基于顶空固相微萃取(head space solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry,GC×GC-TOFMS)建立了一种准确定量...基于顶空固相微萃取(head space solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry,GC×GC-TOFMS)建立了一种准确定量白酒中氨基甲酸乙酯(ethyl carbamate,EC)的方法。实验对HS-SPME方法进行了优化,在酒精度12%vol、加NaCl 3 g、萃取温度70℃,萃取时间40 min的条件下,能够显著提高目标物的响应值。实验以D_(5)-氨基甲酸乙酯(D_(5)-EC)为内标,对不同浓度的样品溶液进行GC×GC-TOFMS定量分析。结果表明,EC在10~500μg/L范围内线性关系良好,回归系数(R^(2))>0.998,检出限为0.19μg/L,定量限为0.64μg/L,平均回收率为97.57%,精密度为8.66%。测定结果与国标方法相比无显著性差异(P>0.05)。该方法前处理简单,检测灵敏度更高,为白酒中EC自动化定量测定提供了新思路。展开更多
Qingke(highland barley)Baijiu is a special Chinese Baijiu which is mainly produced from Qinghai-Tibet Plateau.Since the pine board is used as the bottom of the fermentation pit,we deduced that the terpenoids and noris...Qingke(highland barley)Baijiu is a special Chinese Baijiu which is mainly produced from Qinghai-Tibet Plateau.Since the pine board is used as the bottom of the fermentation pit,we deduced that the terpenoids and norisoprenoids in pine board might be introduced into Qingke Baijiu.Thus,the terpenoids and norisoprenoids in Qingke Baijiu were investigated by headspace solid phase microextraction(HS-SPME)combined with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry(GC×GC-TOFMS).The results showed thatγ-terpinene(0.70-530.72μg/L),α-phellandrene(0.34-256.66μg/L),longicyclene(0-38.55μg/L),α-pinene(1.21-35.54μg/L)and limonene(0.93-23.69μg/L)were the top 5 terpenoids/norisoprenoids in Qingke Baijiu.Pulegone was detected and reported for the first time in Baijiu,and the concentrations in Qingke Baijiu were 0.78μg/L(fresh)and 3.90μg/L(7 years old).According to the principal component analysis(PCA)plot,young,aged,and retail Qingke Baijiu could be differentiated clearly.Fold change(FC)and t-tests analysis indicated thatβ-pinene,γ-terpinene,andα-selinene were the most different terpenoids/norisoprenoids between young and aged Qingke Baijiu,and longifolene was the most different terpenoids/norisoprenoids between base and retail Qingke Baijiu.The terpenoids and norisoprenoids,such as(E)-β-ionone,isoborneol andβ-cyclocitral,could be potential markers indicating the ageing process of Qingke Baijiu.展开更多
建立了全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)分析卷烟主流烟气中中性化学成分的方法。以较长的弱极性柱HP-5MS(50 m×0.2 mm i.d.×0.33μm)作为第一维柱,较短的薄液膜中等极性柱DB-17MS(1.7 m×0.1 mm i.d....建立了全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)分析卷烟主流烟气中中性化学成分的方法。以较长的弱极性柱HP-5MS(50 m×0.2 mm i.d.×0.33μm)作为第一维柱,较短的薄液膜中等极性柱DB-17MS(1.7 m×0.1 mm i.d.×0.1μm)作为第二维柱,对优质烟叶单料卷烟烟气的中性成分进行定性分析,经过人工纠错等分析初步鉴定出匹配度大于700的1 464种成分,重点讨论了中性香味羰基化合物全二维点阵的谱图特征,为烟气和复杂体系的深入研究提供了方法学基础。展开更多
文摘基于顶空固相微萃取(head space solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry,GC×GC-TOFMS)建立了一种准确定量白酒中氨基甲酸乙酯(ethyl carbamate,EC)的方法。实验对HS-SPME方法进行了优化,在酒精度12%vol、加NaCl 3 g、萃取温度70℃,萃取时间40 min的条件下,能够显著提高目标物的响应值。实验以D_(5)-氨基甲酸乙酯(D_(5)-EC)为内标,对不同浓度的样品溶液进行GC×GC-TOFMS定量分析。结果表明,EC在10~500μg/L范围内线性关系良好,回归系数(R^(2))>0.998,检出限为0.19μg/L,定量限为0.64μg/L,平均回收率为97.57%,精密度为8.66%。测定结果与国标方法相比无显著性差异(P>0.05)。该方法前处理简单,检测灵敏度更高,为白酒中EC自动化定量测定提供了新思路。
基金financially supported by the National Key R&D Program of China (2016YFD0400500)
文摘Qingke(highland barley)Baijiu is a special Chinese Baijiu which is mainly produced from Qinghai-Tibet Plateau.Since the pine board is used as the bottom of the fermentation pit,we deduced that the terpenoids and norisoprenoids in pine board might be introduced into Qingke Baijiu.Thus,the terpenoids and norisoprenoids in Qingke Baijiu were investigated by headspace solid phase microextraction(HS-SPME)combined with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry(GC×GC-TOFMS).The results showed thatγ-terpinene(0.70-530.72μg/L),α-phellandrene(0.34-256.66μg/L),longicyclene(0-38.55μg/L),α-pinene(1.21-35.54μg/L)and limonene(0.93-23.69μg/L)were the top 5 terpenoids/norisoprenoids in Qingke Baijiu.Pulegone was detected and reported for the first time in Baijiu,and the concentrations in Qingke Baijiu were 0.78μg/L(fresh)and 3.90μg/L(7 years old).According to the principal component analysis(PCA)plot,young,aged,and retail Qingke Baijiu could be differentiated clearly.Fold change(FC)and t-tests analysis indicated thatβ-pinene,γ-terpinene,andα-selinene were the most different terpenoids/norisoprenoids between young and aged Qingke Baijiu,and longifolene was the most different terpenoids/norisoprenoids between base and retail Qingke Baijiu.The terpenoids and norisoprenoids,such as(E)-β-ionone,isoborneol andβ-cyclocitral,could be potential markers indicating the ageing process of Qingke Baijiu.
文摘建立了全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)分析卷烟主流烟气中中性化学成分的方法。以较长的弱极性柱HP-5MS(50 m×0.2 mm i.d.×0.33μm)作为第一维柱,较短的薄液膜中等极性柱DB-17MS(1.7 m×0.1 mm i.d.×0.1μm)作为第二维柱,对优质烟叶单料卷烟烟气的中性成分进行定性分析,经过人工纠错等分析初步鉴定出匹配度大于700的1 464种成分,重点讨论了中性香味羰基化合物全二维点阵的谱图特征,为烟气和复杂体系的深入研究提供了方法学基础。
