超高效液相色谱-串联质谱法快速测定葱、姜、蒜与辣椒酱中的66种有机磷农药残留

建立了青葱、生姜、大蒜和辣椒酱中66种有机磷农药多残留的快速分析方法.样品用陶瓷均质子配合乙腈涡旋提取,盐析除水,提取液经Carb,C18和PSA粉末分散固相萃取净化后,采用超高效液相色谱-串联质谱(UPLC-MS/MS )进行分析,经HSS T3色谱柱分离,在电喷雾离子化正离子方式(ESI+)及多反应监测模式(MRM...     

溶剂转移-气相色谱-质谱法和选择洗脱-气相色谱法测定大蒜中289种农药多残留

以溶剂转移净化为核心步骤,建立了一种适用于大蒜样品中农药多残留分析的前处理方法(方法I),配以一个辅助方法(方法II),构成大蒜中常见289种农药多残留的分析体系(方法I283种,方法II6种)。方法I中,样品用乙腈-水溶液提取,盐析分配,溶剂转移和固相萃取(SPE)净化后进行气相色谱-质谱(GC-MS)分析;方法II中,样品用无水Na2SO4配合乙酸乙酯均质研磨,超声波辅助提取,提取液经Primary Secondary Amine (PSA)粉末分散固相萃取和LC-Si柱选择洗脱净化后进行GC分析。GC-MS采用选择离子监测(SIM)方式,GC采用火焰光度检测器(FPD)检测,外标法定量。方法简便、快速,通过优化前处理和上机条件,在最优条件下进行测试,方法的定量限(S/N≥10)为0.01～0.05 mg/kg。方法I中,在加标水平为0.02、0.20 mg/kg时,回收率为52%～163%,其中回收率在70%～120%之间的占88%,相对标准偏差为2.4%～18%;方法II中,在加标水平为0.01、0.02、0.10、0.20 mg/kg时,回收率为70%～111%,相对标准偏差为3.2%～9.3%。详细描述了实验模型的构建,并对GC-MS灵敏度的提高提出了新的见解。该方法准确、灵敏、快速,可满足大蒜中多种农药残留的检测要求。     

植酸对镉蒜的解毒行为研究

本实验用植酸以直接加入和预浸泡两种方式3种方法处理镉蒜,通过测量处理前后的蒜根平均长度,测定根、茎、叶中的镉含量及不同部位镉的不同存在形式的含量,分析比较出采用植酸对镉蒜的最佳解毒方式.本实验还从细胞学上探讨了镉对蒜植株的毒害效果及机理.结果发现,解毒效果佳的蒜根较其它组长,培养液中镉含量较高,植株体内镉含量较少且运输到茎叶的镉量较大,与植酸结合的镉的氯化钠结合态含量高.经实验得出预浸泡过的蒜植株抵御镉毒害的效果最佳,而混合培养与先中毒再解毒的效果相近,混合培养较后解毒的效果略好.     

冷柱头程序升温进样-气相色谱/质谱法研究新鲜大蒜中的有机硫化合物

采用冷溶剂提取新鲜大蒜中的有机硫化合物,结合冷柱头程序升温进样,对大蒜原始组分进行了气相色谱/质谱分析 。该法实现了从提取到色谱分离的“冷过程”,因而可以准确地鉴定大蒜提取液在热分解前的原始组分。分析结果表明, 在大蒜提取液中含有3-乙烯基-1,2-二硫杂-5-环己烯及其异构体2-乙烯基-1,3-二硫杂-4-环己烯两种主要组分以及少量 的S-甲基甲烷硫代亚磺酸酯、二烯丙基二硫醚、二烯丙基三硫醚。对大蒜的冷溶剂提取液和水蒸气蒸馏提取的大蒜油中 的有机硫化合物进行了比较,对一些主要有机硫化合物的形成进行了初步探讨。     

气相色谱-质谱法测定大蒜挥发油的组成

采用改进的水蒸汽蒸馏法从山东金乡大蒜中提取挥发油。实验确定了气相色谱-质谱法分析大蒜油的条件,并对大蒜挥发油的化学成分进行了定性分析,共鉴定出20种物质。用峰面积归一化法对各物质的相对含量进行了测定,结果表明含硫化合物约占挥发油总成分的95%以上,其中含量最高的是大蒜新素,约占挥发油总量的三分之一。对低温储藏半年的挥发油进行分析的结果表明样品在低温下可稳定存放。     

Demonstration of Allium sativum Extract Inhibitory Effect on Biodeteriogenic Microbial Strain Growth,Biofilm Development,and Enzymatic and Organic Acid Production

To the best of our knowledge, this is the first study demonstrating the efficiency of Allium sativum hydro-alcoholic extract (ASE) againstFigure growth, biofilm development, and soluble factor production of more than 200 biodeteriogenic microbial strains isolated from cultural heritage objects and buildings. The plant extract composition and antioxidant activities were determined spectrophotometrically and by HPLC–MS. The bioevaluation consisted of the qualitative (adapted diffusion method) and the quantitative evaluation of the inhibitory effect on planktonic growth (microdilution method), biofilm formation (violet crystal microtiter method), and production of microbial enzymes and organic acids. The garlic extract efficiency was correlated with microbial strain taxonomy and isolation source (the fungal strains isolated from paintings and paper and bacteria from wood, paper, and textiles were the most susceptible). The garlic extract contained thiosulfinate (307.66 ± 0.043 µM/g), flavonoids (64.33 ± 7.69 µg QE/g), and polyphenols (0.95 ± 0.011 mg GAE/g) as major compounds and demonstrated the highest efficiency against the Aspergillus versicolor (MIC 3.12–6.25 mg/mL), A. ochraceus (MIC: 3.12 mg/mL), Penicillium expansum (MIC 6.25–12.5 mg/mL), and A. niger (MIC 3.12–50 mg/mL) strains. The extract inhibited the adherence capacity (IIBG% 95.08–44.62%) and the production of cellulase, organic acids, and esterase. This eco-friendly solution shows promising potential for the conservation and safeguarding of tangible cultural heritage, successfully combating the biodeteriogenic microorganisms without undesirable side effects for the natural ecosystems.     

液相色谱-质谱联用银离子诱导电离分析大蒜粉剂中二烯丙基硫化物

烯丙基硫化物由于弱极性不电离,本实验利用Ag 柱后诱导电离对大蒜粉剂中的含硫化合物进行质谱定性,并以二烯丙基三硫醚为参比,对各种二烯丙基含硫化合物进行定量测定。采用甲醇-水梯度洗脱,色谱柱为W aters Symm etry C18(3.9 mm×150 mm,5μm)柱,流动相流速为0.5 mL/m in,30 m in实现良好分离。将1 mmol/L AgNO3衍生试剂以5μL/m in流速注入柱后管路,毛细管电压3 kV,正离子电离方式质谱检测。结果表明,含硫化合物的色谱行为符合“硫数规律”(lgk′=0.4276 0.0364n,r=0.9910);利用该类化合物摩尔吸光系数与二烯丙基三硫醚相近的原理,进行大蒜粉剂中含硫化合物定量分析,比硫酸钡重量法和银量定硫法更合理。     

Superfast Synthesis of Stabilized Silver Nanoparticles Using Aqueous Allium sativum (Garlic) Extract and Isoniazid Hydrazide Conjugates: Molecular Docking and In-Vitro Characterizations

Green synthesis of silver nanoparticles (AgNPs) was synthesized from fresh garlic extract coupled with isoniazid hydrazide (INH), a commonly used antibiotic to treat tuberculosis. A molecular docking study conducted with the selected compounds compared with anthranilate phosphoribosyltransferase (trpD) from Mycobacterium tuberculosis. The aqueous extract of garlic was prepared and mixed with silver nitrate (AgNO3) solution for the superfast synthesis of stable AgNPs. INH was then conjugated with AgNPs at different ratios (v/v) to obtain stable INH-AgNPs conjugates (AgNCs). The resulting AgNCs characterized by FTIR spectra revealed the ultrafast formation of AgNPs (<5 s) and perfectly conjugated with INH. The shifting of λmax to longer wavelength, as found from UV spectral analysis, confirmed the formation of AgNCs, among which ideal formulations (F7, F10, and F13) have been pre-selected. The zeta particle size (PS) and the zeta potential (ZP) of AgNPs were found to be 145.3 ± 2.1 nm and −33.1 mV, respectively. These data were significantly different compared to that of AgNCs (160 ± 2.7 nm and −14.4 mV for F7; 208.9 ± 2.9 nm and −19.8 mV for F10; and 281.3 ± 3.6 nm and −19.5 mV for F13), most probably due to INH conjugation. The results of XRD, SEM and EDX confirmed the formation of AgNCs. From UV spectral analysis, EE of INH as 51.6 ± 5.21, 53.6 ± 6.88, and 70.01 ± 7.11 %, for F7, F10, and F13, respectively. The stability of the three formulations was confirmed in various physiological conditions. Drug was released in a sustainable fashion. Besides, from the preferred 23 compounds, five compounds namely Sativoside R2, Degalactotigonin, Proto-desgalactotigonin, Eruboside B and Sativoside R1 showed a better docking score than trpD, and therefore may help in promoting anti-tubercular activity.     

提取大蒜有效成分--有机硫化物

文中研究了用乙醚萃取法提取大蒜中的有机硫化物,采用了正交实验方法考查了操作条件对提取物得率的影响,确定了影响产物得率的主要因素为酶解温度、酶解pH值、酶解时间、加水量以及离心pH值。确定了最佳提取条件为:酶解温度25℃,酶解pH值7.0,酶解时间60min,加水量100mL,离心pH值32。实验还发现二次萃取可以减少产物的流失.     

薄层扫描法测定挥发大蒜油中的大蒜辣素

挥发大蒜油在薄层板上分离出的最大斑点的化学成分用红外光谱法定性,用薄层扫描法定量。大蒜辣素在0．667-1．112μg范围内峰面积和质量的线性关系良好(r=0．9988),方法的平均回收率为98．4％,RSD=0．59％(n=5)。实验结果表明这种方法简便、快捷、准确。