卷烟主流烟气中苯并[a]芘的HPLC测定

先用乙醇 +乙醚混合溶剂萃取卷烟烟气总粒相物 (TPM) ,再用中性氧化铝柱层析 ,然后 ,利用配有ODS -C18色谱柱的高效液相色谱仪 ,在以 90 %甲醇 + 10 %水为流动相 ,流速为 1mL min ,激发波长 2 86nm和发射波长 4 30nm的条件下测定了TPM中的苯并 [a]芘含量。苯并 [a]芘的回收率≥ 91.2 % ,方法的RSD <5 %。并采用该方法测定了 10种不同焦油量卷烟主流烟气中的苯并 [a]芘含量。结果表明 ,就所测定的卷烟而言 ,①在焦油量相近的情况下 ,混合型卷烟烟气中的苯并 [a]芘含量较烤烟型卷烟的低 8.2 9%～ 19.5 9% ;②无论是烤烟型还是混合型卷烟 ,随着卷烟焦油量的降低 ,虽然焦油中的苯并[a]芘总量明显降低 ,但单位量焦油中的苯并 [a]芘含量却明显增大。     

高效液相色谱法测定卷烟主流烟气中的苯并[a]芘

为了测定卷烟主流烟气中苯并[a]芘,考察了萃取条件、弗罗里硅土净化条件和色谱分离条件,建立了测定卷烟主流烟气中苯并[a]芘的高效液相色谱-荧光检测法,并采用该方法和国标法测定了肯塔基参考卷烟3R4F和国内参比烤烟以及国内50个牌号卷烟样品烟气中的苯并[a]芘。结果表明:①用环己烷超声萃取40 min效果较好;②用Agilent ZORBAX Eclipse PAH作色谱柱,乙腈和水为流动相,梯度洗脱,流速2.0 mL/min,30 min内苯并[a]芘色谱峰可以和杂质峰有效分开;③该法的平均回收率在98.13%～101.36%之间,RSD在1.29%～4.32%之间;④该方法的测定结果与国标法较为一致,二者不存在显著性差异。该方法适合卷烟主流烟气中苯并[a]芘的检测。     

高效液相色谱法测定反应香精中的3,4-苯并□

建立高效液相色谱测定反应香精中3,4-苯并芘的方法,考察前处理方法及色谱条件对实验回收率的影响,确定了C18固相萃取柱为前处理工艺,萃取剂为甲醇,色谱流动相为甲醇∶水=90∶10,流速为1.0 mL/min,DAD检测波长为UV-290 nm.测定反应样品不合3,4-苯并芘,加标实验回收率为76.66%～79.44%.相对平均偏差为1.28%.     

内标校准液相色谱荧光法测定食用油中苯并（a）芘

采用内标苯并（b）屈校正,建立了正相固相净化-反相液相色谱-荧光分光光度法测定食用油中苯并（a）芘的方法。正相Plus Silica固相萃取柱作为净化柱,反相C18柱作为分离柱。以苯并（b）屈作为内标,测定了苯并（a）芘的校正因子。使用本方法,苯并（a）芘在液态食用油和固态食用油中的检出限分别为0.01和0.03μg/kg。苯并（a）芘在不同食用油回收率在83%～108%之间,方法的日内精密度和日间精密度分别小于7.7%和13.2%。     

二甲亚砜提取—冷冻离心净化测定食品中苯并[a]芘及苯并[e]芘

建立以二甲基亚砜作为提取溶剂,冷冻离心提取净化食品中的苯并[a]芘和苯并[e]芘,高效液相色谱—荧光法检测的方法。替代传统的固相萃取小柱净化方式,能更快速、高效、准确检测食品中苯并[a]芘和苯并[e]芘的含量。2种目标物在0.5~1 000 ng/mL范围内呈现良好线性关系,在1~100 ng/g添加量下,回收率为89.0%~91.3%,相对标准偏差为1.19%~1.29%;仪器检出限为0.01 ng/mL,植物油脂方法检出限为0.05 ng/g,肉制品和动物油脂方法检出限为0.02 ng/g。该方法测定动植物油脂和肉制品中的苯并[a]芘和苯并[e]芘方便、快捷,适用于批量化检测。     

荧光光度法测定卷烟烟气中3,4-苯并[α]芘

改进了荧光光度法测定卷烟烟气中3，4－苯并[α]芘（B[α]P）的方法。烟气焦油中稠环芳烃用石油醚－二氯甲烷（95＋5）混合液振荡提取，用咖啡因分离出稠环芳烃，纸层析分离3，4－苯并[α]芘，于激发波长383nm，发射波长405nm条件下，在发射波长400－410nm，测得400、405和410nm处苯并[α]芘的相对荧光强度。通过标准曲线计算出苯并[α]芘的含量。平均回收率为92．5％，RSD为7．20％。运用本法对几种不同透气度盘纸卷制的卷烟气中的苯并[α]芘含量进行测定，获得理想结果。     

Determination of benzo[a]pyrene in some Spanish commercial smoked products by HPLC-FL

In order to investigate the levels of the potently carcinogenic benzo[a]pyrene (BP), 31 samples of smoke foods were analysed. The samples tested included five samples of meat products, three samples of cheese and 22 samples of fish. A liquid chromatographic method was developed using a fluorescence detector. BP was found in 74% of the samples analysed. The levels varied from not detected to 2.46 mug/kg. Only one sample showed a BP level above 1 mug/kg, the maximum level that the EU intends to set for smoked foods.     

四氮杂杯[2]芳烃[2]三嗪键合硅胶固相萃取/HPLC-MS/MS法测定家兔血浆中的TSNAs

为了准确测定家兔血浆中的烟草特有N-亚硝胺(TSNAs),制备了四氮杂杯[2]芳烃[2]三嗪键合硅胶(NCS)固相萃取柱,并通过对NCS固相萃取、色谱及质谱条件的优化,建立了测定家兔血浆中的N-亚硝基降烟碱(NNN)、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮(NNK)、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁醇(NNAL)、N-亚硝基新烟草碱(NAT)和N-亚硝基假木贼碱(NAB)5种TSNAs的NCS固相萃取/HPLC-MS/MS方法.结果表明:NCS固相萃取柱对家兔血浆中5种TSNAs的萃取效率优于商品化的C18固相萃取柱;5种TSNAs的检测限为0.0092～0.0590 ng/mL,回收率和相对标准偏差(RSD)分别为90.1％～113.3％和0.95％～7.22％.该方法简单、准确,适合于家兔血浆中TSNAs的检测.     

Determination of the level of benzo[a]pyrene in fatty foods and food supplements

A routine method was developed for the quantification of benzo[a]pyrene (BaP) in edible oils and food supplements. BaP is often taken as an indicator of the presence of polycyclic aromatic hydrocarbons. The method consists of on-line liquid chromatography clean-up followed by injection to an HPLC system with fluorescence detection. The method has good performance characteristics and gave good results in proficiency tests. From 2002 to 2004, about 1350 samples of oils and food supplements were analysed using this method to test the level of BaP. About 20% of the edible oils contained more than 1.2 µg kg^-1 BaP (which is the limit applied by the Dutch Food and Consumer Product Safety Authority until 1 April 2005, and includes measurement uncertainty). In the case of food supplements, more then 30% contained too high levels of BaP, ranging from 1.2 to 135 µg kg^-1.     

高效液相色谱-内标法测定卷烟烟气粒相物中的B(a)P

研究了使用1,2-二(9—蒽基)乙烷作为内标,高效液相色谱—荧光检测器(HPLC-FD)法测定卷烟烟气粒相物中B(a)P的方法。在捕集了卷烟烟气的剑桥滤片上加入内标,经超声萃取后用SPE小柱进行纯化。萃取液浓缩重组溶剂后直接进样分析。优化了流动相并选择了梯度洗脱使得B(a)P与内标物完全分离。使用该方法测定商品卷烟,方法平均回收率为(94±1.2)%,方法检测限是0.9ng/mL,相对标准偏差为(3.1～3.8)%。     

基于磁性共价有机骨架对烤肉中苯并[a]芘的检测

采用快速简单的共沉淀法合成磁性共价有机骨架材料,并通过傅里叶变换红外光谱、透射电镜对其进行表征.通过优化吸附剂用量、萃取时间、解吸溶剂、解吸时间和解吸体积等条件,建立了磁固相萃取-高效液相色谱法测定烤肉中苯并[a]芘(Benzo[a]pyrene,BaP)的新方法.该方法的线性范围为0.5～100.0 μg/L(R2=...     

[PSI] and [URE3] as yeast prions

[URE3] is a non-Mendelian genetic element that mimics recessive mutations in the chromosomal URE2 gene making cells derepressed for nitrogen catabolic enzymes. [PSI] is a non-Mendelian enhancer of readthrough of translational termination similar in its effects to some mutations in the chromosomal SUP35 gene. Three lines of evidence led to the proposal⁷⁵ that both [URE3] and [PSI] are prions, infectious proteins analogous to the scrapie agent mediating transmissible spongiform encephalopathies of mammals. (1) Both [PSI] and [URE3] are reversibly curable. (2) [PSI] propagation requires SUP35 and [URE3] propagation requires URE2 with recessive chromosomal mutants having the same phenotypes as the presence of the respective dominant non-Mendelian element. (3) Overproduction of Sup35p and Ure2p increases the frequency of cells acquiring [PSI] or [URE3], respectively.     

Determination of benzo[a]pyrene in camellia oil via vortex-assisted extraction using the UPLC-FLD method

In this paper, vortex-assisted extraction using the ultraperformance liquid chromatography analysis method was performed to determine benzo[a]pyrene in camellia oil. Optimum results were obtained when 0.5 g of oil sample was used followed by vortex-assisted extraction for 10 min with 25 mL of acetonitrile. Chromatographic separation was performed on an Agilent ZORBAX Eclipse Plus C₁₈ column (2.1mm×100mm, particle size 1.8 μm). The optimum mobile phase comprised 70% acetone and 30% water. The detection limit of benzo[a]pyrene was 0.2 μg/kg. The recoveries were in the range of 81.0–97.0%. The proposed method was simple and fast, and it provided high throughput in the determination of benzo[a]pyrene in an oil matrix sample.     

卷烟烟气中苯并[a]芘测定方法研究

为准确测定卷烟烟气中的苯并[a]芘(BaP),建立了2种测定卷烟烟气中BaP的方法———高效液相色谱法和气质联用法。优化了2种方法的前处理过程、仪器分析条件,并测定了其重复性、回收率和检测限。通过2种分析方法的比较,确定了环己烷萃取、硅胶柱固相萃取纯化和气相色谱-质谱法定量检测BaP含量的标准分析方法。该法BaP的检测限为1.44ng/mL,回收率为99.45%～102.40%,CV为2.77%。采用该法测定了国内外81种卷烟烟气中的BaP含量,并对这些卷烟烟气中BaP含量分布进行了探讨。     

Determination of aluminum in foods]

In connection with studies on the changes of functional properties of food constituents (e. g. solubility of proteins) by means of aluminium compounds, the elaboration of an appropriate method for the quantitative determination of aluminium has been necessary. The organic samples are mineralized with 80% perchloric acid; in case of fat-containing foods, after fat removal. After reaction with aluminon (ammonium salt of aurin tricarboxylic acid), aluminium is determined photometrically at 530 nm. The limit of detection lies between 1 and 2 ppm; the recovery rate is 103%; the standard deviation is +/- 10%. The determination (without mineralization) requires about 1 hours. The authors analyzed, inter alia, milk (1.2--1.7 ppm A1), fat cheese (9 ppm), micora (4 ppm), aluminium-stabilized protein texturates (300--1500 ppm).     

Determination of 14C residue in eggs of laying hens administered orally with [14C] sulfaquinoxaline

Ten layer hens were dosed for 5 consecutive days with 6.2 mg kg^-1 [¹⁴C] sulfaquinoxaline (SQX). Eggs were collected from the hens during the 5-day dosing period and during a 10-day post-dose withdrawal period. Egg yolk and albumen were separated and assayed for total radioactive residues (TRR) using a combustion oxidizer and liquid scintillation counting techniques. Significant amounts of radioactivity were detected on the second day of dosing (greater than 24 h after the initial dose) in both egg yolk and albumen. First eggs were collected about 8 h after dosing; the second-day eggs were collected during 8-h period after the second dose. Radioactive residues reached a maximum on the fifth day of dosing in albumen, whereas on the second day of withdrawal in egg yolk, the peak TRR levels in albumen were about threefold higher than in yolk. Thereafter, the TRR levels declined rapidly in albumen and were detectable up to withdrawal day 6, whereas the TRR levels in egg yolk declined more slowly and were detectable up to withdrawal day 10. High-performance liquid chromatography analysis indicated that the parent drug sulfaquinoxaline was the major component in both the egg albumen and yolk. Additionally, this work suggests that egg yolk is the appropriate matrix for monitoring SQX residues     

Determination of riboflavin in foods]

The author examined the conditions under which the lumiflavin method may be used for the determination of riboflavin. Neither the presence of various cations and anions, nor the presence of cellulose, starch and protein exerted any effect on the oxidation with potassium permanganate. The riboflavin losses increased when potassium permanganate was used at a concentration of more than 2%. The losses were considerably lower it the purification of the extracts by means of potassium permanganate was performed after photolysis. The most favourable results were obtained when the extracts were shaken with chloroform prior to photolysis to eliminate interfering substances. These findings were corroborated by comparative analyses on 3 standard samples.     

气质联用法测定卷烟侧流烟气中苯并[a]芘

建立了采用气相色谱/质谱联用法分析卷烟侧流烟气中苯并[a]芘的分析方法.该方法使用配有鱼尾罩的侧流吸烟机抽吸卷烟,鱼尾罩附着的苯并[a]芘采用甲醇洗脱,洗脱液中的甲醇在N2保护下加热至80℃挥发完,然后加入捕集了侧流烟气总粒相物的玻璃纤维滤片,采用环己烷超声萃取苯并[a]芘,萃取液苯并[a]芘浓度采用气相色谱/质谱联用...     

气相色谱-串联质谱法同时检测卷烟主流烟气中的苯并[a]芘和NNK

建立了同时测定卷烟主流烟气中苯并[a]芘(Ba P)和4-(N-甲基-N-亚硝氨基)-1-(3-吡啶基)-1-丁酮(NNK)的气相色谱-串联质谱(GC-MS/MS)方法。用剑桥滤片捕集卷烟主流烟气粒相物后再用甲苯进行振荡萃取,萃取液经过基质分散固相萃取净化及氮吹浓缩后采用DB-35MS色谱柱分离、多反应监测(MRM)模式分析,内标法定量。结果表明:①NNK和BaP的定量限、加标回收率、相对标准偏差(RSD)分别为0.36和0.29 ng/支,78.8%~95.5%和101.6%~106.6%,2.3%~15.4%和2.9%~14.4%。②与标准方法相比,该方法前处理简单,可实现两种目标物的同时测定。③采用该方法与现有标准方法对27个卷烟的检测结果显示两组数据的一致性较好,无显著性差异。该方法操作简单、结果准确,适用于同时分析卷烟主流烟气中NNK和BaP的释放量。