高效液相色谱法同时测定肉制品中的6种食品添加剂

建立了同时测定肉制品中化学性质差异较大的6种常用食品添加剂的高效液相色谱(HPLC)分析方法。根据6种添加剂(苯甲酸(钠)、山梨酸(钾)、糖精钠、安赛蜜、诱惑红和胭脂红)的化学性质,对HPLC分析条件进行了详细的优化。结果表明:以ZORBAX Eclipse Plus C18柱(150mm×4.6mm,5μm)为分析柱,以甲醇和20mmol/L醋酸铵溶液(pH为6.9)为流动相进行梯度洗脱,在235nm波长下进行检测,可以在18min内完成6种添加剂的同时测定。在高、低两个加标浓度下,样品的回收率为80.7%～94.4%,相对标准偏差(n=3)为2.0%～7.1%。结果表明,该方法快速、准确,能够同时分析测定肉制品中上述6种食品添加剂。     

Centurion — a revolutionary irradiator

The facility characteristics for irradiation of red meat and poultry differ significantly from those of medical disposables. This paper presents the results of the market requirement definition which resulted in an innovative conceptual design. The process and the “state of the art tools” used to bring this abstract idea into a proof of concept are presented.     

Dried blood spot on‐card derivatization: an alternative form of sample handling to overcome the instability of thiorphan in biological matrix

Thiorphan, the active metabolite of racecadotril, can undergo oxidation in biological matrices such as blood and plasma. In bioanalysis, a general approach for the stabilization of such a molecule is to derivatize the thiol group to a more stable thioether, often requiring complex handling procedures at the clinical site. In this research, the concept of dried blood spot (DBS) on‐card derivatization was evaluated to stabilize thiorphan. DBS cards were in‐house pre‐treated with 2‐bromo‐3′‐methoxyacetophenone and left to dry prior to blood spotting. Thiorphan was shown to be effectively derivatized to thiorphan–methoxyacetophenone once applied on the in‐house pre‐treated cards. Thiorphan–methoxyacetophenone was extracted by soaking a 6 mm DBS punch in methanol containing the internal standard (thiorphan–methoxyacetophenone‐D₅). Chromatographic separation was achieved on a Waters XBridge C₁₈ column with a gradient elution of 5 m m NH₄HCO₃ and methanol in 2.5 min and detection by ESI(+)/MS/MS. A linear (weighted 1/x²) relationship was obtained over a concentration range of 5.00–600.00 ng/mL. The assay met regulatory guidelines acceptance criteria for sensitivity, selectivity, precision and accuracy, matrix effect, recovery, dilution integrity and multiple stability evaluations. The DBS on‐card derivatization has shown to be an easy and reliable alternative form of sample collection for the quantification of thiorphan. Copyright © 2012 John Wiley & Sons, Ltd.     

Teil II: Ergebnisse bei der Bestrahlung einzelner Nahrungsmittelgruppen (Zusammenfassender Bericht)

Nachdem im ersten Teil dieser Arbeit [170] einige Grundprobleme der Nahrungsmittelbestrahlung behandelt wurden, sollen nun die bei der Bestrahlung wichtiger Nahrungsmittelgruppen erzielten Ergebnisse dargelet und eine Einschätzung der Entwicklungstendenzen versucht werden.     

气相色谱－质谱法测定赤鳞鱼肉中的脂肪酸

利用气相色谱质谱（ＧＣ／ＭＳ）电子轰击方法，对６种不同年龄和不同性别的赤鳞鱼肉中的饱和、不饱和脂肪酸（经甲酯化后）进行了测定，用色谱法作了定量，共鉴定出１８种脂肪酸。     

高效液相色谱-串联质谱法测定鸡肉产品中金刚烷胺残留量

应用高效液相色谱-串联质谱法测定鸡肉产品中金刚烷胺的残留量。样品经乙腈提取,以乙腈-水(3+7)溶液作为定容溶液。Phenomenex Kinetex C18色谱柱为分离柱,以不同体积比的0.1%(体积分数)甲酸溶液和乙腈为流动相进行梯度洗脱,采用电喷雾正离子源选择反应监测模式检测。采用基质匹配曲线校正。金刚烷胺的质量浓度在0.005~0.1mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为1.0μg·kg-1。以空白样品为基体进行加标回收试验,所得回收率在82.5%~94.0%之间,测定值的相对标准偏差(n=6)在6.3%~11%之间。     

禽肉中克球酚气相色谱微量快速测定法

对禽肉样品中克球酚药物残留采用微量化学法技术，以甲醇提取，氧化铝、阴离子树脂交换柱净化，乙酰化后，进行ＧＣ－ＥＣＤ毛细管色谱测定。经对肉鸡、填鸭、饲养山鸡进行添加回收率试验，方法回收率为８５．７％～９４．４％，变异系数为３．８％～７．７％，最低检出限为２．０ｎｇ／ｇ。     

Studies upon Qualification of Meat from Animals Irradiated and Contaminated with Radiocaesium

Abstract

The problem concerning qualification of food originated from animals irradiated and contaminated with ¹³⁷caesium appeared especially after the Chernobyl accident. So, it was a reason to undertake respective studies on 108 rabbits divided into three groups: group I – non-irradiated rabbits, group II – irradiated with a dose of 103 mCkg^?1 (400 R), group III – irradiated with a dose of 206 mCkg^?1 (800 R). All animals were contaminated intragastrically with an aqueous solution of ¹³⁷CsCl. After slaughter samples of the muscles were cured in 1, 3, 5, 10, and 15% brine or were cooked for 2 hrs. In the case of curing the radioactivities of meat and brine, and the concentrations of salt in cured meat were estimated after 7, 14, and 21 days. The radioactivities of cooked meat, broth, and condensed water vapour were estimated after 1 and 2 hrs. Taking into account the decrease of the radioactivities, duration of curing, and concentrations of salt in cured meat the optimum results were achieved when the meat from non-irradiated rabbits was cured for 7 days in 3% brine, and that of irradiated rabbits in 5% brine with regard to a lower stability of this meat. The decontamination effectiveness of cooking was similar in all examined rabbits. Radiocaesium penetrates into the brine or broth and escapes with water vapour thereafter.     

Rapid detection of doxycycline content in duck meat by using silver nanoparticles and alkylphenols polyoxyethylene enhanced fluorescence of europium complex

Doxycycline can coordinate with europium (III) to form europium (III)-doxycycline complex, which can emit the fluorescence characteristic peak of europium (III) at 617 nm in alkaline solution, and the experiment proved that the fluorescence intensity could be further enhanced in the presence of silver nanoparticles and surfactant alkylphenols polyoxyethylene. So this method was applied to detect doxycycline content in duck meat in this research. First, 390 and 617 nm were selected as the optimum excitation wavelength and optimum emission wavelength by three-dimensional fluorescence spectrometry, respectively. Second, the experimental conditions were optimized through single factor experiment. Lastly, the samples of doxycycline concentration range of 0.05–12 mg/L were analyzed under the optimum experimental conditions. A good linear relationship between the doxycycline concentration and the fluorescence intensity was obtained, and the determination coefficient and the root mean squared error of prediction were 0.9982 and 0.4363 mg/L, respectively. This research showed that it was feasible to achieve the rapid detection of doxycycline content in duck meat by using silver nanoparticles and alkylphenols polyoxyethylene enhanced the fluorescence of europium complex.     

A Smart Dental Floss for Biosensing of Glucose

The development of a simple directly wearable approach for the rapid, specific and sensitive determination of biomarkers is of great importance to a variety of biomedical applications. Dental floss can provide a unique device platform for sensing of oral biomarkers. We show here for the first time the development of a smart dental floss for biosensing of glucose. The sensor was made by painting carbon graphite ink and Ag/AgCl ink on dental floss. Via the immobilization of glucose oxidase, we show the detection of glucose with a detection range of 0.048 mM to 19.5 mM and a response time of about 2 min. It is expected that our results could provide new exciting opportunities for the development of various flexible smart sensing devices in oral health applications.