对甲基苯磺酰氯衍生化液相色谱法测定土壤中草甘膦

建立简单、灵敏的土壤中草甘膦残留量的高效液相色谱检测方法.土壤样品用0.6 mol·L-1 KOH提取,经对甲基苯磺酰氯衍生化后,注入C18柱中分离,用紫外检测器在235 nm波长检测,流动相组成为0.05 mol·L-1磷酸盐缓冲液(pH 5.5)∶甲醇=65∶35(V∶V).样品中草甘膦浓度在0.5～40 mg·L-1范围内与峰面积呈线性关系(R2=0.9998).草甘膦的最小检出量(LOD)为2×10-10 g,土壤中最低检出浓度(LOQ)为0.02 mg·kg-1,平均回收率及变异系数分别为81.3%～98.3%和0.66%～5.63%.     

HPLC法和LC-MS/MS法测定饲料中黄曲霉毒素B1含量的比较

比较了HPLC光化学衍生化法、HPLC三氟乙酸衍生化法、LC-MS/MS法对饲料中黄曲霉毒素B₁（AFB₁）的检测结果进行验证和比较,为AFB₁实验室检测工作中适宜方法的选择提供参考依据。结果表明：HPLC光化学衍生化法和HPLC三氟乙酸衍生化法均有良好的线性范围和相关系数（R≥0.999 97）,AFB₁的回收率为88.4%~104.6%,精密度均小于5%;LC-MS/MS法相关系数R≥0.999 00,AFB₁的回收率为85.3%~96.8%,精密度小于3%。提示对于饲料中AFB₁的检测,HPLC光化学衍生化法操作简单、灵敏度高、稳定性好,但检测成本较高;HPLC三氟乙酸衍生化法检测成本低,但样品基质干扰大,操作较繁琐;LC-MS/MS法定性准确,但定量准确度稍差,检验成本最高。     

柱前衍生—液质联用法快速测定葡萄中单氰胺残留

建立了丹磺酰氯(DNS)柱前衍生—超高效液相色谱—串联质谱法(UPLC-MS/MS)测定葡萄中单氰胺的方法。样品经破壁机打碎,采用丙酮超声提取,在碱性条件下下与丹磺酰氯进行衍生反应。采用电喷雾(ESI)模式电离源负离子,多反应监测(MRM)模式进行检测,外标法定量。单氰胺在0.0001~0.1 mg/kg范围内,峰面积与质量浓度之间线性关系良好,相关系数为0.991。在0.001、0.01、0.05、0.1mg/kg 4档添加水平下,葡萄中单氰胺的平均回收率为79.7%~92.9%,精密度为3.6%~7.3%,定量限为0.001mg/kg。该方法简便、快速、准确,完全满足葡萄样品中单氰胺的残留检测要求。     

柱前衍生—高效液相色谱法测定鱼粉中组胺的含量

为了建立鱼粉中组胺药物残留量测定的柱前衍生-高效液相色谱法,将样品匀浆后经高氯酸水溶液超声提取,提取液经丹酰氯衍生后,采用紫外检测器在254 nm处对组胺酮进行检测。结果表明,组胺分离效果好,检出限（LOD）为25.0 mg/kg,定量限（LOQ）为50.0μg/kg,相对标准偏差为2.11%~4.76%（n=6）,加标回收率达到79.5%~90.1%。该方法具有比较高的重现性和选择性,适用于鱼粉中组胺的残留测定。     

氨基酸分析中的柱前衍生技术

介绍了以邻苯二甲醛、氯甲酸芴甲酯、异硫氰酸苯酯、丹酰氯、二甲胺偶氮苯磺酰氯和6-氨基喹啉-N-羟基琥珀酰亚胺基氨基甲酸酯等作为衍生试剂的柱前衍生与反相高效液相色谱法相结合分析氨基酸的原理及特点。     

液相色谱法检测磺胺类药物柱后衍生反应条件优化

采用液相色谱柱后衍生法检测磺胺类药物,衍生化反应效果对检测结果有较大影响.通过正交实验,对影响衍生化反应的主要因素进行优化,得出磺胺在线柱后衍生优化条件为:流动相pH值3.0、反应温度60℃、流动相乙腈比例18％、衍生化试剂荧光胺浓度0.25mg/mL.     

衍生化-顶空固相微萃取-气相色谱法测定大鼠粪便中游离短链脂肪酸

为满足生物样品中短链脂肪酸的痕量检测需求,以氯甲酸丙酯为衍生试剂,结合顶空固相微萃取,建立了基质内衍生 顶空固相微萃取 气相色谱方法用于大鼠粪便中7种游离短链脂肪酸的测定。在最佳衍生条件（pH8、300 μL丙醇、100 μL吡啶、100 μL氯甲酸丙酯及涡旋衍生2 min）及顶空固相微萃取的条件（pH3.46、萃取温度50℃、萃取时间40 min和转速1 000 r/min）下,该方法的检出限在0.133~0.420 μmol/kg,定量限在0.444~1.400 μmol/kg,远低于其他文献中所建方法的检出限和定量限,而且线性关系好(R2>0.99),精密度和准确度高,加标回收率在65.42%~117.69%,相对标准偏差低于11.60%。该方法操作简单、快速、灵敏且廉价,完全能够满足粪便中短链脂肪酸痕量检测需求     

Quantification of long‐chain fatty acids in dissolved organic matter and soils

The objective was to develop and adapt a versatile analytical method for the quantification of solvent extractable, saturated long‐chain fatty acids in aquatic and terrestrial environments. Fulvic (FA) and humic (HA) acids, dissolved organic matter (DOM) in water, as well as organic matter in whole soils (SOM) of different horizons were investigated. The proposed methodology comprised extraction by dichloromethane/acetone and derivatization with tetramethylammonium hydroxide (TMAH) followed by gas chromatography/mass spectrometry (GC/MS) and library searches. The C_10:0 to C_34:0 methyl esters of n‐alkyl fatty acids were used as external standards for calibration. The total concentrations of C_14:0 to C_28:0 n‐alkyl fatty acids were determined in DOM obtained by reverse‐osmosis of Suwannee river water (309.3 μg g^—1), in freeze‐dried brown lake water (180.6 μg g^—1), its DOM concentrate (93.0 μg g^—1), humic acid (43.1 μg g^—1), and fulvic acid (42.5 μg g^—1). The concentrations of the methylated fatty acids (n‐C_16:0 to n‐C_28:0) were significantly (r² = 0.9999) correlated with the proportions of marker signals (% total ion intensity (TII), m/z 256 to m/z 508) in the corresponding pyrolysis‐field ionization (FI) mass spectra. The concentrations of terrestrial C_10:0 to C_34:0 n‐alkyl fatty acids from four soil samples ranged from 0.02 μg g^—1 to 11 μg g^—1. The total concentrations of the extractable fatty acids were quantified from a Podzol Bh horizon (26.2 μg g^—1), Phaeozem Ap unfertilized (48.1 μg g^—1), Phaeozem Ap fertilized (57.7 μg g^—1), and Gleysol Ap (66.7 μg g^—1). Our results demonstrate that the method is well suited to investigate the role of long‐chain fatty acids in humic fractions, whole soils and their particle‐size fractions and can be serve for the differentiation of plant growth and soil management.     

用基于邻苯二甲醛柱前衍生的高效液相色谱法测定稻米的Y-氨基丁酸含量

建立基于邻苯二甲醛（0-phthalaldehyde,OPA）柱前衍生的高效液相色谱法（highperformanceliquidchromato—graphy,HPLC）,测定了稻米中Y-氨基丁酸（Y-aminobutyricacid,GABA）的含量。结果显示：用三氯乙酸作为提取溶剂的效果最好;检测限为0．5mg／L,提取回收率为79．1％-101．5％;巨胚糙米的GABA含量显著高于常规胚糙米的,发芽后巨胚糙米的GABA积累量也高于常规胚糙米的。