离子排斥色谱法测定纺织品中丙烯酰胺

采用离子排斥色谱法测定纺织品中丙烯酰胺的残留量。以水为溶剂提取样品中的丙烯酰胺,提取液过滤后经离子排斥色谱分离测定丙烯酰胺含量。色谱条件为:IonPac ICE-AS1柱(250mm×4.0mm,5μm);流动相为乙腈和10mmol/L甲酸水溶液;检测波长202nm;流速0.15mL/min。该方法在20～1 000μg/L浓度范围内具有良好线性关系,相关系数为0.9998,方法检测限为0.4mg/kg,回收率在93.9%～103.0%之间,相对标准偏差在1.85%～3.75%之间。     

离子色谱法同时测定蛋白胨中5种阴离子

目的建立离子色谱法同时测定微生物培养基蛋白胨中5种阴离子——氯离子Cl~-、硫酸根离子SO_4~(2-)、正磷酸根离子PO_4~(3-)、三偏磷酸根离子P_3O_9~(3-)和碘离子I-含量的方法。方法样品用10mmol/LNaOH溶液溶解浸提,经固相萃取柱OnGuard II RP柱和Na柱去除有机物及阳离子,净化后直接用于目标离子的测定。色谱分离选用强亲水性阴离子交换柱(IonPac AS11, 4.0 mm 250 mm),以KOH为流动相进行梯度洗脱,流速为1 mL/min,于抑制电流为174 mA下用电导检测器检测。结果在35 min内完成5种阴离子的分离分析。该方法测定5种阴离子相关性好(r0.999),线性范围宽,检测限均1μg/mL,蛋白胨样品中目标物的平均加标回收率为99.6%～108.4%(n=9)。结论该方法实现了5种阴离子的同时测定,简单高效,灵敏度高,用于实际样品测定结果满意。     

二维超高效液相色谱-三重四极杆/复合线性离子阱质谱联用法快速测定水产品及其制品中河豚毒素

建立中心切割二维超高效液相色谱-三重四极杆/复合线性离子阱质谱联用法快速测定水产品及其制品中河豚毒素的方法。样品经0.2%乙酸溶液提取,提取液用0.2%乙酸溶液稀释和过滤后直接进样分析。使用2种不同性质固定相的色谱柱(Hypercarb PGC和Acquity BEH Amide)通过二位六通切换阀连接,样品先经第1维起反相色谱分离作用的多孔石墨碳色谱柱Hypercarb PGC(2.1 mm×100 mm,3μm)分离,再将分离出含有河豚毒素的流分切割至捕集柱XBridge BEH Amide guard column(起亲水色谱分离作用的酰胺色谱柱)(4.6 mm×10 mm,2.5μm)中进行捕集,然后再将捕集柱切换至第2维的流路中,洗入第2维起亲水色谱分离作用的酰胺色谱柱Acquity BEH Amide(2.1 mm×100 mm,1.7μm)中进行分离,电喷雾正离子模式多离子监测触发的增强子离子扫描方式检测,溶剂标准外标法定量。水产品中河豚毒素的平均加标回收率为82.3%～95.4%,相对标准偏差在2.1%～14%之间(n=6),方法的定量限(R_(SN)=10)为0.002 mg/kg。本法操作简单、灵敏度高、选择性好,可应用于水产品及其制品中河豚毒素的检测。     

离子色谱法测定液体乳中硫氰酸根

建立测定液体乳中硫氰酸根的离子色谱方法。采用Metrosep A supp5阴离子色谱柱(4.0×150 mm,5μm),以7.0mmol/L Na2CO3+1.0 mmol/L NaHCO3+10%丙酮为淋洗液,样品用3%乙酸溶液沉淀蛋白质,经离心处理后,过0.22μm滤膜,经色谱柱将硫氰酸根与其他阴离子分离,通过电导检测器检测。本方法硫氰酸根浓度在0.10~10.0 mg/L范围内线性良好,相关系数为0.9994,回收率为94.0~102%,RSD为0.96~2.01%,检出限为0.3 mg/kg。本文建立了科学、快速、准确测定液体乳中硫氰酸根含量的方法,简化样品处理过程,提高检测工作效率。     

超高效液相色谱–串联质谱法测定特殊医学用途配方食品中胆碱含量

目的 建立超高液相色谱–串联质谱法(ultra high performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)测定配方食品中胆碱的分析方法, 为胆碱及其制剂的含量测定提供参考。方法 样品中的胆碱经过盐酸水解, 提取后, 以0.1%甲酸-甲醇作为流动相经kinetex 5u XB-C18柱(4.6 mm×100 mm, 5 μm)梯度洗脱分离, 流速0.45 mL/min, 采用UPLC-MS/MS在正离子模式下检测, 外标法定量。结果 在优化实验条件下, 测得胆碱在浓度为0.1~0.5 μg/mL有良好线性关系, 线性相关系数为0.9993。方法的回收率为96.1%~103.4%, 检出限为2.27 mg/100 g。结论 超高效高效液相色谱–串联质谱法简单快速、灵敏度高、准确性强, 适用于特殊医学用途配方食品中胆碱的分析。     

高效液相色谱-蒸发光检测器法测定鸡蛋中卵磷脂的含量

建立高效液相色谱-蒸发光检测器法测定鸡蛋中卵磷脂含量的分析方法。以Intersil SIL-100A 色谱柱（4.6 mm×100 mm, 5 μm）为分离柱,甲醇-乙腈-异丙醇为流动相,流速0.8 mL/min,柱温30 ℃,以空气作为雾化气,气体流速1.7 L/min,漂移管温度45 ℃。结果表明,磷脂酰胆碱和磷脂酰乙醇胺在0.052～1.031 mg/mL和0.041～0.823 mg/mL范围内与峰面积有良好线性关系,鸡蛋中磷脂酰胆碱和磷脂酰乙醇胺精密度的相对标准偏差（RSD）分别为2.55%和2.50%,加标回收率分别为93.0%～101.8%和96.7%～106.7%,表明该方法重复性好、准确度高。测定已知磷脂含量的鸡蛋样品,结果显示蒸发光检测器的测定结果比紫外检测器测定结果更符合真值,实验建立的方法可以准确定量鸡蛋中卵磷脂的含量,是测定蛋黄卵磷脂成分的理想方法。     

微波水解/超高效液相色谱-串联质谱法快速 测定乳粉中的胆碱和左旋肉碱

目的利用微波消解技术对乳粉样品进行水解,释放结合态的胆碱和左旋肉碱,优化乳粉中胆碱和左旋肉碱的微波水解快速提取方法以及超高效液相色谱-串联质谱(UPLC-MS/MS)检测的条件参数。方法乳粉样品用温水复溶后,取适量样品加入1.5 mol/L的盐酸溶液,100℃微波消解10 min后调节pH至中性,稀释后以HSS T3 UPLC色谱柱和0.1%甲酸水溶液(V:V)-乙腈进行梯度洗脱分离,以串联质谱的多反应监测模式检测,内标法定量。结果方法线性范围1.00~500μg/L,相关系数(r~2)0.998以上,胆碱和左旋肉碱定量限分别为0.24mg/100 g和0.63 mg/100 g,3个添加水平的回收率分别为93.6%~102%,相对标准偏差为1.9%~4.0%。日间精密度分别为2.7%和4.1%。结论本方法分析速度快、灵敏度高、重复性好,与现有技术对比,该方法通过微波技术辅助水解,缩短了样品处理的时间,适用于乳粉中的胆碱和左旋肉碱的检测。     

HPLC/FLD测定聚酯纤维纺织品中9种非离子荧光增白剂

建立了纺织品中DT、SWN、OB、KSN、ER-Ⅰ、ER-Ⅱ、KCB、OB-Ⅰ、OB-Ⅱ9种非离子荧光增白剂(FWAs)的前处理方法以及高效色谱荧光检测(HPLC/FLD)方法。样品经二甲苯提取、浓缩、定容后,进行HPLC/FLD定性定量分析。采用PhenomenexGemini 5u C18(150 mm×4.6 mm,5μm)色谱柱进行分离,以乙腈-2.5 mmol/L乙酸铵溶液为流动相,梯度洗脱。9种非离子FWAs的相关系数均不小于0.999 3,定量下限(LOQs,S/N=10)为0.70~0.95 mg/kg。不同添加水平下,9种非离子FWAs的回收率为83.0%~100%,相对标准偏差(RSDs)为4.0%~8.8%。该方法简单、灵敏度高,具有一定的实际应用价值。     

液相色谱-串联质谱法测定水果中6种植物生长调节剂残留量

目的研究同位素内标-液相色谱-串联质谱测定水果中6种植物生长调节剂的方法。方法样品经含1%乙酸的乙腈提取,采用Welch Xtimate C18色谱柱(2.1 mm×100 mm,3μm),乙腈-0.01%氨水(含2 mmol/L乙酸铵)为流动相,梯度洗脱,多反应离子监测(MRM)模式,分段ESI+与ESI-扫描方式检测。结果 0.6、10和50μg/kg三个浓度的样品加标试验,回收率为80.1%~115.0%,相对标准偏差为4.3%~9.9%,定量限和检出限分别在0.2~4.0和0.06~1.5μg/kg。结论建立的分析方法简便、准确、灵敏,满足食品中农药最大残留限量要求。     

浓缩石榴汁中熊果苷的超高效液相-串联质谱检测方法研究

建立了浓缩石榴汁样品中熊果苷含量测定的固相萃取-超高效液相-串联质谱测定方法。样品用水稀释,HLB和氨基固相萃取柱净化,采用BEHAmide色谱柱(100mm×2.1mm,1.7μm)分离,以乙腈和水梯度洗脱,多反应监测模式测定,定量离子对为m/z271.2>108.0,定性离子对为m/z271.2>160.9,外标法定量。熊果苷的检测限为0.006mg/kg,在0.004～0.2mg/L浓度范围内,熊果苷的线性相关系数为0.9994,熊果苷的加标回收率均在80.6%～108.1%范围内,相对标准偏差均低于8.3%。该方法样品净化效果良好,检测简便、快速、准确,能够满足浓缩石榴汁中熊果苷含量测定和定性确证的要求。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.