顶空-气相色谱法测定橄榄油中六号溶剂残留量的不确定度评定

目的评定顶空气相色谱法测定橄榄油中六号溶剂残留量的不确定度。方法运用JJF 1059.1-2012《测量不确定度评定与表示》分析橄榄油中六号溶剂残留量测量过程中的不确定度来源,通过建立数学模型量化不确定度分量,计算合成不确定度和扩展不确定度。结果本方法的不确定度主要来源于标准溶液的配制。当橄榄油中六号溶剂残留量为123.6 mg/kg,扩展不确定度为8.8 mg/kg,六号溶剂残留量表示为(123.6±8.8)mg/kg(k=2)。结论该评定方法可为顶空气相色谱法对橄榄油中六号溶剂残留量的测量结果和方法的可靠性提供科学依据。     

探讨国标法测定食用油中溶剂残留量的影响因素

为提高顶空气相色谱法测定食用植物油中溶剂残留量的准确性,从基体油的选择和制备、内标物的选择、六号溶剂标准溶液的存放、平衡温度的影响、压榨法检出分析和计算方式的选择等方面,来探讨影响测定准确性的六个因素及防范、改进措施。在国标法GB 5009.262-2016的基础上,建立优化的测定食用植物油中溶剂残留量的顶空气相色谱法,减少测定误差,使食用植物油中残留溶剂量的测定更科学、准确。     

HGC和UV-HGC测定植物油中溶剂残留量的不确定度评定

通过顶空气相色谱法和超声振荡-顶空气相色谱法测定植物油中六号溶剂残留量,对测定过程中的不确定度来源进行分析,依据JJF 1059.1—2012《测量不确定度评定与表示》和CNAS-GL06《化学分析中不确定度的评估指南》中有关规定,建立数学模型,并对各分量进行量化,评定结果表明:影响检测结果不确定度的关键控制点为样品的前处理和标准曲线。     

HS-GC-MS法测定辣椒红油膏中有机溶剂残留

目的:建立测定辣椒红油膏中有机溶剂残留量的GC-MS分析方法。方法:采用顶空气相色谱-质谱法(HS-GC-MS)分析检测辣椒红油膏中己烷、丙酮、乙酸乙酯、甲醇及乙醇5种有机溶剂的残留量,并通过质谱对油膏中的有机溶剂进行定性分析。结果:方法的线性范围为0.02~5.00mg/kg,方法最低检出限≤0.035mg/kg,样品的加标回收率为91.9%~105.0%,RSD为1.6%~11.8%。结论:该方法简单、准确、可靠性强,适用于辣椒红油膏中有机溶剂残留量的测定。     

顶空气相色谱法测定辣椒红色素中溶剂残留

介绍了用顶空气相色谱法测定辣椒红色素中丙酮溶剂残留量的测定方法。采取取样１０ｇ,以无水乙醇配制标准的试验方法,得到满意的色谱分离图。本法的精密度、回收率及线性关系都较为理想,可作为测定辣椒红色素中丙酮残留量的测定方法。     

食用油中溶剂残留测定的若干影响因素分析

对影响食用油中残留溶剂顶空气相色谱测定的若干因素进行了探讨。样品性质、标准溶液选用、顶空样品制备、色谱分离模式以及定量计算方法的不同对定量结果影响显著；6号溶剂标准溶液的选用和配制是导致目前国家标准方法再现性差的主要因素。以残留溶剂中主要组分的单一试剂替代6号溶剂配制标准溶液可以提高目前测定方法的再现性，建议进行相关的规范化研究。     

番茄红素中丙酮产生的影响因素及控制措施探讨

利用顶空气相色谱-质谱联用对番茄红素挥发性物质的成分进行定性分析,建立了顶空气相色谱法检测番茄红素中丙酮的方法,该方法简单便捷,准确性高。以丙酮的含量变化为依据,考察氧气、放置温度及光照等因素对番茄红素中丙酮残留量的影响。结果表明:在番茄红素存储过程中采取抽真空隔绝氧气、控温5℃以内及避光放置的措施,可有效将番茄红素中丙酮的残留量控制在50 mg/kg以内。     

顶空气相色谱法在环境监测中的应用

本文对顶空气相色谱法的分类、工作原理、在环境监测中的应用及基质效应进行阐述,发现顶空气相色谱法能够有效避免冗长繁琐的前处理过程,为顶空气相色谱法在环境监测中的发展方向和应用前景提供参考。     

气相法测定番茄红素油树脂中两种溶剂残留量

目的建立测定番茄红素油树脂中乙酸乙酯和乙醇残留量的顶空气相色谱法。方法采用顶空气相色谱法。色谱柱为交联毛细管柱(Rtx-5,30 m×0.32 mm×0.25μm),FID检测器,载气为氮气,程序升温。结果乙酸乙酯和乙醇均能有效分离;在考察的浓度范围内均呈现良好的线性关系;平均加样回收率在81%~101%之间;精密度RSD均小于5.0%。结论经方法学验证,所建立的方法简便、准确、重复性好,可同时测定番茄红素油树脂中乙酸乙酯和乙醇的残留量。     

气相色谱法测定咖啡因中有机溶剂三氯甲烷的残留量

目的:建立原料药咖啡因中有机溶剂三氯甲烷残留量的测定方法。方法:采用顶空气相色谱法,电子捕获器,以超纯水为溶剂,色谱柱为石英毛细管色谱柱:PE ELITE-5MS(30m×0.25mm,膜厚0.25μm),载气为N2。结果:三氯甲烷测定方法的线性关系,重复性,检测限,定量限均达到了预定的分析要求,回收率在95.7%-98.6%之间。结论:本方法能快速准确的检测出有机溶剂三氯甲烷的残留量,能用于原料药咖啡因中残留溶剂的检测。     

Reducing the coumarin content of tonka bean extracts using supercritical CO2

By supercritical fluid CO₂ extraction of tonka beans a lipophilic top phase and a crystalline base phase were obtained. These were analysed by gas chromatography-mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC) and compared with an ethanolic extract of the same batch of tonka beans. It was shown that the three samples differed considerably in their composition and that the bulk of the main compound coumarin was present in the base phase of the CO₂ extraction.     

共轭亚油酸的分析

综述了共轭亚油酸的各种分析方法的最新进展 ,如气相色谱法、银离子高效液相色谱法、气—质联用和核磁共振。其中最简单、有效的分析方法是气相色谱法     

气相色谱法分析共轭亚油酸异构体

有许多种测定共轭亚油酸各异构体相对含量的方法 ,如气相色谱法、银离子高效液相色谱法、气质联用和核磁共振法等 ,其中气相色谱法最为简便快速。本研究选择气相色谱法用于共轭亚油酸各异构体的分析。结果表明 ,气相色谱法可用于共轭亚油酸中主要异构体的相对含量的测定     

对纺织品禁用偶氮染料检测方法的探讨

通过气相色谱 /质谱、液相色谱两种测定方法对三类芳香胺偶氮染料进行检测,发现按国家标准采用气相色谱 /质谱检测芳香胺时,对可能存在的异构体无法准确判定,而在高效液相色谱检测时可分离出异构体。建议除了采用气相色谱 /质谱法进行分析外,还需用高效液相色谱进行验证分析,从而对这方面的检测判断作一补充。     

胶体金试纸与气相色谱法检测毒死蜱结果相符率比较

目的通过研究胶体金法与气相色谱法在检测毒死蜱中的应用,证实胶体金试纸条在检测蔬菜中毒死蜱残留的可靠性。方法对比胶体金试纸半定量法和气相色谱定量法检测毒死蜱的结果。结果胶体金试纸条检测阴性样品得出的结果与气相色谱的结果符合率为100%,添加的阳性样品符合率也达到100%。添加的界限值样品的回收率达到96%。结论与气相色谱法相比较,胶体金试纸检测毒死蜱操作简便、观察直观、快速、省时,其特异性、敏感性较高,可作为蔬菜采摘前毒死蜱农药残留自我检测的手段。并可以此为基础建立一个不同于以前的毒死蜱监管模式。     

The West Falmouth oil spill after thirty years: the persistence of petroleum hydrocarbons in marsh sediments

The long-term fate of petroleum hydrocarbons in marsh sediments (West Falmouth, MA) contaminated in 1969 by the spill of the barge Florida was investigated. A 36-cm-long sediment core was collected in August 2000, and sediment extracts were analyzed by gas chromatography (GC) and comprehensive two-dimensional gas chromatography (GC x GC). The latter technique is capable of separating 1 order of magnitude more compounds than the former and was used to observe whether any compositional changes in the unresolved complex mixture (UCM) occurred. No evidence of petroleum residues was detected in the top 6 cm (0-6 cm) and the lower 8 cm (28-36 cm) of the core. However, the central sections 16-28 cm) were dominated by a UCM in the boiling range of n-C13-n-C25 alkanes, consistent with a No. 2 fuel oil source. The 12-14- and 14-16-cm sections had the highest concentrations of UCM approximately 8 mg g(-1)). These values are similar to concentrations observed shortly after the spill. Initial GC x GC analysis revealed that only the n-alkanes were completely degraded, and contrary to previous studies, pristane and phytane as well as numerous other branched alkanes are still present in the sediments. These results suggestthatatthis site hydrocarbon contamination will persist indefinitely in the sedimentary record.     

GC–MS-based metabolomics approach reveals metabolic variations between probiotics incorporated cow and goat milk yoghurt

The work is aimed at elucidation of metabolite profile of probiotic yoghurts prepared from cow milk (CPY) and goat milk (GPY) using gas chromatography–mass spectrometry-based untargeted metabolomics approach. A total of 192 metabolites including 49 differentially expressed metabolites (DEMs) were observed, wherein amino-acids, peptides and analogues constituted 41.93% of the metabolite sub-class. Acetic acid, glycine, Thr-Ala, octanoic acid, l -kynurenine and 2-amino adipic acid were among the top 15 DEMs. A significant relationship with seven key metabolic pathways including glycolysis, lysine degradation, purine metabolism, fatty acid biosynthesis, tryptophan metabolism, nicotinate and nicotinamide metabolism and glycine, serine and threonine metabolism has been established based on their impact values.     

气相色谱法测定饮料中的环已基氨基磺酸钠

介绍了气相色谱法测定饮料中甜蜜素的过程与方法。实践证明：该方法操作简单，检测速度快，检测率高。     

毛细管气相色谱法测定烟草中的亚硝胺

N-亚硝胺是烟草和卷烟烟气中一类重要的具有毒性和致癌性的化学成分。卷烟主流烟气中的N-亚硝胺一半左右直接来源于烟草,而其余则来源于抽吸过程中的热合成作用。我们研究开发了一种配备氮磷检测器的毛细管气相色谱方法来同时测定烟草中挥发性的亚硝胺(VNA)和烟草特有的亚硝胺(TSNA),主要过程包括将烟草样品在柠檬酸磷酸氢二钠缓冲液中超声波萃取,然后将萃取液在硅藻土层析柱上进行固相萃取,浓缩液用DB-5毛细管柱进行气相色谱分析。该方法具有操作简便快速,重复性好,无需专用仪器等特点,适用于各种烟草样品中亚硝胺的分析      

Identification and Aroma Impact of Volatile Terpenes in Moutai Liquor

Terpenes are very important impact aroma compounds in wines, and we discovered some trace volatile terpenes in Chinese liquors in this study. The volatile compounds in Kweichow Moutai liquor (Maotai) were enriched and isolated by liquid–liquid extraction and further separated by silica gel normal phase chromatography, then investigated by gas chromatography–olfactometry and gas chromatography–mass spectrometry. A total of 55 terpenes were finally identified in Moutai liquor by mass spectrum data from NIST11 a.L and wiley7n.L mass-spectral library, retention indices, and authentic standards. A majority of terpenes were reported in Chinese liquors for the first time. A headspace–solid phase microextraction coupled with gas chromatography–mass spectrometry was developed to determine terpenes in Moutai liquor and other aroma-type Chinese liquors. According to the gas chromatography–olfactometry and odor activity values analysis, terpenes were the important aroma compounds in Moutai liquor which led the liquor more elegant and delicate.