Evaluation of analysis of cholesterol oxidation products and heterocyclic amines in duck and their formation as affected by roasting methods

Roast duck, a popular meat commodity in Asian countries especially Taiwan and China, can produce many types of toxic compounds such as cholesterol oxidation products (COPs) and heterocyclic amines (HAs). The objectives of this study were to evaluate analysis of COPs and HAs in duck by GC–MS and UPLC-MS/MS respectively, and study their formation as affected by roasting methods including traditional oven, fan oven and superheated steam oven. Results showed that both high precision and accuracy was attained by using the QuEChERS method with reduced separation time of 14 min for 7 COPs and 4.5 min for 21 HAs by GC–MS and UPLC-MS/MS, respectively. The duck meat roasted in both superheated steam oven and traditional oven generated significantly higher levels of total COPs than fan oven, while for total HAs, both traditional oven and fan oven produced significantly higher levels than superheated steam oven. Compared to roast duck skin, a much higher level of total COPs was shown in roast duck meat, while a reversed tendency was shown for total HAs. Furthermore, the correlation between formation of COPs and HAs in roast duck skin showed no significant correlation (p > 0.05) for traditional oven, fan oven and superheated steam oven, while in roast duck meat, only traditional oven showed significant correlation (p < 0.05). However, by taking both duck skin and meat into account, superheated steam oven produced the lowest level of total HAs, while fan oven generated the lowest level of total COPs. Thus, the developed method can form a basis for determination of COPs and HAs in duck as well as by choosing an appropriate roasting method their formation can be minimized.     

静磁场对人体自由基代谢的影响

观察强度为１５０～１５５ｍＴ的静磁场对健康志愿者血清超氧化物歧化酶（ＳＯＤ）、丙二醛（ＭＤＡ）和全血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）的影响，结果表明该强度的静磁场短期可以显著提高人体ＳＯＤ、ＧＳＨ－Ｐｘ的活性，降低ＭＤＡ的含量，提示该强度的静磁场具有提高自由基代谢的功能。     

肠毒素的生物电化学检测

论述了用电化学方法检测肠毒素的酶免疫电极，它兼有酶电极和免疫电极的特点，而酶电极的研究已较为成熟，免疫电极的电化学检测九十年代中期才刚刚兴起，正引起人们的广泛关注。实验中基底材料为玻碳电极，玻碳电极经过打磨抛光，超声清洗，再耦联生物分子。文中比较了用共价结合法，吸附法和电沉积法制备的生物传感器的响应特性，从实验结果可知镀有铂黑的生物电极，其表面积大大提高，酶、抗体等生物分子的结合量增多，因而检测能力也就随之增强。另一优点是信噪比提高，抗干扰能力加强。但缺点是重现性不好。电沉积法制备的电极重现性较好，但响应电流较小。制备具有高灵敏性和优良的稳定性的生物传感器是生物课题的研究方向     

130例多发性创伤的急诊救治分析

目的：探讨多发性创伤的临床特点及诊断与救治方法，提高救治成功率。方法：对130例多发性创伤患者的临床诊疗资料进行回顾性分析研究。结果：治愈115例；死亡7例,主要死亡原因：3例死于严重颅脑损伤合并脑疝,1例死于失血性休克,3例死于 MODS（多器官功能衰竭）。结论：多发性创伤患者的病情严重复杂，常为多脏器损伤，病情变化快、并发症多、易误诊漏诊、病死率高。尽早、快速正确实施救治处理，注意保护重要脏器功能，可以提高抢救的成功率。     

Occurrence and exposure to polycyclic aromatic hydrocarbons in kindling-free-charcoal grilled meat products in Taiwan

This study aimed to determine the contents of 16 PAHs in kindling-free-charcoal grilled meat and seafood products by GC–MS coupled with a QuEChERS method, and estimate the potential risk associated with consumption of those products in Taiwan. Results showed that the total PAHs contents ranged from 6.3 ± 0.9 to 238.8 ± 8.3 ng/g in poultry meat, 0.1 ± 0.0–547.5 ± 12.2 ng/g in red meat, and 6.6 ± 1.4–249.7 ± 6.4 ng/g in seafood products. Among various PAHs, the highly carcinogenic benzo[a]pyrene was detected in chicken breast grilled at 84 °C (30 min), chicken heart at 100 °C (26 min), chicken drumstick at 74 °C (20 min), duck drumstick at 85 °C (40 min), and lamb steak at 88 °C (12 min), with its level amounting to 1.3 ± 0.0, 2.4 ± 0.1, 4.0 ± 1.3, 3.1 ± 0.0, and 5.8 ± 0.5 ng/g, respectively. The generation of PAHs was associated with grilling time, temperature and fat content. Risk assessment of dietary exposure to PAHs revealed toxicity equivalent to range from ND – 6.174 ± 0.505 μg/g and margin of exposure was >10,000, which agreed with the EFSA’s definition of low public health concern. The lifelong average daily PAHs intake was higher for adults than for elderly people in Taiwan, however, consumption of kindling-free-charcoal grilled meat should not be a public health concern based on cancer risk potency.     

基于QuEChERS-GC-QQQ-MS/MS法同时测定知母中58种农药残留

目的建立基于QuEChERS-GC-QQQ-MS/MS的知母中58种农药残留同时定量分析方法。方法采用岛津TQ8050三重四极杆气质联用仪,Shimadzu SH-Rxi-5Sil MS毛细管柱(30 m×0.25 mm,0.25μm)为色谱柱;进样口温度为250℃,进样量为1.0μL,不分流进样,高压进样压力为250 k Pa;载气为高纯氦气,载气控制方式为恒线速度模式;色谱柱体积流量为1.69 mL/min,线速度为47.2 cm/s,吹扫流量为5 mL/min;程序升温:初始温度为50℃,保持1 min,先以25℃/min升温至125℃,再以10℃/min升温至300℃,保持15 min;柱平衡时间为0.5 min。采用QuEChERS法提取、净化供试品溶液;配制基质匹配标准曲线;使用稳定的同位素内标进行校正等3个措施共同消除基质效应。结果成功建立并验证了一种基于QuEChERS-GC-QQQ-MS/MS的知母中58种农药残留同时定量分析方法。通过对不同产地、野生与栽培品种、不同规格的知母药材进行58种农药残留量的定量测定,结果显示30个批次内共有6个批次知母药材检测到了微量的p,p′-滴滴伊(p,p′-DDE),3个批次检测到了氟乐灵,2个批次检测到了毒死蜱,1个批次检测到了微量的仲丁灵。结论建立的基于QuEChERS-GC-QQQ-MS/MS的知母中58种农药残留同时定量分析方法具有较好的适用性,对其他中药材农药多残留检测方法的建立具有参考价值。     

A Targeted UHPLC-MS/MS Method Validated for the Quantification of Ergot Alkaloids in Cereal-Based Baby Food from the Belgian Market

Following pending new legislation in the European Union setting a maximum of 20 ng g⁻¹ for the total sum of ergot alkaloids in dry cereal-based baby food, a new UHPLC-MS/MS method was developed. It is suitable for the quantification of six ergot alkaloids: Ergocornine, ergocristine, ergometrine, ergosine, ergotamine, α-ergocryptine, and their corresponding epimers. The method is able to reliably detect individual ergot alkaloids at a level as low as 0.5 ng g⁻¹. The method uses a modified QuEChERS extraction approach before UHPLC-MS/MS analysis. The method showed good sensitivity, accuracy, and precision. It has been applied to 49 samples from the Belgian market. In 26 samples, not a single ergot alkaloid was detected while in 23 out of 49 samples at least one ergot alkaloid was detected with 2 samples containing 12 ergot alkaloids. Ergometrine was the alkaloid most frequently detected i.e., 16 out of 49 samples. Only one sample, testing positive for all 12 ergot alkaloids, would be non-conforming to the newly proposed Maximum Residue Level (MRL).     

基于改进QuEChERS测定植物油中邻苯二甲酸酯类化合物的气相色谱串联质谱质谱方法研究

目的 针对现有方法的不足,改进QuEChERS程序,采用气相色谱串联质谱质谱仪（GC-MS/MS）建立植物油中16种邻苯二甲酸酯类化合物（PAEs）的检测方法。方法 对前处理条件和仪器条件进行优化后,样品经乙腈超声提取,加入PSA+Silica净化,振荡离心后取上清液进行测定,外标法定量。结果 各种PAEs出峰良好,方法线性范围为0.02mg/L~1.00mg/L,相关系数均大于0.998,方法检出限为0.00021mg/kg~0.014mg/kg,定量限为0.00068mg/kg~0.048mg/kg,3个加标浓度下的回收率为80.0%~103%,相对标准偏差（RSD%）为1.79%~6.96%,用本法检测了10个植物油样品,共有4种PAEs检出,分别是DBP、DEHP、DIBP和DNOP,本法和国标法检出值的相对偏差均小于10%。结论 该方法具有简便、高效、灵敏、快速等优点,能够很好地完成植物油中PAEs含量的检测。     

QuEChERS-UPLC-MS/MS法快速测定香茅草中33种农药残留量

目的:建立分散固相萃取(QuEChERS)快速样品前处理技术结合超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定香茅草中33种农药残留的方法。方法:以乙腈为溶剂,高速匀浆提取,经C18/PSA小柱及改良的QuEChERs填料净化。方法:采用Penomenex Kinetex XB-C18色谱柱(100 mm×2.1 mm,1.7μm),以0.1%甲酸(含5 mmol·L^-1乙酸铵)溶液和乙腈为流动相进行梯度洗脱,电喷雾电离源(ESI),正离子模式下多反应监测(MRM)。结果:14批样品中共检出农药5种,1个样品检出咪鲜胺(3.12 mg·kg^-1)、多菌灵(0.0518 mg·kg^-1)、吡虫啉(0.0351 mg·kg^-1)、烯酰吗啉(17.6 mg·kg^-1)和甲基硫菌灵(0.0471 mg·kg^-1);另外2个样品检出多菌灵(0.0157 mg·kg^-1和0.0129 mg·kg^-1),其余样品均未检出残留农药,合格率64.3%。33种待测指标成分线性关系良好,相关系数均大于0.995,两水平加样回收率全部指标在64.4%~114.7%,RSD为1.2%~9.6%,检测下限为1.0~5.0μg·kg^-1,符合多农残的痕量分析检测要求。结论:该方法有针对性地对香茅草中33种农药残留进行快速筛查与准确检测,适用于对中药香茅草的日常监控,同时为基质类似中药的农药残留方法提供借鉴。     

QuEChERS-气相色谱法测定水果中的五氯硝基苯

目的 建立水果中五氯硝基苯 (PCNB)的QuEChERS-毛细管气相色谱测定法。方法 样品采用QuECHERS进行预处理,选用正己烷提取,乙二胺-N-丙基硅烷(PSA)净化,以RTX-5毛细管色谱柱分离,电子捕获检测器检测,外标法定量。结果 本法在0.02-0.3 mg/kg范围内线性关系良好,相关系数为0.999 6,方法加标回收率为86.3%-105.4%,相对标准偏差小于4.15%,检出限为0.002mg/kg。结论 本法样品前处理简单快速、检出限低、重现性好,可用于水果中五氯硝基苯的测定。