乙腈

Methods Protein in blood and urine was precipitated directly by acetonitrile with acetanilide was used as the internal standard using Agilent Zorbax SB-Aq column (250 mm×4.6 mm, 5 μm). The mixed solvents of water (triethylamine 0.12%, acetic acid 0.12%) and acetonitrile were used as the mobile phase to separate cephalosporins using gradient elution method at 1 mL/min and 254 nm.

以乙酰苯胺为内标，血液和尿液用乙腈直接沉淀蛋白，采用Agilent Zorbax SB-Aq(250 mm×4.6 mm， 5 μm)色谱柱，流动相选用水（含0.12%三乙胺和0.12%乙酸）和乙腈的混合溶剂梯度洗脱，流速1 mL/min，检测波长254 nm。

A comparison of using two different nitriles, acetonitrile and benzonitrile, shows that benzonitrile gives higher conversion.

通过以乙腈和苯甲腈分别作为反应用腈的对比实验发现，苯甲腈的效果优于乙腈。

Benzene nitriles studied included parent benzene nitriles(cinnamonitrile,benzo nitrile,benzeneacetonitrile,isopropyl benzeneacetonitrile) and para-chloro ben zene nitriles(para-chloro cinnamonitrile,para-chloro benzonitrile,para-chloro be nzeneacetonitrile,para-chloroisopropyl benzeneacetonitrile).

所研究的苯腈类化合物包括苯腈类母体化合物(苯丙烯腈、苯甲腈、苯乙腈、异丙基苯乙腈)和对氯苯腈类化合物(对氯苯丙烯腈、对氯苯甲腈、对氯苯乙腈、对氯异丙基苯乙腈)。

Has established the Avey rhzomorph through the field test remains the analysis method in the sea cabbage and the soil, and remained to it in the sea cabbage and the soil has carried on the determination, the sample with the methyl cyanide extraction, after extracting the revolving concentration nearly did, with the few methyl cyanides dissolves, passed through PRS the solid phase extract column to purify again, eluent air-dried after the nitrogen with the nitrogen methyl imidazole and the trifluoroacetic acid bitter wine grows, the derivative with the highly effective liquid chromatography analysis, used the external standard legal quantity.

通过田间试验建立了阿维菌素在甘蓝及土壤中的残留分析方法，并对其在甘蓝和土壤中的残留进行了测定，样品用乙腈提取，提取液旋转浓缩近干后用少量乙腈溶解，再经PRS固相萃取柱净化，洗脱液经氮气吹干后用氮甲基咪唑和三氟乙酸酐衍生，衍生物用高效液相色谱分析，采用外标法定量。

After centrifugation, the extracts were separated on HILIC column by using acetonitrile-water as mobile phase. The analytes were identified and quantitated by LC-tandem MS under the positive/negative electrospray ionization and multiple reaction monitormode. The calibration curves showed good linearity in the range of 25-5000 μg/kg for melamine and cyanuric acid, and 50-10000 μg/kg for ammeline and ammelide. The limits of detection and limits of quantification were in the range of 5-20 μg/kg and 50-100 μg/kg, respectively.

牛奶样品直接用乙腈超声波提取；奶粉样品先用水溶解后再加乙腈超声波提取，高速离心后以乙腈－水为流动相，采用亲水作用色谱柱分离这4种化合物，在电喷雾正、负电离切换多反应监测模式下进行定性与定量分析，三聚氰酸一酰胺与三聚氰酸二酰胺含量在50~10000μg/kg之间、三聚氰胺与三聚氰酸在25~5000μg/kg之间，均获得良好的线性。

Analyse and compare what adopt a variety of pair of methods, the Michael addition reaction of ester of acerbity second of second of hydroxyl of protection of benzyl of the response of close nucleus addition that uses second nitrile and ester of formic acid second certainly, chloridize, cyanogen, reaction that take off carboxyl generates 3- benzyl oxygen radical the fifth of the ten Heavenly Stem the method of 2 nitrile, detailed discussion the action that wait and the by-product that arise possibly reach the reactant in each pace reaction, activator, dissolvent avoid a method.

通过对多种方法的分析和比较，确定采用乙腈和甲酸乙酯的亲核加成反应、氯化苄保护羟基、氰乙酸乙酯的Michael加成反应、脱羧反应生成3-苄氧基戊二腈的方法，并具体的讨论了每一步反应中反应物、催化剂、溶剂等的功能和可能产生的副产物及避免方法。

Mm, 5 μm and a UV detector. Elution was performed at a flow rate of 1 mL/min, with a gradient of methanol-acetonitrile-water starting at 80∶10∶10, increasing linearly to 86∶10∶4 in 35 min, then returning to the initial conditions in 5 min. Elution of phenacyl esters was monitored by absorbance at 254 nm. Pentadecanoic acid was used to be an internal standard.

分析所用色谱柱为ZORBAXSB C18柱，以十七酸作为内标，甲醇-乙腈-水为流动相，采用梯度洗脱(梯度洗脱程序为甲醇-乙腈-水由80∶10∶10在35 min内线性变化到86∶10∶4，然后在5 min内恢复到起始比例，流动相流速为1 mL/min)，通过测定苯乙酰甲酯在254 nm处的吸光度值来测定脂肪酸含量。

Methods: The sample that pass through handled to be abstracted twice by acetonitrile, evaporate the organic phase to dryness following defecated through the Na2SO4, cleaned-up by norm alhexalle, then analysed by HPLC (C18 column) with a gradient system of methanol-water as a mobile phase.

经处理过的样品用乙腈提取两次，将乙腈过无水硫酸钠层后挥千乙腈，正己烷洗涤净化，经过净化后进行高效液相色谱仪测定（C18柱），本方法以甲醇、水为流动相梯度洗脱，柱温35℃，在波长275 nm处测定。

For Method Ⅰ, the residues were extracted from homogenized tissue with acetone-ethylacetate-n-hexane (1∶1∶1, v/v/v), and then were redissolved in acetonitrile; for Method Ⅱ, the residues were extracted from homogenized tissue with acetonitrile-water under ultrasonication, and then were separated by liquid-liquid partition.

在样品前处理方法Ⅰ中，样品经丙酮-乙酸乙酯-正己烷(体积比为1∶1∶1)混合溶剂提取，乙腈转溶；在样品前处理方法Ⅱ中，样品用乙腈-水溶液均质，超声波辅助提取，液-液分配。

The sample was redissolved in the acetonitrilved in the acetonitrile-water (3:2, v/v), then analyzed using LC-MS/MS in multiple reaction monitoring mode via positive electrospray ionization with an Agilent ZORBAX SB-C18 column as the analytical column.

样品用1%醋酸乙腈溶液萃取，经Waters Sep-Pak Vac固相萃取柱净化，乙腈－甲苯（体积比为3：1）洗脱，旋转蒸发浓缩，用乙腈－水（体积比为3：2）溶解，以Agilent ZORBAX SB-C18色谱柱分离，以电喷雾电离串联质谱在正离子多反应监测模式下进行测定。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。