气相色谱法测定阔草清在土壤中的残留量

研究了气相色谱法测定土壤中阔草清的残留量，阔草清用丙酮：０．１Ｎ盐酸＝９：１提取。阔草清的ｐＫａ为４．６，可以利用它在不同ｐＨ溶液中量不同状态进行纯化，由于阔草清的低挥发性和热不稳定性，所以在进行气相色谱分析前，先进行甲基化，形成Ｎ－甲基阔草衍生物，再于气相色谱仪上测定，本实验采用添加法测定回收率，添加水平为００．０μｇ／ｋｇ，平均回收率为９０．５％～９６．７％，最小检出限为２．５μｇ／ｋｇ。本文     

免疫亲和柱法测定小麦中黄曲霉毒素

本文研究了用正相高效液相色谱仪附荧光检测器测定小麦中黄曲霉毒素B1、B2、C1、C2。黄曲霉毒素用甲醇－水（70＋30）提取，提取液经免疫亲和柱富集、净化，于液相色谱仪上测定。本实验采用添加法测定回收率，添加水平为0.11-3.9μg/kg时，其平均回收率为87.9%-102.5%。本方法的最低检测限为0.1μg/kg。     

DDTC-MIBK萃取火焰原子吸收法测定铜

研究二乙基二硫代氨基甲酸钠－甲基异丁基甲酮（DDTC－MIBK）体系萃取溶液中铜（Ⅱ），火焰原子吸收测定微量铜的方法，测定的灵敏度为0．028μg/ml/1％吸收，检出限为0．020μg/ml，线性范围为0－5．0μg/ml。标准铜加入样品后的回收率为98．2％－105％，相对标准偏差3．07－5．56％，成功地测定了新鲜水果及桔子，黄桃等罐头食品中的微量铜。     

凝胶渗透色谱－液相色谱－串联质谱法测定水产品中性激素

建立水产品中性激素的凝胶渗透色谱净化－超高效液相色谱－串联质谱分析方法。采用乙酸乙酯提取样品,经GPC净化后, LC－MS／MS测定,外标法定量。流动相为乙腈和0．1％甲酸水溶液,梯度洗脱,电喷雾正离子多反应模式监测。3种性激素在0．5～20．0μg／L线性范围内,相关系数大于0．998,定量限为0．3μg／kg,回收率为88．6％～96．4％,相对标准偏差为1．84％～6．24％。本方法灵敏度高、重现性好,适用于水产品中性激素的测定。     

超高效液相色谱法代替气相色谱法测定氟乐灵含量

建立了一种超高效液相色谱法测定氟乐灵含量的方法。样品用甲醇定容,以C18为固定相,甲醇＋水为流动相,TUV检测器检测,以保留时间定性,以峰面积定量。结果表明：在0．05～51μg／mL范围内浓度与峰面积线性关系良好,相关系数r=0．99997;在0．01～0．5mg／kg添加浓度范围内,方法平均回收率为65．8-90．6％,相对标准偏差为2．7-7．9％,检出限为0．01g／kg,定量限为0．025g／kg。方法灵敏度高、稳定性好,适用于氟乐灵含量的测定。     

加速溶剂萃取－超高效液相色谱法测定沉积物中硝基呋喃

建立了加速溶剂萃取－超高效液相色谱测定沉积物中硝基呋喃类药物（呋喃唑酮、呋喃它酮、呋喃西林、呋喃妥因）的分析方法。样品经乙腈萃取后,超高效液相色谱分离,流动相为乙腈和0．1％甲酸的2 mmol／L乙酸铵溶液。在优化条件下,4种硝基呋喃类药物在5～200μg／L浓度范围内线性关系良好,相关系数R2＞0．998,方法检出限均为5．0μg／kg。在10～50μg／L添加水平之间的回收率为85．1％～93．6％,相对标准偏差为1．93％～5．04％。该方法灵敏、准确、高效、分析速度快,适用于沉积物中4种硝基呋喃类药物的测定。     

环境中异丙草胺农药残留分析方法

建立了新型除草剂异丙草胺在环境水及土壤中的残留分析方法。水样用二氯甲烷提取后即可进样测定;土样用石油醚：丙酮=1：1(v／v)的混合液提取,石油醚液液分配,氟罗里硅土层析柱净化,然后GC-ECD行检测。水及土壤中异丙草胺残留方法的最小检测浓度分别为0．2μg／L和1．8μg／kg,回收率在85.7％～102.6％之间,变异系数为1．3％～6．6％。     

食用植物油中溶剂残留量的顶空气相色谱标准加入法测定研究

对食用植物油中的溶剂残留测定方法进行了改进。用样品作基体配制标准溶液,采用顶空进样气相色谱测定,标准加入法定量。方法线性范围在ofμg／g-200μg/g,检测低限1．0μg/g,在1-μg／g-200μg／g浓度范围内,标准添加回收率为87．8％-107．4％．相对标准偏差6．06％-11．8％。本方法采用标准加入法进行定量,样品和标准的基体一致,避免了基体的影响,该法简便、快速,适合食用植物油中的溶剂残留的分析。     

气相色谱-质谱法测定牙膏中的二甘醇

利用毛细管柱气相色谱-质谱（GC—MS）测定牙膏中二甘醇的量,检出限为5mg／kg,二甘醇的线性范围为5μg／mL－500μg／mL,回收率为95．2％～102．2％,相对标准偏差（RSD）为1．19％～1．54％。     

高效液相色谱法测定5—氯—2—氨基三氟甲苯

本文报道了有机中间体5－氯－2－氨基三氟甲苯的高效液相色谱分析方法。本方法采用Lichrosobr SI60色谱柱，以正己烷／甲醇（98／2）为流动相，检测波长为254nm。线性范围20μg/ml-100μg/ml（r=0.99982),回收率为98．89％－100．1％（n=3),标准偏差小于0．2％。     

气相色谱法测定大豆中克百威及其代谢物的残留量

建立用气相色谱法测定克百威及其代谢物3-羟基克百威在大豆、大豆植株和土壤中残留分析方法。当添加质量分数为0.05～0.2mg/kg时,克百威在大豆、大豆植株和土壤中回收率分别为87.2%～84.8%、87.7%～85.9%、88.6%～87.1%,变异系数在3.6%～5.0%之间;3-羟基克百威在大豆、大豆植株中回收率分别为87.6%～85.2%、89.3%～87.7%,变异系数在1.5%～5.0%之间。     

化妆品中防腐剂7-乙基二环噁唑啉的气相色谱/质谱检测方法的研究

建立了化妆品中防腐剂7-乙基二环噁唑啉的气相色谱/质谱检测方法。采用Agilent DB-5MS石英弹性毛细管色谱柱,进样口温度250℃,柱温40℃,以15℃/min升至130℃,载气He,EI离子源,选择m/z55、83、113、143分别作为定量离子峰,并根据这4个抽出离子的峰面积比进行确证。结果表明,在此条件下7-乙基二环噁唑啉在0.1～10g/mL范围内的线性关系良好,检出限为1.75μg/kg,不同种类化妆品中7-乙基二环噁唑啉的加标回收率在72.1%～113.0%范围内,相对标准偏差（RSD）为1.92%～8.53%。此方法操作简便,分离速度快,检出限低,适用于对化妆品中防腐剂7-乙基二环噁唑啉的检测。     

Occurrence of Conjugated Linolenic Acids in Purified Soybean Oil

A high-performance liquid chromatographic (HPLC) method is described for the determination of conjugated linoleic acids (CLA) and conjugated linolenic acids (CLN). Methyl esters prepared from purified lipid fractions of soybean oil were analyzed using an HPLC system equipped with photodiode-array detector to detect peaks having maximum absorption around 233 and 275 nm. These peaks were concentrated by AgNO₃-silicic acid column chromatography and reversed-phase HPLC. The structural analysis, of dimethyloxazoline (DMOX) derivatized methyl esters, using gas chromatography–mass spectrometry (GC–MS) showed the occurrence of 9,11- and 10,12-CLA and 8,10,13-, 8,10,12-, and 9,11,13-CLN. The comparison of these conjugated fatty acids with authentic isomers by HPLC revealed the presence of isomeric mixtures of CLA [cis (c),trans(t) or t,c and t,t] and CLN (c,t,t or t,t,c and t,t,t). Traces of 9,11- and 10,12-CLA (c,t or t,c) were found in crude oil. CLN isomers (8,10,12-18:3 and 9,11,13-18:3) were found to be forming during the bleaching phase of soybean oil processing. 8,10,13-CLN and 9,11- and 10,12-CLA (t,t) were only found in soybean oil after the deodorization step. CLN contents in commercial soybean oil varied from 387 to 1,316 mg/kg oil. A decreased level of bleaching earth and temperature resulted in a reduced CLN content. It is possible that CLN would be derived from the linoleate hydroperoxides formed during the processing and storage of soybean oil.     

A simple capillary column GC method for analysis of palm oil-based polyol esters

A reliable, simultaneous analysis of palm oil polyol esters using capillary column GC is described. The polyol esters were esterified from palm oil methyl esters (POME) and palm kernel oil methyl esters (PKOME) with trimethylolpropane [2-ethyl-2-(hydroxymethyl)-1,3-propanediol; TMP] to produce the biodegradable base oil for lubricant production. Analysis was performed using a high-temperature capillary column, SGE HT5 operated at a temperature gradient of 6°C/min starting from 80 to 340°C. Before injection, the sample was derivatized with N,O-bis (trimethylsilyl)trifluoroacetamide in ethyl acetate at 40°C for at least 10 min. This procedure provides a complete separation of reaction products: TMP, methyl esters, monoesters (ME), diesters (DE), and triesters (TE). As expected, the ME from palm kernel oil was resolved into five major peaks, DE into seven peaks, and TE into 10 peaks. Since no standard was available for this sample, the identities of the peaks were established by a secondary standard that was derived from pure methyl esters. This GC method has made possible the simultaneous determination of reaction product compositions in order to assess the extent of reaction.     

GPC-GC-MS法测定大豆中的敌敌畏

基于凝胶渗透色谱技术(GPC)的去油酯效果,建立了气相色谱(GC)-质谱(MS)选择离子法测定大豆中的敌敌畏残留量的检测方法。样品经凝胶渗透色谱净化后,经过自动快速浓缩后直接用GC-MS进行检测并确证,最后用外标法进行定量。方法检出限为0.002 mg/kg,加标水平为0.05 mg/kg时,样品平均回收率为89%,相对标准偏差为3.1%。该方法操作简单,净化效果好,具有良好的回收率、精密度,而且检出限低,适合于日常大豆中敌敌畏残留量的检测。     

叶面喷施有机硒对大豆不同器官吸收Cd、Pb的影响

通过对大豆进行叶面喷施硒蛋氨酸的盆栽试验,发现能明显提高大豆籽粒硒水平,籽粒富集Se的能力约是对照的6倍,不同器官富集Se的规律为:叶粒茎壳,而其产量没有发生明显变化。大豆叶片吸收Cd,Pb的能力最强,其中叶片Cd含量为0.30~0.90 mg/kg,Pb含量为1.0~1.9 mg/kg,叶片Pb含量是籽粒的42~98倍。大豆植株里的Se对籽粒、壳、叶、茎等各器官吸收Cd、Pb均表现出拮抗作用,对Cd的拮抗作用较强,对Pb的拮抗作用较弱。     

奶粉中苯酚类污染物残留量检测方法研究

建立气相色谱法检测奶粉中苯酚类污染物残留的分析方法,样品经过酸性水溶液提取,采用正己烷萃取,碳酸钾溶液反萃取,乙酸酐衍生,GC-ECD法同时检测,外标法定量,阳性样品采用GC/MS确证,方法回收率为75.8%~93.5%,RSD为2.61%~4.88%,方法检测限为:0.8~.3.0μg/kg。     

气相色谱-质谱法测定纺织品中的二辛基锡

构建了气相色谱-质谱(GC-MS)测定纺织品中二辛基锡的方法。应用液液萃取法提取纺织品中的二辛基锡,通过四乙基硼化钠衍生后,使用用GC-MS总离子流图和选择离子进行定性检测,使用选择离子的质谱峰进行定量测定。该方法样品前处理简单,使用外标标准曲线法对二辛基锡检测,在0.3～2.0μg/mL范围内呈良好的线性关系,加标回收率在93.1%～102.4%之间,可应用于纺织品中有机锡的检测。     

Male-Produced Sex Pheromone of the Stink Bug Edessa meditabunda

Edessa meditabunda is a secondary pest within the piercing-sucking stink bug complex that attacks soybean crops in Brazil. The behavioral responses of males and females to aeration extracts from conspecifics suggested the presence of a male-produced sex pheromone. Gas chromatographic (GC) analysis of male and female aeration extracts revealed the presence of two male-specific compounds in a ratio of 92:8. Gas chromatographic -electroantennographic detection (GC-EAD) assays indicated that the major component is bioactive for females, supporting the behavioral data. Analysis of the mass and infrared spectra of the male-specific compounds suggested that they were both methyl-branched long-chain methyl esters. On the basis of the mass spectra of the respective hydrocarbons obtained by micro derivatizations, the structures of these methyl esters were proposed to be methyl 4,8,12-trimethylpentadecanoate (major) and methyl 4,8,12-trimethyltetradecanoate (minor). An 11 step synthetic route that was based on a sequence of Grignard reactions, starting from cyclopropyl methyl ketone, was developed to obtain synthetic standards with a 7.9 % overall yield for the major compound and a 9.9 % yield for the minor. The synthetic standards co-eluted with the natural pheromones on three different GC stationary phases. Y-tube olfactometer assays showed that the synthetic standards, including the major compound alone and a mixture of the major and minor compounds in the proportion found in natural extracts, were strongly attractive to females.     

α-三联噻吩的β-环糊精包结物荧光检测

α-三联噻吩是广泛存在于菊科植物中的一种光活化物质，但含量较低，一般很难检测。本试验报道了一种利用荧光分光光度法分析痕量α-三联噻吩的方法。结果显示：在激发波、发射波狭缝宽度均为5．0nm，激发波长为352nm，发射波长428nm时，经肛环糊精包结后的α-三联噻吩荧光强度比同浓度未包结的α-三联噻吩荧光强度显著增强，在浓度为0．02～0．10μg／g的范围内呈良好的线性关系(R值为0．9998)。