分散固相萃取-气相色谱串联质谱法快速测定血清中6种新型溴系阻燃剂

建立了分散固相萃取-气相色谱串联质谱法快速提取、净化并测定血清中6种新型溴系阻燃剂的分析方法。血清样以正己烷/丙酮混合液提取,Na Cl和无水Mg SO4盐析后,提取液经含有C18和无水Mg SO4的离心管分散净化,采用GC-EI-MS/MS在多反应监测模式下测定五溴甲苯、五溴乙苯、六溴苯、2,3-二溴丙基-2,4,6-三溴苯基醚和1,2-双(2,4,6-三溴苯氧基)乙烷,采用GC-NCI-MS在选择离子监测模式下测定十溴二苯乙烷,同位素内标法定量。除十溴二苯乙烷外其余阻燃剂在1~100μg/L范围内线性关系良好,相关系数均大于0.999。在0.02,0.2和2μg/L三个浓度添加水平下平均回收率范围为89.4%~136.6%,相对标准偏差(RSD)小于18%。除十溴二苯乙烷检出限为350 ng/L外,其余待测物检出限在4.2~32 ng/L。方法适合血清中多种新型溴系阻燃剂的同时前处理与测定。     

同位素稀释-超高效液相色谱-串联质谱法测定纺织品中的六溴环十二烷

建立了同时测定纺织品中α-,β-,γ-六溴环十二烷的同位素稀释-超高效液相色谱-串联质谱分析方法.不同类型的纺织品样品采用加速溶剂萃取法,以正己烷-丙酮(体积比1∶1)混合液为萃取溶剂,在10.3 MPa和80℃下,静态循环萃取3次,每次5 min,萃取液经ENVI-CarbⅡ/PSA固相萃取柱净化,收集二氯甲烷-正己烷(体积比2∶3)洗脱液,采用Waters ACQUITY UPLC BEHPhenyl色谱柱(50 mm×2.1 mm,1.7μm),以甲醇-水为流动相梯度洗脱分离后进行UPLC/MS/MS多反应监测模式下的定性及定量分析.结果表明,α-,β-,γ-六溴环十二烷测定方法的定量限为0.5μg/kg,在0.5~10μg/kg浓度范围内,低、中及高3个添加水平的平均回收率为84.2%~93.7%,日内精密度均小于10%,日间精密度均小于12%.本方法准确快速,且灵敏度高,可用于纺织品的实际检验.     

超高效液相色谱-串联四极杆质谱法测定水产品中氯霉素残留量

建立超高效液相色谱-串联四极杆质谱法测定水产品中氯霉素残留量的方法。样品均质后经乙酸乙酯提取,正己烷脱脂(或用固相萃取柱净化),超高效液相色谱分离,串联四级杆质谱检测,同位素内标法定量。方法在0.05～1.0μg/kg的添加范围内的平均回收率为84.9%～103.3%,相对标准偏差为3.2%～5.2%,定量检测限为0.02μg/kg。方法适用于各种水产品基质的氯霉素残留检测。     

气相色谱-质谱法测定叶酸片中三氯丙酮的残留量

建立了气相色谱-质谱联用方法测定叶酸片中三氯丙酮溶剂的残留量。叶酸片研磨过筛后采用N,N二甲基甲酰胺溶剂超声提取,Rtx-w ax毛细管色谱柱分离。通过气相色谱-质谱全扫描总离子图定性,单离子监测模式定量检测叶酸片中三氯丙酮的残留量。在0.5～15.0μg/mL质量浓度范围内,三氯丙酮的浓度和色谱峰面积线性拟合关系良好(r=0.9998),方法检出限为0.15μg/mL,相对标准偏差2.0%,加标回收率为93.0%～105.3%。建立的方法,能有效消除复杂基质带来的干扰,适用于叶酸片中三氯丙酮残留量的检测。     

GC-MS测定水产品中氯霉素的残留量

报道了利用气相色谱-质谱联用技术分析水产品中氯霉素的残留量。试样中的氯霉素用乙酸乙酯提取,经正己烷去脂,及硅烷化试剂衍生后,用配有负化学电离源的气-质联用仪测定,选择离子的质量数为466、468、470、376。衍生物的峰面积与样品质量浓度在0.5~250μg/L范围内呈良好的线性,相关系数为0.9996。当添加水平为0.5~10.0μg/kg时,回收率为74.8%~84.8%,相对标准偏差为4.90%~8.99%。     

HPLC-MS/MS同时测定水产品中喹烯酮、喹乙醇和5种大环内酯类抗生素残留

建立了水产品中喹烯酮、喹乙醇和5种大环内酯类抗生素同时测定的高效液相色谱串联质谱法。向样品中加入无水硫酸钠,以乙酸乙酯-乙腈的混合溶液为提取剂,用正己烷净化。以乙腈-10 mmol/L甲酸铵溶液为流动相,流速为0.3 mL/min,以Hypersil GOLD为色谱分离柱,用配有电喷雾离子源的三重四极杆质谱进行定性定量分析。在1～1000 ng/mL范围内,7种药物呈良好线性关系。在鲫鱼、南美白对虾和甲鱼空白肌肉中添加水平为2～10μg/kg时,该方法的回收率为67.52%～108.89%,相对标准偏差为4.2%～14%,方法检测限为1μg/kg,定量限为2μg/kg。方法适用于同时测定水产品中喹烯酮、喹乙醇和5种大环内酯类药物的残留量。     

浓缩苹果汁中多种拟除虫菊酯类农药残留量的气相色谱-质谱测定方法

采用固相萃取技术,以丙酮和正己烷提取,C18小柱净化,用GC MS可同时测定浓缩苹果汁中4种拟除虫菊酯类农药的残留量。方法的回收率在96.5%～111.9%之间,相对标准偏差为1.7%～6.9%,最低检测浓度在0.02～0.10μg kg之间。     

气相色谱法同时测定山药和葛根中27种有机氯及拟除虫菊酯农药残留量

建立了山药和葛根中20种有机氯和7种拟除虫菊酯农药残留的提取、净化及其残留量测定的方法。样品采用丙酮-正己烷(4:3,V/V)提取,经凝胶渗透色谱净化后,采用气相色谱-电子捕获检测器检测。结果表明山药和葛根样品基质4水平添加条件下,27种农药的回收率(n=7)为80.1%～103.7%,相对标准偏差为1.9%～11%,最低检测限为0.09～1.82μg/kg,符合农药多残留检测要求。方法可用于山药和葛根中多种有机氯及拟除虫菊酯农药残留量的检测。     

植物性食品中锐劲特残留量的检测方法研究

研究了测定植物性食品中锐劲特残留的气相色谱方法。试样经丙酮提取,正己烷反萃取,中性氧化铝加少量活性炭柱进行净化,以GC/ECD方式测定,外标法定量。实验表明:试样中添加0.005~0.25 mg.kg-1水平的锐劲特,标准添加回收率为84%~110%,方法检出限为5μg.kg-1。同一样品中6次测定锐劲特残留量的相对标准偏差小于5%。     

加速溶剂萃取-气相色谱法测定土壤中的联苯菊酯

建立了加速溶剂萃取-色谱法测定土壤中的联苯菊酯残留量的方法.土壤样品与无水硫酸钠以1∶2(质量比)混合后,再加适量中性氧化铝,用丙酮-石油醚(体积比为1∶1)在加速溶剂萃取仪上以10.3 MPa、80℃提取5 min,Florisil小柱净化,然后采用ECD气相色谱测定,在0.56、1.12 μg/kg两个添加水平下,联苯菊酯的加标回收率为72.7%～87.2%,检出限为0.1 μg/kg.测定结果的相对标准偏差为9.3%(n=8).该法能有效地消除复杂基质带来的干扰,可以作为日常样品中联苯菊酯残留量的检测和确证方法.     

A new process for preparation of soybean protein concentrate with hexane-aqueous ethanol mixed solvents

A new process for the preparation of soybean protein concentrate (SPC) by directly extracting full-fat soy flour with a mixture of hexane and aqueous ethanol was established. Compared with conventional methods, it has some advantages, such as saving energy and reducing protein denaturation caused by heat action during solvent recovery, because this process saves one step of solvent recovery. The effects of aqueous ethanol concentration and the mixure ratio (hexane to ethanol) on the degree of protein denaturation and product quality were investigated, on the basis of which the orthogonal tests were performed. The optimum technical parameters were obtained by analyzing the results of the orthogonal tests with statistical methods. We found that SPC can be obtained by extracting full-fat soy flour under the following conditions: mixture ratio hexane: 90% ethanol, 9:1, v/v; extraction temperature, 45 degrees C; ratio of solid to solvents, (1:2 w/v); and 5 repeated extractions (15 min each time). The results of quality analysis showed that solubility of the product was improved significantly [nitrogen solubility index (NSI) 46.6%] compared with that for ethanol washing of protein concentrate (NSI 8.7%).     

Ion pair assisted micro matrix solid phase dispersion extraction of alkaloids from medical plant

A novel micro matrix solid phase dispersion method was successfully used for the extraction of quaternary alkaloids in Phellodendri chinensis cortex. The elution of target compounds was accomplished with sodium hexanesulfonate as the eluent solvent. A neutral ion pair was formed between ion-pairing reagent and positively charged alkaloids in this process, which was beneficial for selectively extraction of polar alkaloids. Several parameters were optimized and the optimal conditions were listed as follows: silica gel as the sorbent, silica to sample mass ratio of 1:1, the grinding time of 1 min. The exhaustive elution of targets was achieved by 200 µL methanol/water (9:1) containing 150 mM sodium hexane sulfonate at pH 4.5. The method validation covered linearity, recovery, precision of intraday and interday, limits of detection, limits of quantitation, and repeatability. This established method was rapid, simple, environmentally friendly, and highly sensitive.     

在中性条件下用亚氯酸钠和双氧水氧化芳香醛

本文优化了中性环境中亚氯酸钠和双氧水氧化醛的反应条件,采用正交实验设计法考察了溶剂、亚氯酸钠和双氧水的用量以及反应温度对醛氧化产率的影响,确定最佳工艺条件为以乙醇作溶剂,亚氯酸钠、双氧水、醛的摩尔比为1.1: 2: 1。在优化的反应条件下对醛进行底物扩展验证其适应性,并通过放大实验说明其工业生产适用性,本方法具有产率高、后处理简单、副产物绿色无污染的优点。     

Miscibility of sodium dodecyl sulfate and sodium decyl sulfate in the adsorbed film and micelle

The interfacial tension of the aqueous solution of sodium dodecyl sulfate (SDS) and sodium decyl sulfate (SDeS) mixture against hexane was measured as a function of the total molality and composition of the surfactant mixture at 298.15 K under atmospheric pressure. The compositions of adsorbed film and micelle were evaluated numerically by applying the thermodynamic relations to the experimental results. These results were shown in the form of the phase diagrams of adsorption and micelle formation and compared with those of the aqueous solution of sodium perfluorooctanoate (SPFO) and SDeS mixture. It was found that the diagrams of SDS and SDeS system have swollen cigar shapes and are quite different from those of SPFO and SDeS system which show non-ideal mixing both in the adsorbed film and micelle. This finding was attributed to the fact that the interaction between fluorocarbon and hydrocarbon chains is weaker than that between hydrocarbon chains.     

正交实验法在小麦粉中甲醛振荡提取条件的应用研究

小麦粉中甲醛的提取问题是一个比较复杂的多因素问题。采用正交实验法,选用L9(34)正交实验表,在提取试剂、提取温度、提取时间等多个因素和水平中优选小麦粉中甲醛振荡提取的最佳条件。实验中甲醛提取量采用Nash试剂柱前衍生高效液相色谱法测定。结果表明,提取温度是小麦粉中甲醛提取的最主要因素,最佳的提取条件为提取温度30℃、提取液为硫酸钠、提取时间为40min。     

阴离子表面活性剂聚二硫二丙烷磺酸钠的合成

利用硫化钠与硫磺反应制备二硫化钠,然后将二硫化钠与1,3-丙磺酸内酯反应,合成了一种可作为电镀添加剂的阴离子表面活性剂——聚二硫二丙烷磺酸钠(SPS)。采用核磁共振氢谱对合成产物进行结构表征,确认了产物结构及产率。通过正交试验研究了产物产率与反应物配比、反应温度、溶剂加入量等因素之间的关系,找出了最优合成条件:第一步合成二硫化钠的反应中,硫化钠/硫磺物质的量比为1∶1.3,温度55℃,加水量18 mL;第二步合成SPS的反应中,1,3-丙磺酸内酯/硫化钠物质的量比为1.7∶1,温度40℃,溶剂量75 mL,产物的最高产率可达到95.8%。     

水质COD测定方法的改进研究

国标GB 11914–1989测定水质COD的方法存在分析时间长、工作量大、能耗高,毒性大,且易造成二次污染的缺点,因此在国家标准的基础上对各实验条件进行优化改进。针对国标方法中的溶液酸体系、回流时间、催化剂、氧化剂4个因素,设计了三因素三水平和一因素两水平的混合正交实验方案来研究改进COD的测定方法。结果表明,当氧化剂为重铬酸钾,回流时间为40 min,硫酸与磷酸的体积比为3∶1,催化剂为硫酸银–硫酸铜(质量比为1∶1)时即为测定水质COD的最优条件。改进后的方法对水样COD测定结果的相对标准偏差为1.79%(n=5),对COD标准物质测定结果的相对误差为–0.26%。改进后的方法准确度高、试剂能耗成本降低、分析时间缩短三分之二。     

分子筛催化剂-亚硫酸盐体系降解水中对乙酰氨基苯酚

过渡金属诱导亚硫酸盐体系产生硫氧自由基是一种新型的高级氧化技术,比常规的高级氧化过程(基于羟基自由基等)有更优越的性能.我们对过渡金属离子活化过硫酸盐和亚硫酸盐的硫氧自由基生成链式反应过程、自由基用于氧化有机污染物的国内外研究现状进行了大致总结,并以SBA-15介孔分子筛为载体,采用浸渍法制备Co-SBA-15固相催化剂,将此固相催化剂用于活化亚硫酸钠,产生强氧化性自由基,以此来降解制药废水中典型污染物对乙酰氨基酚(APAP).通过正交试验,探讨了pH、温度、钴离子与亚硫酸根的比值(简称钴硫比)、气体含氧量等参数对污染物降解效果的影响.对催化剂进行表征,对体系中产生的自由基类型进行检测,结合实验结果和文献资料对降解产物进行了分析,探究了APAP的降解原理.     

Validation of the simultaneous determination of methylprednisolone and methylprednisolone acetate in human plasma by high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatographic procedure was developed that accurately quantitates methylprednisolone (MP) and methylprednisolone acetate (MPA) in human plasma over the range 2.00-50.0 ng/ml. The internal standard, fluorometholone, was added to an aliquot of sodium fluoride-potassium oxalate-derived plasma. Samples were prewashed with hexane and extracted twice with methylene chloride. The extracts were dried with anhydrous sodium sulfate, centrifuged, and the organic layer separated and dried under nitrogen. The samples were reconstituted in mobile phase and washed an additional time with hexane before 100 microliters were injected onto a Beckman/Altex Ultrasphere ODS column with ultraviolet absorbance detection at 254 nm. Composition of the mobile phase was acetonitrile-water-glacial acetic acid (33:62:5, v/v/v). Calibration curves were obtained by unweighted, linear regression of peak-height ratios of MP (or MPA)/internal standard versus theoretical concentrations of MP or MPA using a Hewlett-Packard 3357 Laboratory Automation System. Extraction efficiencies for MP and MPA over the linear range were 86.4 and 84.7%, respectively. This method was successfully implemented for the analysis of specimens generated from a single-dose bioavailability and safety study for a new formulation of Depo-Medrol sterile aqueous suspension.     

MPEGMAA/G-570/DEM/AMPS新型酯类聚羧酸系减水剂的制备

以甲基丙烯酸聚乙二醇单甲醚酯600（MPEGMAA600）、 γ-甲基丙烯酰氧基丙基三甲氧基硅烷（G-570）、马来酸二乙酯（DEM）和2-丙烯酰胺-2-甲基丙磺酸（AMPS）为原料,过硫酸钾 硫酸亚铁为引发剂,合成了G-570/MPEGMAA/DEM/AMPS酯类聚羧酸系减水剂,其结构和组成经傅立叶变换红外光谱（FT-IR）和凝胶色谱（GPC）表征。通过正交实验确定最佳合成工艺为:MPEGMAA与DEM、 AMPS和G-570的摩尔比为1.0:1.0:2.0:0.4,过硫酸钾-硫酸亚铁总质量占聚合单体总质量的0.4%,于45 ℃聚合反应8 h,单体转化率为91.71%,水泥初始净浆流动度为225 mm。通过X-射线衍射（XRD）和热重（TG-DTG）分析对加入该减水剂的硬化水泥石微观结构进行了分析。结果表明：该减水剂链段中含有酯基、氨基、磺酸基、醚键、硅氧键等基团,平均相对分子质量分布集中,峰值大都集中在1.2~1.7万。同时,该减水剂可以延缓24 h内水泥水化。