portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">应用于检测食品中的微量金属，也可用于检测食品中的非金属元素，如氯、磷等。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">常用的有portant; word-wrap: break-word !important;">干法灰化、湿法消化、微波消解三大类。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">原则是：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">方法简便，使用试剂越少越好；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">耗时短，有机物破坏的越彻底越好；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">被测元素不受损失；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">破坏后溶液容易处理，不影响以后的测定步骤。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">1.1 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">干法灰化portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">常见灼烧装置是灰化炉，即高温马弗炉。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">样品放入坩埚，小心炭化，portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">500~600portant; word-wrap: break-word !important; font-family: 宋体; color: red;">℃灼烧灰化portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">后，水分及挥发物质以气态逸出，样品中的碳、氢、氮与本身的氧及空气中的氧气生成portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">COportant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">2portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">、portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">Hportant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">2portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">Oportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">和氮的氧化物散失，最后留下无机物（无机灰分）。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">优点是有机物被破坏彻底，操作简单，使用试剂少，适用于大批量样品的分析测定。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">缺点是砷、汞、铅等金属容易在高温下挥发损失。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">对于难以灰化的样品，为了缩短灰化时间，促进灰化完全，可用灰化助剂。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">灰化助剂有两类：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">乙醇、硝酸、碳酸铵、过氧化氢，灼烧后完全消失，不增加残灰质量，可加速灰化。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">氧化镁、碳酸盐、硝酸盐，与灰分混杂，使碳粒不被覆盖，所以燃烧完全，应同时做空白试验。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">1.2 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">湿法消化portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">在强酸、强氧化剂并加热的条件下，有机质被分解，其中碳、氢、氮以portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">CO2portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">、portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">H2Oportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">和氮的氧化物等形式挥发逸出，无机盐和金属离子则留在溶液中。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">平板电炉portant; word-wrap: break-word !important; font-family: 宋体; color: red;">为消解装置，整个过程都在液体状态下加热进行，portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(154, 205, 50);">置于通风处portant; word-wrap: break-word !important; font-family: 宋体; color: red;">。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">所用的强氧化剂有：浓硫酸、浓硝酸、高氯酸、双氧水等，实际工作中一般使用混合氧化剂。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">优点是加热温度较干法低，减少了金属挥发逸散的损失。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">缺点是会产生大量有毒气体，操作需在通风柜中进行。耗用试剂较多。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">消化初期，产生大量泡沫，易冲出瓶颈，造成损失，需操作人员随时照管，操作中还应控制火力，注意防爆。必须做空白试验。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">1.3 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">微波消解portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">将样品置于密封的聚四氟乙烯消解管中，微波加热，完成有机质分解的工作。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">优点是样品portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(154, 205, 50);">全部消解不会造成元素损失portant; word-wrap: break-word !important; font-family: 宋体; color: red;">，试剂少，耗时短，portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">缺点是价格高，容量偏小，不宜处理高挥发性的物质（容易发生爆炸），必要时需进行加热预消解。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: red;">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-size: 18px;">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: purple;">二portant; word-wrap: break-word !important; font-family: 宋体; color: purple;">、蒸馏法portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: purple;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">定义：利用液体混合物中各组分挥发性的不同，分离出纯组分的方法。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">用于除去干扰组分，也可用于蒸馏分离出被测组分。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">常用蒸馏法有：portant; word-wrap: break-word !important;">常压蒸馏、减压蒸馏、水蒸气蒸馏。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">2.1 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">常压蒸馏portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">常压蒸馏portant; word-wrap: break-word !important; font-family: 宋体; color: red;">用于受热后不发生分解或沸点不太高的样品。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如二氧化硫。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">沸点不高于portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">90portant; word-wrap: break-word !important; font-family: 宋体; color: red;">℃可用水浴，如果沸点超过portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">90portant; word-wrap: break-word !important; font-family: 宋体; color: red;">℃，可改用油浴、沙浴、盐浴。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">蒸馏器要加石棉或棉垫保温。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如被蒸馏物不易爆炸或燃烧，可用酒精灯或电炉直接加热。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">2.2 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">减压蒸馏portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">减压蒸馏portant; word-wrap: break-word !important; font-family: 宋体; color: red;">用于常压下容易分解或沸点太高，或被蒸馏组分与水分形成共沸物不易蒸馏完全的样品。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: red;">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">2.3 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">水蒸气蒸馏portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">水蒸气蒸馏portant; word-wrap: break-word !important; font-family: 宋体; color: red;">适用于检测食品样品中的挥发性物质或低沸点物质。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如糕点中的丙酸和portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">N-portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">亚硝胺类。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-size: 18px;">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: purple;">三portant; word-wrap: break-word !important; font-family: 宋体; color: purple;">、溶剂提取法portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: purple;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">利用样品或试液中各组分对某种溶剂溶解度不同，加入某些溶剂，将欲分离组分完全或部分分离的方法。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">根据两相状态不同可分portant; word-wrap: break-word !important;">portant; word-wrap: break-word !important; font-family: 宋体;">固portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">-portant; word-wrap: break-word !important; font-family: 宋体;">液萃取法、液portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">-portant; word-wrap: break-word !important; font-family: 宋体;">液萃取法。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">3.1 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">固portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">-portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">液萃取法portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">用适当的溶剂将固体样品中的某组分萃取出来，又称浸提法。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">溶剂既要对被提取组分有很好的溶解度，又不与样品发生作用，同时沸点不应太高，否则不利于溶剂回收。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">常用的固portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">-portant; word-wrap: break-word !important; font-family: 宋体; color: red;">液萃取模式有：振荡萃取、匀浆萃取、索氏萃取器萃取、超声波萃取等。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">3.1.1 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">振荡萃取portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">均匀样品可直接加入溶剂，浸泡后在振荡器上振荡。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">非均匀样品可先加入适量蒸馏水匀浆后，再加入溶剂浸泡、振荡portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">30~60minportant; word-wrap: break-word !important; font-family: 宋体; color: red;">。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">振荡后过滤，残渣用溶剂洗涤，合并入萃取液。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">可用于提取六六六、滴滴涕。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
3.1.2 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">匀浆萃取portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">准确称取适量样品，加入一定体积溶剂，高速匀浆机快速捣碎制成匀浆，过滤。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">为萃取充分，滤渣可加溶剂重复萃取，合并萃取液。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如乙腈作为溶剂匀浆萃取果蔬中的农药组分。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
3.1.3 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">索氏萃取器portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">通过连续循环回流萃取，效率高，但时间较长portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如脂肪测定。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
3.1.4 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">超声波萃取portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">细微状态样品置于容器中，加入溶剂，将容器浸于超声波仪中，以超声波加速分析物的溶解和扩散，提高萃取效率。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">用于快速提取样品中的待测目标化合物。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">3.2 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">液portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">-portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">液萃取法portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">利用分析物与干扰物在两种不相容的溶剂中分配系数不同，使分析物从干扰物中分离，从而达到样品液的净化。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">通常将分析物分离到有机相，通过有机溶剂蒸发来浓缩分析物。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
3.2.1 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">溶剂的选择portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">与水互溶的有机溶剂，不适用液液萃取。如低分子量的醇、酮、醛、乙腈。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">采用单一纯溶剂提取多组分残留物的效果经常不理想，通常用非极性溶剂和极性溶剂组成一对溶剂来进行分配。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">常用溶剂对有丙酮portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">-portant; word-wrap: break-word !important; font-family: 宋体; color: red;">乙烷（石油醚）、portant; word-wrap: break-word !important; font-family: 宋体; color: red;">环己烷portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">-portant; word-wrap: break-word !important; font-family: 宋体; color: red;">乙酸乙酯。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">选择溶剂应符合portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">“portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">相似相溶portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">”portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">原则，溶剂的极性越接近分析物的极性，萃取效率越高。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">常用溶剂的极性大小顺序为：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">水portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">乙腈portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">甲醇portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">乙酸乙醇portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">异丙醇portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">丙酮portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">四氢呋喃portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">乙酸乙酯portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">三氯甲烷portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">硝基甲烷portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">二氯甲烷portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">乙醚portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">苯portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">甲苯portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">四氯化碳portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">二硫化碳portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">环己烷portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">>portant; word-wrap: break-word !important; font-family: 宋体; color: red;">正己烷portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">3.2.2 portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">pHportant; word-wrap: break-word !important; font-family: 宋体; color: red;">的影响portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">影响有效萃取的最重要因素之一。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">脱氢乙酸portant; word-wrap: break-word !important; font-family: 宋体; color: red;">、苯甲酸、山梨酸等在酸性条件下会溶解在某些有机溶剂中，将样品portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">-portant; word-wrap: break-word !important; font-family: 宋体; color: red;">溶剂体系portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">pHportant; word-wrap: break-word !important; font-family: 宋体; color: red;">值调至碱性，化合物就会生成盐类分配到水相中。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">萃取出的碱性分析物可反萃取到酸性有机溶液中。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如气象色谱法测定脱氢乙酸、过氧化苯甲酰等。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
3.2.3 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">避免和破坏乳化的常用方法portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">急速振动样品使其在分液漏斗中发生完全的混合，是一个非常重要的操作。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">产生大量的界面区域，利于有效分配。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">由于物质剧烈振动，液液萃取中常发生乳化现象，尤其是含有表面活性剂和脂肪的样品，portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(154, 205, 50);">会影响被测组分数据的准确portant; word-wrap: break-word !important; font-family: 宋体; color: red;">。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">避免和破坏乳化的方法有：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">混合震摇时，轻缓的固定一个方向震摇；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">采用高速离心振荡或振荡后再用玻璃棉或滤纸过滤；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">加盐到水相，通常有portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">NaClportant; word-wrap: break-word !important; font-family: 宋体; color: red;">固体、portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">2%~5%NaClportant; word-wrap: break-word !important; font-family: 宋体; color: red;">溶液或portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">Na2SO4portant; word-wrap: break-word !important; font-family: 宋体; color: red;">溶液。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">加入少量另一种有机溶剂，如无水乙醇。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: red;">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-size: 18px;">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: purple;">四portant; word-wrap: break-word !important; font-family: 宋体; color: purple;">、样品的浓缩portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: purple;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">目的：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">从样品中萃取的分析物浓度如果在定量限之上，那么在色谱分析时将没有干扰，可直接进行测定。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">但当被测化合物的浓度较低时，需要在净化和测定前将萃取液浓缩。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">样品液的浓缩过程就是溶剂挥发的过程。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">将溶剂蒸发至近干即可，否则由于溶剂蒸干会导致分析物损失。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">常用浓缩方法：
portant; word-wrap: break-word !important;">portant; word-wrap: break-word !important;">4.1 portant; word-wrap: break-word !important;">自然挥发或氮气流下挥发portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">适用于小体积样品液和易挥发溶剂，可适当加热。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: red;">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">4.2 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">减压旋转蒸发portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">优点是温度低，浓缩速度快。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">但旋转蒸发过程中，水浴温度不宜过高，真空度不宜过低，否则溶剂蒸发过快易带走目标化合物。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-size: 18px;">portant; word-wrap: break-word !important; color: purple;">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">五portant; word-wrap: break-word !important; font-family: 宋体; color: purple;">、气相色谱化学衍生化portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: purple;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">利用化学反应使样品中目标分析物与衍生化试剂作用生成衍生物（portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(154, 205, 50);">改变样品化学性质portant; word-wrap: break-word !important; font-family: 宋体; color: red;">），使其适合于特定的分析方法。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">在气相色谱分析中，制备衍生物的目的是：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">解决原化合物不能直接进样分析的问题：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">某些物质挥发性过高或过低，难以汽化，或者极性太强或稳定性差，不能直接进样分析。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如：脂肪酸沸点高，难汽化，经甲酯化生成脂肪酸甲酯衍生物，易于气相色谱分析。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">通过制备衍生物对分析物进行分离和鉴定：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如：环己基氨基磺酸钠在酸性条件下与亚硝酸钠反应，生成特定的化合物，从而可用气相色谱法氢火焰离子化检测器进行定性定量测定。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">化合物通过特有试剂衍生化后进行检测：portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">化合物经特有试剂衍生后，可用选择性检测器进行分析，提高灵敏度及最低检测量。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">如：奶粉中的碘，在适当条件下，用丁酮衍生后，生成的碘丁酮可以用气相色谱电子捕获检测器进行测定。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: rgb(68, 68, 68);">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important;">portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif;">5.1 portant; word-wrap: break-word !important; font-family: 宋体;">衍生化方法的要求portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">反应容易重复，操作简单；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">反应能定量进行；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">衍生物易纯化；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">衍生物易于色谱分离和检测；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">没有或少有副反应，反应条件温和、产率高；portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">衍生物的沸点与原化合物的沸点相比至少差portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">10portant; word-wrap: break-word !important; font-family: 宋体; color: red;">℃。
portant; word-wrap: break-word !important; font-size: 16px;">portant; word-wrap: break-word !important; color: red;">portant; word-wrap: break-word !important; font-family: 宋体;">
portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">5.2 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">常见衍生化反应portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
5.2.1 portant; word-wrap: break-word !important; font-family: 宋体; color: red;">硅烷化反应portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: red;">三甲基硅烷portant; word-wrap: break-word !important; font-family: 宋体; color: red;">化应用较多。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: red;">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">含有羟基、羧基、巯基、氨基等官能团的化合物与硅烷化试剂反应后，官能团上的氢原子被烷基portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">-portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">硅基取代，生成极性低、挥发性高、热稳定性好的硅烷基化合物。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">硅烷化反应体系中不能含有水分，否则会导致衍生失败。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">选用溶剂一般为己烷、苯、吡啶、四氢呋喃、二甲基亚砜等非极性溶剂。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">制备衍生物时，将样品提取液挥发至干，加入硅烷化衍生试剂portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">50~100μLportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">，混匀后在portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">60~80portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">℃下加热portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">20~60minportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
5.2.2 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">酰化反应portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">官能团中活泼氢被酰基取代，生成极性低、挥发性高的衍生物。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">酰化反应可分为酸酐法和卤代酰基法。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">制备衍生物时，将样品提取液挥发至干，加入酰化衍生试剂portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">100μLportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">，再加portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">50μLportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">吡啶，混匀后在portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">60~80portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">℃下加热portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">20~30minportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
5.2.3 portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">酯化反应portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">特别适用于含羟基的脂肪酸、氨基酸、羧基酸、不饱和酸、多元酸、芳香酸、多环酸、无机酸等化合物的衍生化。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">通常有甲酯化、丁酯化、苄酯化。portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">
portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">制备衍生物时，将样品提取液挥发至干，加入酯化衍生试剂portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">100μLportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">，混匀后在portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">60portant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">℃加热portant; word-wrap: break-word !important; font-family: Tahoma, sans-serif; color: rgb(68, 68, 68);">20~30minportant; word-wrap: break-word !important; font-family: 宋体; color: rgb(68, 68, 68);">。
