液相色谱-串联质谱法测定进出口人参、西洋参中蚜灭磷等6种农药

建立了人参、西洋参中凝胶色谱-固相萃取-液相色谱-串联质谱法测定蚜灭磷、吡虫啉、涕灭威、甲基内吸磷、甲硫威、辛硫磷6种农药的分析方法。样品经丙酮超声提取,凝胶色谱(GPC)净化后,固相萃取(SPE)净化,在HPLC/MS/MS多反应监测(MRM)模式下进行了定性和定量分析方法。在上述检测方法条件下,所测的6种农药的最低检出限为0.01 mg/kg,回收率范围为79.2%~107.3%,线性范围为0.01~0.2 mg/kg。     

Temperature-related changes in the structure of YSAG:Yb garnet solid solutions with high Sc3+ concentration

The paper presents the results of the Sc³⁺ solubility limits estimation in dodecahedral and octahedral garnet sites for 1100–1700 °C temperature range. The region of existence of solid solutions with the garnet structure in the Y₂O₃-Al₂O₃-Sc₂O₃ and Yb₂O₃-Al₂O₃-Sc₂O₃ systems narrows with increasing synthesis temperature. The Sc³⁺ solubility in the dodecahedral site of the YbSAG and YSAG garnets decreases with increasing temperature, and at 1700 °C it is about 64 at. %. In the octahedral site of YbSAG garnet, the Sc³⁺solubility decreases from 89.5 to 66.5 at. % with increasing temperature, and in the YSAG system it is about 97.5 at.%. The overall Sc³⁺ solubility with the simultaneous introduction into both garnet sites is lower than with doping on one of the sites and also decreases with increasing temperature. The thermal stability of the compositions belonging to single-phase regions was confirmed by vacuum sintering up to 1850 °C.     

检测报告的价值

阐述了实验室检测报告的基本概念、标准作业流程及检测报告中常出现的问题,并从授权签字人的角度提出了如何审核检测报告,以保证检测报告的准确性和有效性;探讨了在新时代背景下,检测报告赋予新型的科学技术服务机构的新理念。     

QuEChERS-HPLC-MS/MS法快速筛查与确证人参花中14种农药残留

建立了QuEChERS-高效液相色谱-三重四极杆质谱法测定人参花中14种农药残留的分析方法。样品使用1%醋酸乙腈进行初步提取,再用乙二胺-N-丙基硅烷(PSA)、C18和石墨化炭黑(GCB)这3种吸附剂进行净化,采用多反应监测模式(MRM)进行检测,基质外标法定量。结果表明,14种农药的浓度和样品峰面积在0.5~100μg/L范围内呈良好线性关系(R²>0.999),在3个添加水平下测得回收率在70.8%~108.7%之间,测定结果的相对标准偏差在2.06%~10.35%范围内(n=6)。该方法灵敏度高、净化效果好,可同时快速检测人参花中多种农药残留,具有良好的定性和定量检测性能。     

ICP-OES/ICP-MS法测定赤瓟中微量元素

建立赤瓟中微量元素的测定方法。样品经HNO₃-H₂O₂体系微波消解,ICP-OES/ICP-MS法测定赤瓟中的Al、Ti、V、Mn、Fe、Ni、Cu、Zn、Sr、Mo、Ba、Ca、Na、Mg、P等15种微量元素,其中ICP-MS法以钪、铟为内标物进行校正,消除基体的干扰,同时通过两种仪器对婴幼儿米粉内部质控样品中的5种元素测定进行方法学考察,方法线性关系良好,标准物质结果均在满意范围内。该方法简便,快速,测定结果准确度高,重复性好,可用于赤瓟中微量元素的测定。     

鹿皮胶多糖对酒精性肝损伤的保护作用

目的:探究鹿皮胶多糖对急性酒精性肝损伤的保护作用。方法:采用浸提法提取鹿皮胶粗多糖,使用柱色谱分离纯化得到鹿皮胶纯多糖,应用柱色谱、红外光谱及理化学反应实验对其理化性质进行鉴定。通过测定小鼠血清中谷草转氨酶(AST)、谷丙转氨酶 (ALT)、谷胱甘肽过氧化酶(GSH-Px)、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量及肝匀浆上清液中GSH-Px、SOD活性和MDA含量,观察小鼠肝组织切片,以探究其对急性酒精性肝损伤的保护作用。结果:鹿皮胶多糖属于吡喃糖结构的酸性多糖,其形态为白色絮状,分子量为41.2 kDa,含量达86.71%,无淀粉、酚类、蛋白质、氨基酸及还原糖残基。动物实验结果显示,与模型组比较,鹿皮胶多糖中、高剂量组可显著提高小鼠血清中SOD、GSH-Px活性(P<0.05),降低ALT、AST活性和MDA含量(P<0.05);同时可显著提高肝组织匀浆上清液中SOD、GSH-Px活性(P<0.05),显著降低MDA含量(P<0.05)。结论:鹿皮胶多糖对急性酒精性肝损伤小鼠表现出明显的保护作用。     

基于高分辨质谱技术的植物源性药食同源特色农产品中10种农药残留的测定和快速筛查

建立了人参、五味子、刺五加、人参花、灵芝和灵芝孢子粉基质中10种农药残留的高分辨液相质谱检测及筛查方法,样品中残留的农药采用乙腈提取,经氯化钠及乙酸钠盐析分层,提取液经无水硫酸镁、N-丙基乙二胺(PSA)和石墨化炭黑(GCB)吸附剂分散固相萃取净化,用高效液相色谱-高分辨质谱定性.在上述检测方法条件下,所测的10种农药...     

液相色谱串联质谱法测定鸡蛋粉中16种磺胺类药物的残留量

目的建立液相色谱串联质谱法同时定性定量测定鸡蛋粉中16种磺胺类药物残留量的分析方法。方法样品中的16种磺胺类物质用0.2%甲酸乙腈提取后,由Oasis Prime HLB固相萃取柱净化,经SB C18色谱柱(2.1 mm×150 mm, 3.5μm)分离,以0.1%甲酸溶液和乙腈为流动相进行梯度洗脱,流速为0.25 mL/min,柱温为30℃。多反应监测模式测定,外标法定量。结果 16种目标化合物线性良好,相关系数均大于0.9992,方法的最低检出限在0.1～0.5μg/L之间,大部分待测物的平均回收率为79.9%～95.8%,相对标准偏差为3.1%～12.0%。结论该方法快速、准确,适用于鸡蛋粉中16种磺胺类药物残留量的检测。     

Antibacterial mechanism of adzuki bean seed coat polyphenols and their potential application in preservation of fresh raw beef

The monomeric phenolic components of adzuki bean seed coat polyphenols (ABSCPs) were analysed, and their antibacterial activity and mechanism against two tested bacteria (Escherichia coli ATCC8797 and Staphylococcus aureus ATCC12600) were evaluated for their potential application in preservation of fresh raw beef. ABSCP contained 13 kinds of monomeric phenols, and the minimum inhibition concentration (MIC) of ABSCP against E. coli and S. aureus was 1250 and 625 μg ml⁻¹, respectively. The mechanism of ABSCP against E. coli and S. aureus was associated with increased cell protein and nucleic acid leakage, increased cell membrane potential, decreased intracellular ATP concentration and morphological changes in bacterial cell. In addition, ABSCP with whey protein isolate (WPI) was applied to fresh raw beef and this remarkably retarded microbial growth by maintaining the total microbial quality below the acceptable limit of 6 lg CFU g⁻¹ for 14 days. Lower pH and total volatile base nitrogen values were observed in the coated samples during refrigerated storage (4 °C). As a result, we found that ABSCP, as a natural food bacteriostatic agent, can effectively inhibit the growth of E. coli and S. aureus and combined with WPI to apply to fresh raw beef to extend its shelf life.