An analysis method for determining residual hexane in health functional food products using static headspace gas chromatography

A method for analyzing the contents of residual hexane in health functional food products was developed. The dissolving solvents in the health functional food products and the internal standard selected were N,N-dimethylacetamide and heptane, respectively. The analysis conditions for headspace-gas chromatography/flame ionization detection (HS-GC/FID) and headspace-gas chromatography/mass spectrometry (HS-GC/MS) were determined as 18 mL of headspace volume, 100°C of headspace oven temperature, and 30 min of equilibration time; a Durabond (DB)-624 column was selected for this analysis. To validate this method, which applies N,N-dimethylacetamide as a dissolving solvent, the limit of detection and limit of quantification (LOQ) values based on the HS-GC/FID and HS-GC/MS analyses results were found to be 0.10, 0.29 and 0.16, 0.47 mg/L, respectively. The recoveries and coefficient of variation (CV) obtained by HS-GC/MS were 96.39–119.86% and 0.04–1.25%, respectively, better than those obtained by HS-GC/FID. By applying the HS-GC/MS method, it was possible to analyze the content of the residual hexane in 60 different types of health functional food products.     

MONITORING LIPID OXIDATION AND ANTIOXIDANT EFFECTS OF PHOSPHOLIPIDS BY HEADSPACE GAS CHROMATOGRAPHIC ANALYSES OF RANCIMAT TRAPPED VOLATILES

Two of the most frequently used techniques to follow oxidation patterns of fats are headspace gas chromatography (HS-GC) and gas chromatography/mass spectrometry (GC/MS). The HS-GC technique offers the advantages of rapidity and multiple sample analyses, whereas GC/MS offers the advantages of GC separation coupled with the ability of MS to identify volatile compounds separated via GC. No previous information exists in the literature on the use of the volatiles trapped in water contained in the measuring vessel of the Rancimat and HS-GC to monitor lipid oxidation, as was the objective of this study. Oxidative secondary breakdown products of fish oil model systems trapped in water contained within the measuring vessel of the Rancimat were subjected to HS-GC analyses for quantitation of individual volatiles. Results from this study showed that oxidation induction time and products of oxidation can be monitored by the combined use of the Rancimat and HS-GC, and that trapped volatiles are representative of typical by-products of lipid oxidation and of oil type being examined. Addition of phospholipids (PL) to salmon and menhaden oils significantly influenced the production of volatile compounds. The molecular weights of the volatiles identified ranged from 30 to 212 daltons. The reproducibility of the method (std. dev. ≈ 2.04) was good but can be greatly improved through the use of a capillary column. PL having antioxidant activity generated lower concentrations of total volatiles than those found to be prooxidants.     

顶空气相分析技术及其应用

综述了现代顶空分析方法的分类及其应用。顶空气相色谱法(HS-GC)是测定样品中痕量易挥发化合物的重要分析方法,近年快速发展。是一项有着广阔应用前景的技术。     

Determination of acetaldehyde,methanol and fusel oils in distilled liquors and sakès by headspace gas chromatography

Food Science and Biotechnology - In this study, a headspace gas chromatography (HS-GC) method was carried out to determine the contents of acetaldehyde, methanol and fusel oils in distilled liquors...     

顶空-气相色谱法快速测定饮用酒类中甜蜜素含量

该实验建立了顶空-气相色谱（HS-GC）快速检测饮用酒类中甜蜜素的方法。样品经加热去除大部分乙醇和挥发性物质,样品提取液经衍生后,用顶空-气相色谱仪分析,以甜蜜素衍生产物环己烯为目标物,外标法定量。结果表明,当甜蜜素在饮用酒类中对应含量为1～100 mg/kg时线性关系良好（R2=0.998 9）,检出限和定量限分别为0.1 mg/kg和0.3 mg/kg,加标回收率为94.3%～107.1%,相对标准偏差（RSD）为2.5%～7.1%(n=6),精密度试验结果RSD为3.1%～4.9%。该方法简单、高效、环境友好、可靠、准确,可用于各种饮用酒类中甜蜜素的快速定量检测。     

顶空-气相色谱法测定葵花籽粕中六号溶剂残留量

目的建立葵花籽粕中的六号溶剂残留量的顶空-气相色谱(HS-GC)分析方法。方法样品葵花籽粕经N,N-二甲基甲酰胺(DMF)浸泡处理后顶空进样,通过实验优化样品前处理条件、顶空自动进样条件和气相色谱条件,确定最佳前处理方法、顶空平衡温度、平衡时间、气相色谱柱温度和分流比。结果六号溶剂各组分达到完全分离,线性良好,方法的检出限可达1.50 mg/kg,精确度为1.84%,样品加标回收率为96%~113%。结论本方法简便、快速、重现性好,为葵花籽粕中的残留溶剂提供了可靠的检测方法。     

全挥发顶空气相色谱法测定乙氧基含量

本文建立了一种全挥发顶空气相色谱法测定乙基纤维素乙氧基含量的方法。按照改进的蔡氏法(Zeisel),在顶空瓶中通过氢碘酸与乙基纤维素反应,使乙氧基转化为碘乙烷,反应结束后加碱液中和过量氢碘酸防止腐蚀进样器和色谱柱,随后抽取μL级样品全挥发顶空进样,进行气相色谱分析。以甲苯为内标物,采用内标法测定碘乙烷含量,从而计算得出乙基纤维素乙氧基含量。考察了平衡温度,平衡时间和样品量等影响因素,结果表明μL级样品(<40μL)在90℃的平衡温度下4min内可达到近乎完全挥发,碘乙烷和甲苯的质量比与它们的峰面积比呈良好的线性关系(r=0.9998,n=7),碘乙烷回收率98.9%(RSD=2.2%,n=6)。该方法操作简便,快速准确,可用于乙基纤维素的质量控制。     

Determination and quantitative analysis of acetoin in beer with headspace sampling-gas chromatography

A new method was developed for sensitive determination and quantitative analysis of acetoin in beer in our laboratory. Identification of derivative of acetoin (diacetyl) was carried out by headspace sampling-gas chromatography (HS-GC). The optimal equilibrium time of diacetyl was 32 min for the mixture of 4.5 mL iron reagent and 0.5 mL beer with the stirring of a shaker. As compared to 3 level calibrations, data obtained by 6 level calibrations were more accurate and consistent, and its correlation coefficient was between 0.99 and 0.999. The measuring precision for diacetyl was significantly improved to ?2% R.S.D (relative standard deviation) under the condition of HS (30 psi)/GC (22 psi) when compared to HS (30 psi)/GC (25 psi). Detecting precision of two level temperatures was ?1.5% R.S.D, which made all the detecting values existing between UCL (upper control limit) and LCL (lower control limit) in comparison with one level configuration. It was more reliable and suitable for the analysis of diacetyl to set up temperature configuration of two levels in HS-GC. Our results suggested that this method could be used successfully to analyse the concentration of acetoin in beer.     

甘氨酸与酿造酒中甲醇生成关系的研究

采用高效液相色谱法测定发酵液中甘氨酸含量和顶空气相色谱法测定酒中甲醇含量,研究了发酵液中甘氨酸与其生成甲醇的关系。结果表明,甘氨酸浓度在 0～0.9 g/L 范围内与酿造酒中甲醇生成呈线性关系,线性方程:Y=103.3X-4.5,甘氨酸转化率为 24.2 %。     

A Novel Method for Detection of Fusel Oil in Wine by the Use of Headspace Gas Chromatography

Fusel oils (FOs) are higher alcohols (including propanol, isobutanol, isoamylol, and active amyl alcohol), which affect the aroma profiles and flavor profiles of wine. A novel method for determination of FOs in lychee wine was developed using headspace gas chromatography (HS-GC). Results showed that 12% standard curve (SC) can be used to determinate the FOs of low alcoholic beverages, yet 40% SC can be used for high alcoholic beverages (e.g., brandy). Optimization of the parameters of equilibrium temperature at 50 °C was maintained for 30 min. The stabilized gas-liquid phase ratio of 3:1 for further research had no significant differences with others, which is caused by the distribution coefficient of K???100. The addition of sodium chloride (NaCl) decreased the partition coefficient of FOs markedly, and an inverse situation was observed for the extraction of FOs saturating at 1.25 g NaCl in 5 mL LW. Relative standard deviations (RSD) of reproducibility tests were in the range of 1.03–4.91%. Meanwhile, the mean recoveries of low, middle, and high concentration levels were 100.94, 103.2, and 96.74%, respectively. HS-GC was a stabilized, concise, and efficient method compared with the International Organization of Vine and Wine (OIV) method of OIV-MA-BS-14. These findings provide a foundation to determine higher alcohols of alcoholic beverages.     

HS-GC/MS method development and exposure assessment of volatile organic compounds from food packaging into food simulants

ABSTRACT

A simultaneous headspace-gas chromatography/mass spectrometry (HS-GC/MS) method was developed and validated to determine the migration of 12 volatile organic compounds (methanol, acetone, methylethylketone, ethylacetate, isopropylalcohol, benzene, toluene, ethylbenzene, xylene, cumene, propylbenzene, and styrene) from food contact materials into food simulants (water, 4% acetic acid, 50% ethanol, and n-heptane). The limits of detection and quantification were 0.007–0.201 mg L^?1 and 0.023–0.668 mg L^?1, respectively. The method was applied to 205 samples of paper/paperboard, polyethylene, polypropylene, polystyrene, and polyethylene terephthalate. The estimated daily intake (EDI) was calculated using the migration results. Exposure assessments were carried out to compare the EDI to the tolerable daily intake (TDI); the results indicated that the EDI of styrene represented only a small percentage (8.0%) of the TDI. This analytical method will be a useful tool to examine levels of various volatile compounds migrating from food packaging to food simulants using HS-GC/MS method.     

HS-GC法测定汽车内饰材料中有机挥发物量的不确定度评定

通过顶空-气相色谱(HS-GC)法对汽车内饰材料中的有机挥发物进行测定,对测定结果的不确定度来源进行分析,并对不确定度的各分量进行评定。结果表明,不确定度的主要来源为标准溶液配制和重复性测量样品。因此,在实际的分析过程中,应尽可能地提高实验人员的操作技能,确保测定结果的精确度和可靠性。     

顶空-气相色谱法测定丁酸梭菌发酵液中 短链脂肪酸含量

短链脂肪酸是丁酸梭菌生长代谢过程中的重要产物,是肠道内发生益生作用的主要物质之一。利用顶空-气相色谱(HS-GC)内标法测定短链脂肪酸,对该方法进行了方法学验证,并测定了丁酸梭菌在48 h发酵过程中短链脂肪酸含量的变化。结果表明:采用HS-GC可以很好地将各短链脂肪酸分离,且选用的内标物2-乙基丁酸与待测组分之间分离度较好;各短链脂肪酸标准品在0. 1～20. 0 mmol/L范围内,线性相关系数均大于0. 999,检出限为0. 01～0. 17 mmol/L,定量限为0. 02～0. 53 mmol/L,3 d内稳定性良好,样品加标回收率在88. 90%～108. 71%之间,符合测定要求;发酵液中检测到乙酸和丁酸两种短链脂肪酸,且含量随发酵时间延长逐渐增加,在40～48 h期间,乙酸和丁酸含量分别稳定在11. 9 mmol/L和14. 1 mmol/L左右。该方法无需复杂的前处理操作,准确度和精密度均符合要求,总分析时间较短,适用于丁酸梭菌发酵液中短链脂肪酸的快速检测。     

豆浆制备过程中大豆脂肪氧化酶的抑制与豆腥味量的关系

探讨大豆加工制备豆浆的过程中,有效抑制大豆脂肪氧化酶对降低豆腥味量的影响,为生产低含量豆腥味的豆浆提供理论与技术支持.通过抑制大豆脂肪氧化酶实验,即热水研磨大豆、热处理或化学处理大豆原料后再沸水研磨、大豆脱皮后隔氧研磨,对得到的豆浆样品采用静态顶空气相色谱质谱法测定13种豆腥味物质,比较定量数据获得最佳抑制脂肪氧化酶的...     

顶空-气相色谱法测定亚麻籽油中溶剂残留量的不确定度分析

目的分析顶空-气相色谱法测定亚麻籽油中的溶剂残留量的不确定度。方法应用因果图分析法分析溶剂残留量测量过程的不确定度来源,通过建立数学模型量化不确定度的各主要分量,计算合成不确定度和扩展不确定度。结果当亚麻籽油中溶剂残留量为20.3 mg/kg,扩展不确定为2.0 mg/kg(k=2)。影响检测结果测量不确定度的最主要因素为标准曲线拟合。结论通过分析评定测量不确定度,能够有效掌握实验测定结果的准确性和可信度,确保检验工作的质量。     

烟用纸张中挥发性成分稳定性评价方法研究

本研究使用顶空-气相色谱质谱联用(HS-GC/MS)方法定性定量分析商标纸、接装纸和内衬纸3类烟用纸张中挥发性有机化合物(VOCs),使用POWER BI气泡图深入剖析挥发性组分特征,并采用相似度算法建立各类纸张材料质控图予以有效评估烟用纸张质量稳定性。结果表明,以挥发性化合物的相对含量、检测频率和波动度3个维度深入分析各类烟用纸张中挥发性组分特征,可清晰聚焦纸张产品中影响质量稳定性的关键挥发性组分;接装纸相似度均值为0. 991,标准偏差仅为0. 014,产品波动度最小,质量均一性高于商标纸和内衬纸;相似度质控图可快速识别样品中挥发性组分整体波动性较大的异常样品,从而有效监控烟用纸张中VOCs全组分的质量稳定性。     

顶空-气相色谱法测定酒中甲醇

建立了顶空-气相色谱法测定酒中甲醇的分析方法。采用氢火焰离子化检测器,选择DB-624型毛细管色谱柱作为分离柱,程序升温,载气氮气流速为1.5m L/min,分流比为3:1。顶空进样器,顶空瓶加热温度为65℃,平衡时间为25min。结果表明,该方法测得甲醇的质量浓度在59.9~359.4mg/L范围内与峰面积呈线性关系良好,相关系数为0.9995。样品的加标回收率为95.0%~99.2%,最低检出限为0.005g/L。该方法快速、简便,准确度和灵敏度高,适合于酒中甲醇质量浓度的检测。     

Determination of toluene and other residual solvents in various food packaging materials by gas chromatography/mass spectrometry (GC/MS)

Levels of toluene and other residual solvents were evaluated in food packaging materials as a preventive action against hazard occurrence in foods via migration and to confirm food safety. Automated headspace sampling and gas chromatography/mass spectrometry (HS-GC/MS) were used to determine residual solvent levels in the food packaging materials. Correlation coefficients as calibration factors were over 0.999 and relative standard deviations (RSD) of repeatability were below 3.6%. Limits of quantification (LOQ) ranged from 0.001 to 0.01 mg/m². The levels of 7 residual solvents including toluene for potential migration from food packaging materials to food samples were below Korean regulatory limits.     

顶空气相法测定木质素中甲氧基含量

本研究介绍了一种顶空气相色谱法快速测定木质素甲氧基含量的方法,并以12种木质素模型化合物验证该方法的准确性和可靠性.在密闭的顶空样品瓶中加入木质素样品和0.5 mL氢碘酸,130℃下反应30 min,随后注入柠檬酸钠溶液中和样品,通过HS-GC测定样品瓶中的碘甲烷含量.结果 表明,丙酮抽提后云杉木粉(以Klason木质...     

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。