P＆T／GC／MS／SIS法在加氯消毒饮用水中痕量挥发性氯代烃测定中的应用

以吹扫捕集-气相色谱-质谱联用选择离子存储法(P&T/GC/MS/SIS)测定自来水中微量挥发性氯代烃,确定了最佳定性定量操作条件,同时探讨了改变原水中加氯量对三氯甲烷形成量的影响。当进样量为5.00mL时,四种氯代烃的线性范围为0～50ug/L,相关系数达0.9991以上;相对标准偏差RSD<9.8%;相对误差<7.6%,样品加标回收率为88%～128%,检测限在0.0006～0.26μg.L-1。方法操作方便,结果令人满意。     

Analysis of saturated free fatty acids from pollen by HPLC with fluorescence detection

A sensitive method for the determination of free fatty acids using 2‐(2‐(anthracen‐10‐yl)‐1H‐naphtho[2,3‐d]imidazol‐1‐yl) ethyl‐p‐toluenesulfonate (ANITS) as tagging reagent with fluorescence detection has been developed. ANITS could easily and quickly label fatty acids in the presence of the K₂CO₃ catalyst at 90 °C for 40 min in N,N‐dimethylformamide solvent. From the extracts of rape bee pollen samples, 20 free fatty acids were sensitively determined. Fatty acid derivatives were separated on a reversed‐phase Eclipse XDB‐C₈ column by HPLC in conjunction with gradient elution. The corresponding derivatives were identified by post‐column APCI/MS in positive‐ion detection mode. ANITS‐fatty acid derivatives gave an intense molecular ion peak at m/z [M+H]⁺; with MS/MS analysis, the collision‐induced dissociation spectra of m/z [M+H]⁺ produced the specific fragment ions at m/z [M–345]⁺ and m/z 345.0 (here, m/z 345 is the core structural moiety of the ANITS molecule). The fluorescence excitation and emission wavelengths of the derivatives were λ_ex = 250 nm and λ_em = 512 nm, respectively. Linear correlation coefficients for all fatty acid derivatives are >0.9999. Detection limits, at a signal‐to‐noise ratio of 3 : 1, are 24.76–98.79 fmol for the labeled fatty acids.     

高效液相色谱法测定稻·恶乳油中稻瘟净和恶霉灵的含量

本文采用高效液相色谱法 ,对稻瘟净和恶霉灵的复配制剂进行分析 ,色谱柱 2 5 0mm× 4 6mm不锈钢柱 ,内装BDSC18填充物 ,检测波长 2 2 0nm ,流动相 :乙腈 +水 =6 0 +4 0 (v/v) ;回收率 :稻瘟净 99 5 %～ 10 0 5 % ,恶霉灵 99 3%～ 10 0 6 % ,变异系数分别为 :0 41%和 0 6 9% ,为稻 恶乳油产品的质量控制建立了准确、快速的分析方法     

有机硅乳液中挥发性物质的测定

根据固相微萃取原理,对萃取条件进行了优化。优化后的HS-SPME-GC-MS(顶空固相微萃取/气相/质谱)实验条件为:采用85μm PAA纤维萃取头,萃取时间30min,萃取温度室温,解吸时间5min。在此条件下对3种有机硅乳液进行分析,通过计算机数据系统(质谱数据库NIST和Willy)检索及人工谱图解析,鉴定了非硅油挥发性成分。该方法的相对标准偏差为0·57%~2·59%。     

Development of high-performance liquid chromatography criteria for determination of grades of commercial olive oils. Part I. The normal ranges for the triacylglycerols

Criteria for authentic olive oils were developed from isocratic high-performance liquid chromatography analyses of 99 olive oils from the major Mediterranean producers in the 1983–1986 crop years. Authentic olive oils include extra virgin, virgin and pure or refined oils, but exclude all reesterified and adulterated oils. The extra virgin through pure grades will have a combined area for the LOO (C_18:2C_18:1C_18:1), LOP (C_18:2C_18:1C_16:0), OOO (C_18:1C_18:1C_18:1), POO (C_16:0C_18:1C_18:1), POP (C_16:0C_18:1C_18:1), and SOO (C_18:0C_18:1C_18:1) peaks between 82.0 and 92.6% of the total area (L, linoleic; O, oleic; P, palmitic; S, stearic). Authentic oils will have ratios of LOO/LOP and OOO/POO that coincide with a line defined by OOO/POO=0.7844(LOO/LOP)+0.0968; correlation coefficient is 0.885. Authentic oils will not have a trilinolein (LLL) peak over 0.5% in area. Neither triolein (OOO) nor any other single peak suffices to characterize an olive oil sample as one of the authentic grades.     

高效液相色谱法在农药残留分析中的应用

介绍了高效液相色谱法在农药残留分析中的应用,列举了一些杀虫剂、除草剂、杀菌剂的分析方法,指出了高效液相色谱法在农药残留分析中发展方向。     

18%克·福种衣剂高效液相色谱测定

本文采用高效液相色谱法，以甲醇：水（５０：５０）作为流动相，采用ＯＤＳ－Ｃ１８色谱柱， 成功地测定了克·福种衣剂中有效成分含量。     

松节油催化热异构产物的气相色谱-质谱分析

用气相色谱-质谱联用技术(GC-MS)对Pd/C催化剂上松节油直接催化热异构的反应产物进行了分析鉴定,共分离出46个峰,鉴定出43个化合物,其中主要产物为单环单萜烯苧烯、α-焦烯、1,3,5,5-四甲基-1,3-环己二烯、无环单萜烯3,4-二甲基-2,4,6-辛三烯、2,6-二甲基-2,4,6-辛三烯、双环单萜烯莰烯、单环单萜烃对伞花烃,其相对质量分数分别为:57.87%、2.92%、1.45%、5.59%、7.15%、2.78%、3.39%。分析鉴定结果表明,松节油在Pd/C催化剂上发生开环异构生成单环单萜为主反应,并伴随深度开环异构、分子间氢转移、水合重排等副反应,倍半萜只发生极少量的异构化反应,蒎烯转化率为90.04%,蒎烯可高选择性地开环热异构制备单环单萜苧烯,苧烯选择性为73.17%。     

N-乙基-N-苄基间磺酸苯胺中异构体的分离研究

对N-乙基-N-苄基间磺酸苯胺中间位、对位及邻位异构体进行了分离研究，用苯甲醛邻磺酸与N-乙基-N-苄基闯磺酸苯胺混合物缩合，制成衍生物，再用HPLC(色谱柱：CLC-ODS，检测波长：254nm，流动相：甲醇／四丁基溴化铵=60％／40％)分离，可使异构体得到有效分离，并能判断N-乙基-N-苄基间磺酸苯胺商品中间位物主含量的高低。     

Kinetics of the enzymatic degradation of poly(vinyl acetate) in solution

The enzymatic degradability of poly(vinyl acetate) was investigated in toluene solutions at various temperatures with hog pancreas lipase. The polymer degraded by specific scission to yield oligomeric products with a molecular weight of 700. Continuous distribution kinetics were used to determine the rate coefficients. The variation of the rate coefficients with the temperature indicated an optimum at 55°C. The p‐toluene sulfonic acid catalyzed degradation of poly(vinyl acetate) was also investigated. The degradation mechanism was random chain scission, and the energy of activation for degradation was determined from the variation of the rate coefficients with the temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2579–2582, 2003