乙腈

The mobile phase was 30% volume of acetonitrile, 70% volume of phosphate buffer salt(sodium hydrogen phosphate 1.12 g, sodium dihydrogen phosphate 0.18 g, add water to 1000 mL, adjusted to pH 7.6); the detection wavelength was set at 288 nm.

建立HPLC法，色谱柱：Diamonsil C18(5μm， 4.6 mm×250 mm)，流动相：乙腈－磷酸盐缓冲液（取磷酸氢二钠1.12 g，磷酸二氢钠0.18 g，加水溶解并稀释至1 000 mL，调pH值至7.6）（体积比为30：70），检测波长：288 nm。

The dyes were extracted from textiles composed of natural or chemical fibers by methanol under ultrasounication, and then eluted with gradient by acetonitrile and 5 mmol/L ammonium acetate from an RP-C18 column with two segments in effluents. The first effluents accommodated Acid Red 26, Direct Blue 6, Direct Black 38 and Direct Red 28 with negative ionization mode, while the second accommodated Basic Red 9, Basic Violet 14, Disperse Blue 1, Disperse Orange 11 and Disperse Yellow 3 with positive ionization mode. Thus the investigated compounds could be identified simultaneously with single-run analysis no matter which type of the fibre the sample was and no matter which category of the dye the analyte was.

用甲醇超声同时提取天然纤维和化学纤维上的染料，以5 mmol/L乙酸铵和乙腈为流动相在C18柱上于前段洗脱酸性红26、直接蓝6、直接黑38和直接红28（采用电喷雾质谱负离子模式检测），于后段洗脱碱性红9、碱性紫14、分散蓝1、分散橙11和分散黄3（采用电喷雾质谱正离子模式检测），实现了对不同种类纤维织品中分属4类性质不同染料的一次提取和一次分析检测。

The conditions was as follows: Maxima 820 workstation,Hypersil column ODSC_(18)(4.6mm×200mm 5μm),UV detective wavelength 247nm,Flow rate 1.0ml/min,sensitivity 0.01 AUFS Mobile phase is composed of acetonitrile,H_2O,methanol(45:55:1).By which the inerference of impurity may be avoided and there is a good linear relationship between concentration and peak area.

本文建立了体内外氟比洛芬样品的HPLC测定方法：色谱柱：4.6mm×200mm Hypersil ODSC_(18)(4.6mm×200mm 5μm，)紫外检测波长247nm；流动相为乙腈：水：甲醇=45：55：1，流速：1.0ml/min；柱温：室温；灵敏度：0.01AUFS，进样量：20μL，该法可将氟比洛芬与杂质分离，浓度与峰面积之间呈良好的线性关系，满足分析要求。

Study on HPLC method for analyzing of trace pigments in ready-to-drink tea was conducted by using different eluants with acetonitrile as mobile phase.

以含乙腈的流动相作为洗脱剂，对茶饮料中微量色素物质的HPLC分析方法进行了研究。

Analysis was carried out on a Hypersil ODS2 column(4.6 mm×250 mm,5 μm) with acetonitrile-0.1% glacial acetic acid as the mobile phase,and eluates were detected by an evaporative light scattering detector.

采用Elite Hypersil ODS2(4.6 mm×250 mm，5μm)色谱柱，乙腈-0.1%冰醋酸水溶液为流动相梯度洗脱，流速1mL.min-1，以蒸发光散射检测器检测，记录70 min色谱图。

The lung tissues were extracted with acetonitrile and 0.1M potassium dihydrogen phosphate buffers. The extracts purified by C18 solid-phase extraction cartridges. The eluates were determined by HPLC at 288nm. Limits of detection were 0.025 ug/mL for tilmicosin in plasma and 0.025ug/g for tilmicosin in lung, respectively.

采用C18 SPE柱分离和提纯血浆中的替米考星，用乙腈和0.1M磷酸二氢钾缓冲液提取肺脏中的替米考星，用C18 SPE柱净化，均采用反相高效液相色谱测定替米考星，检测波长288nm。

Methods The amino acids in the injections were pretreated with 6-aminoquinolyl-N-hydroxysuccinimdyl separately and their derivatives were analyzed on Waters 2695 HPLC using AccQ-Tag column. Gradient eluents consisted of sodium acetate solution (pH 4.95), acetonitrile and water. The Detection wavelength was 248 nm and column temperature 37℃.

采用AccQ-Tag法，以6-氨基喹啉－N-羟基琥珀酰亚胺基甲酸酯为衍生试剂，与复方氨基酸注射液(18AA-V)中17种氨基酸柱前衍生，用Waters 2695 HPLC仪器，AccQ-Tag柱，以醋酸钠(pH 4.95)缓冲液为流动相A，乙腈为流动相B，水为流动相C进行梯度洗脱，检测波长为248 nm，柱温为37℃，进样量为5μL。

The mobile phase was a mixture of 20 mmol\L methylsulfonic acid and 20% acetonitrile\water at the ratio of 87∶13.

流动相为20mmol\L甲基磺酸-20%乙腈水混合溶液(体积比为87∶13)，流速为1.0mL\min

The water based food simulants,including deionized water,3％ acetate acid solution and 10 ethanol solution,were directly sampled into HPLC,while the refined olive oil needs to be successively extracted by hexane and methanol/acetonitrile mixture (volume ratio=1∶1) prior to sampling.

水基食品模拟物（去离子水、3%乙酸溶液、10%乙醇溶液）中的目标分析物可直接进样，精制橄榄油中的目标分析物依次通过正己烷和甲醇乙腈混合液（体积比1∶1）萃取后进样。

Sample matrix are discharged by the pre-column. The mobile phases applied consisted of 0.1% HOAc (pH3.0) acetonitrile-water on extraction column with UV detection at 225nm. Then, coupled-column liquid chromatographic methods for the direct analysis of atrazine and simazine in urine was established. As a result, the system showed good chromatographic property in the on-line analysis of atrazine and simazine in urine.

使用该系统对尿中的莠去净和西玛津残留进行了分离分析，以含有0.1%乙酸的酸性水缓冲液对加标尿液中莠去净类化合物保留在预柱上，干扰分析的大分子被排阻而无保留通过，其它干扰分子保留小而通过，再切换六通阀，以乙腈和0.1%乙酸水溶液进行梯度洗脱，进而在下一级ODS分析柱上进行分离（紫外检测225nm），两种除草剂的分离分析取得了良好的定性定量结果

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。