41 将试样（白酒）液注入洁净，干燥的100ml量筒中，静置数分钟，带酒中气泡消失后，放入洁净，擦干的酒精计，再轻轻按一下，不应接触量筒壁，同时插入温度计，平衡约5min，水平观察，读取与弯月面相切处的刻度值，同时记录温度，根据测得的酒精计示
5、值和温度，查附录B，换算的20oC时样品的酒精度。所得结果应表示至一位小数4 实验数据记录4.1 总酸表1 滴定白酒中的总酸时消耗的NaoH的量初读数（ml)末读数（ml)消耗体积（ml)NaoH体积1922.23.24.2 总酯表2 滴定剩余NaoH时所用的H2SO4的量初读数（ml)末读数（ml)消耗体积（ml)H2SO4体积3.615.511.94.3 甲醇表3 不同量的标准甲醇对应的吸光值甲醇含量0.00 0.10 0.20 0.40 0.60 0.80 1.00 待测样品OD值0.000 0.0340.0570.332 0.306 0.626 0.804 -0.016图1 甲醇的标准
6、曲线4.4 固形物表4 干燥后蒸发皿的质量蒸发皿净质量mo(g)第1次称重m(g)第2次称重m(g)56.603756.6140 56.6139 4.5 酒精度表5 酒精度测量数据与换算结果酒精度计读数温度计读数（oC）2926.029.826.0平均29.426.0换算成20oC酒精的浓度（用容量百分数表示)浓度温度白酒27.1%20oC5 实验结果的计算5.1 总酸由表可知：v1=3.2ml所以：式中：x1：酒中酸的含量（以乙酸计）g/L C1:0.1mol/L V1:NaoH的体积 0.061:10-3MNaoH对应的乙酸的质量5.2 总酯由表2可知：v2=11.9ml 所以：式中：x2
7、:总值量（以乙酸乙酯计）g/L C1:0.1mol/L C2:0.1mol/L V2:消耗的H2SO4的体积 0.088：与10-3MNaoH对应的乙酸乙酯的质量5.3 甲醇由图1可知 把代入上式得 （该x代表下式中的m) 所以，也即白酒样品中近似没有甲醇。式中：X： 待测样品中甲醇的含量g/100ml M： 待测样品中甲醇的质量（mg) V： 待测样品的体积（ml） 计算结果保留2位有效数字5.4 固形物计算公式：（结果至少保留两位有效数字）所以：式中：X:样品中的固形物的质量浓度，单位为每(g/L)m :固形物和蒸发皿的质量，单位为克（g);m0:蒸发皿的质量，单位为克（g)50.0：吸取
8、样品的体积，单位为毫升（ml)5.5 酒精度根据表5以及酒精度附表：酒精计温度浓度换算表截图换算得在20oC时，酒精度浓度为27.1%。6 结果的分析与讨论6.1总酸我们组的实验结果偏高；原因是：在用0.1M的NaoH滴定白酒中的总酸时，滴入的NaoH有少许过量，而并不是使酚酞刚刚变红色，所以结果算出来的总酸略有偏高。6.2 总酯由于测酸时加入的NaoH略偏高，所以造成用H2SO4进行反滴定时，消耗的H2SO4的体积也偏高，所以，求得的总酯的含量略偏低。6.3 甲醇由甲醇的标准曲线图可知该标准曲线的相关性不是很好，可能的原因是我们在进行吸光度的测定时没有对比色管内的一系列溶液摇匀，从而使吸光值
9、的测量误差较大，不过该标准曲线对样品中的甲醇含量的计算没有影响，因为白酒样品中含有甲醇的量非常微小，可以近似为零。讨论： 白酒中的其他醛类以及经高锰酸钾氧化后由醇类变成醛类，与品红亚硫酸作用也显色，但在一定浓度的硫酸酸性溶液中，除甲醛可以形成经久不褪色的紫色外，其他醛类历时不久即行消退或不显色，故无干扰。因此操作中条件必须严格控制。 当实验加入草酸硫酸溶液褪色放出热量，温度升高，此时需适当的冷却，才能加入亚硫酸品红溶液。亚硫酸品红显色时，温度最好控制在20oC，温度越低，所需显色时间越长，温度越高所需显色时间越短，但显色的稳定段也短。另外标准管和试样管显色温度之差不应超过1oC，因为温度对吸光
10、度有影响。6.4 固形物在实验的操作中，我们小组严格操作，实验过程没有明显的失误，忽略仪器误差，实验结果可靠。在实验中，对实验结果的影响因素有： 蒸发皿的洗涤是一项很重要的操作。蒸发皿洗得是否合格，会直接影响固形物分析结果的可靠性与准确度。选择合适的刷子，蘸水（或根据情况使用洗涤剂）刷洗，洗去灰尘和可溶性物质，用洁净的摄子夹住蒸发皿，先反复刷洗，然后边刷边用自来水冲洗，当倾去自来水后，达到蒸发皿上不挂水珠，则用少量蒸馏水或去离子水分多次（最少三次）冲洗，洗去所沾的自来水，干燥后使用。 分析天平是准确称量物质必不可少的仪器。称量前要校准天平，检查天平秤盘是否干净，称量速度要快、稳。 电热恒温箱内
11、要保持整洁，蒸发皿放入烘箱内，不要和试剂同时烘，否则可能延长烘干时间，甚至引起样品变化。 电热恒温箱温度控制在恒温1032，可防止因温度偏低而使固形物偏高，温度偏高使固形物偏低，同时也保证了检测结果的平行性及恒重的要求。 蒸发皿取出置于干燥器内冷却时，干燥器内变色硅胶要呈天蓝色，磁板要无灰尘。 在检测固形物的操作过程中，操作者在取用蒸发皿时，一定要使用摄子，且忌用手直接拿取，而影响固形物的检测结果。 附表 酒精计温度浓度换算表截图溶液温度酒 精 计 示 值3029.52928.52827.52726.52625.5温度20时用容量百分数表示乙醇浓度3524.223.723.222.822.32
12、1.821.320.820.420.03424.524.023.523.122.722.221.721.220.820.43324.924.423.923.523.122.622.021.621.220.83225.324.824.323.823.422.922.422.021.621.23125.725.224.724.223.823.322.822.421.921.43026.125.625.124.624.223.723.222.822.321.92926.426.025.525.024.624.123.623.222.722.22826.826.425.925.424.924.424.
13、023.523.022.62727.226.726.325.825.324.824.423.923.422.92627.627.126.626.225.725.224.724.223.823.32528.027.527.026.626.125.625.124.624.123.72428.427.927.426.926.426.025.525.024.524.02328.828.327.827.226.826.325.825.4 24.924.42229.228.728.227.727.226.726.225.825.324.82129.629.128.628.127.627.126.626.1
14、25.625.12030.029.529.028.528.027.527.026.526.025.51930.429.929.428.928.427.927.426.926.425.91830.830.329.829.328.828.327.927.2 26.726.21731.230.730.229.729.228.628.127.627.126.61631.631.130.630.129.529.028.528.027.527.01532.031.531.030.529.929.528.928.427.927.41432.431.931.430.930.429.929.328.828.32
15、7.81332.832.331.831.230.830.329.729.228.728.21233.332.832.231.631.230.730.229.629.128.51133.733.232.732.031.631.130.630.029.528.91030.133.633.132.532.031.531.030.429.929.3溶液温度酒 精 计 示 值2524.52423.52322.52221.52120.5温度20时用容量百分数表示乙醇浓度3519.619.218.818.417.917.416.916.416.015.63420.019.619.118.618.217.71
16、7.216.816.416.03320.319.819.419.018.618.117.617.216.716.23220.720.219.819.418.918.417.917.417.016.63121.020.620.219.819.318.818.317.817.417.03021.420.920.520.019.619.118.618.217.717.32921.821.320.820.419.919.419.018.518.017.62822.121.621.220.720.219.819.318.818.417.92722.522.021.521.020.620.119.619.
17、218.718.22622.822.421.921.420.920.520.019.519.018.62523.222.722.221.821.320.820.319.819.418.92423.523.122.622.121.6 21.120.720.219.719.22323.923.422.922.422.021.521.020.520.019.52224.323.823.322.822.321.821.320.820.419.92124.624.123.623.122.622.221.721.220.720.22025.024.524.023.523.022.522.021.521.0
18、20.51925.424.824.423.823.322.822.321.821.320.81825.725.224.724.223.723.222.622.121.621.11726.1 25.625.124.5 24.0 23.523.022.522.021.41626.525.925.424.924.423.823.322.822.321.81526.826.325.825.324.724.223.723.122.622.11427.226.726.225.625.124.624.023.523.022.41327.627.126.526.025.424.924.423.823.322.
19、71228.027.426.926.425.825.324.724.223.623.01128.427.827.326.726.225.625.024.523.923.41028.828.227.727.126.626.025.424.824.323.7Opinions and suggestions on the partys mass line educational practiceAccording to the central and provincial, municipal unified deployment, according to municipal Party comm
20、ittee about carrying out the partys mass line educational practice activity in the citys implementation opinions, the spirit of the partys mass line educational practice activities from 20* in January to 99 months, carried out at all levels of departments and directly affiliated institutions and gra
21、ss-roots party organizations. According to my actual County, the county to carry out the education practice put forward the following implementation opinions.First, the overall requirementsCounty county education practice to the eighteen Party of eight, the spirit of the the third Plenary Session of
22、 the 18th CPC Central Committee as the guidance, conscientiously implement the spirit of general secretary Xi Jinping book series of important speech, earnestly implement the Central Committee really, opinions and advice , party implementing the guiding ideology of opinions to determine the objectiv
23、es and requirements, step method, in accordance with the look in the mirror, dress up, wash bath, cure treatment, the general requirements of for the people pragmatic honest people as the theme, in carrying forward the spirit of Zhuanglang Zhuang, improve their work style, service to the masses of t
24、he people, the foundation of consolidating grassroots, promote transformation across efforts, to further implement the central eight regulations and The opposition party and government austerity waste regulations , double section provincial regulations, municipal provisions of the twelve plan and th
25、e implementation measures for on improving the work style of close ties with the masses law, highlight style building, carry out the whole wind spirit, resolutely oppose formalism, bureaucracy, hedonism and wasteful extravagance to solve the problems, Party members and cadres of the style and the ma
26、sses of people strong, the Ministry of Party members and cadres to further improve their thinking and understanding, to further change the style of the wind, the masses to close, honest and pragmatic people honest image to further establish the foundation to further reinforce the basic level. Style
27、of the building of the new results to promote the construction of a powerful force of the county and the ecological culture of the county and county construction.In educational practice activities of the unit is mainly: the county and below county departments under the organs, enterprises and instit
28、utions directly under the township, street, and community, village, non-public economic organizations, social organizations and other grass-roots organizations. Agencies and branches, each single unit, follow the rules on internal institutions. Educational practice with step by step.To adhere to the
29、 county leadership, leadership and leading cadres to focus on outstanding catch to directly contact the service of the masses of law supervision departments and window units, service industry, educational practice, pay attention to grasp the heavy towns, streets and villages, community education act
30、ivities and the masses of grassroots groups in close contact to strengthen, and the majority of Party members, cadres and the mass line line Marx doctrine view of the masses and the partys education.Always speak seriously as a basic attitude, adhere to positive education, to carry out criticism and
31、self criticism group, adhere to the pragmatic, more emphasis on leadership, pay more attention to the layers of the demonstration, more focus on the four winds, solve the problem, pay more attention to open the door, the participation of the masses, pay more attention to the classification guidance.
32、 Orderly, pay more attention to the cooperation and cohesion driven, more strict requirements on injection, really supervision practice, ensure education practice is not empty is not empty is not partial, not as a mere formality.Two, the key point of the taskThe main task of the countys education pr
33、actice is to seize against four wind this focus on centralized solve outstanding problems asked County, township leadership and leading cadres of the four winds, the disadvantages of the style, scale behavior to a large scale investigation, overhaul, cleaning greatly. At the same time, respond to th
34、e concerns of the masses, safeguard the interests of the masses, pay attention to solve practical problems, solve the people around the unwholesome tendencies especially on eat, take the card, Yong lazy luxury, extravagance and waste fees, privileges and other issues, timely and effective, without a
35、ny discount to solve, to improve the style of real implementation of the requirements of real to the grassroots, real let group Benefit the public.(a) focus on solving the four winds outstanding issuesThe central and provincial requirements, the county leadership and leading cadres of key performanc
36、e concept is not correct, do not dare to play, to engage in image project, political project, a leadership guide, a set of ideas, orders and prohibitions, and a policy, there are countermeasures county. The units directly under the heavy focus on solving Yung lazy drag, buck passing skin, work is no
37、t implemented, the service is not active. The dynamic problem of law enforcement and supervision departments and window units, service industry mainly solve the door hard, ugly face, something difficult, and arbitrary charges, fines, levies, and breach of privilege, chinakayao, not the problem of la
38、w. The township, street The collar of leading bodies and leading cadres to solve key does nottheir own conditions to develop the correct road, the maximum to avoid investment risk, gain profit.(three) vigorously promote the brand. To establish brand awareness, awareness of the use of brand, brand va
39、lue, brand acquisition performance, enhance the competitive strength. Concentrated manpower, careful planning, packaging and publicity of a number of unique, market influence and coverage of the brand, the implementation of key breakthroughs, to enhance the competitive strength, walking business roa
40、d the competition of alienation and characteristics, the pursuit of stability and development of the market.(four) to promote the integration of resources. To further broaden their horizons, effective integration of resources within the group, the city resources, other industries and regional resour
41、ces, mutual trust, mutual benefit, seeking win-win principle, in the framework of national policies and regulations, strict inspection and argumentation, legal consultation, examination and approval procedures, strict regulation of economic activities, attract injection the social investment to the
42、industry group, to achieve leveraging the development, ensure that the value of state-owned assets.(five) to strengthen the construction management personnel. Strengthen the management of education and training of cadres and workers of the existing business, firmly establish the concept of the marke
43、t, enhance the sense of crisis to adapt to market competition, the sense of urgency, improve the ability to respond to market competition, improve management and operation of the market. At the same time, according to the need of industrial development, vigorously the introduction of high-quality management management personnel, and strive to build a high-quality professional management team, hard work, and promote the entire workforce knowledge structure, age structure, structure optimization and upgrading ability, enhance core competitiveness, adapt to the need of market competiti