Cost‐efficient magnetic nanoporous carbon derived from citrus peel for the selective adsorption of seven insecticides

A magnetic solid‐phase extraction adsorbent that consisted of citrus peel‐derived nanoporous carbon and silica‐coated Fe₃O₄ microspheres (C/SiO₂@Fe₃O₄) was successfully fabricated by co‐precipitation. As a modifier for magnetic microspheres, citrus peel‐derived nanoporous carbon was not only economical and renewable for its raw material, but exerted enormous nanosized pore structure, which could directly influence the type of adsorbed analytes. The C/SiO₂@Fe₃O₄ also possessed the advantages of Fe₃O₄ microspheres like superparamagnetism, which could be easily separated magnetically after adsorption. Integrating the superior of biomass‐derived nanoporous carbon and Fe₃O₄ microspheres, the as‐prepared C/SiO₂@Fe₃O₄ showed high extraction efficiency for target analytes. The obtained material was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and the Brunauer–Emmett–Teller method, which demonstrated that C/SiO₂@Fe₃O₄ was successfully synthesized. Under the optimal conditions, the adsorbent was selected for the selective adsorption of seven insecticides before gas chromatography with mass spectrometry detection, and good linearity was obtained in the concentration range of 2–200 μg/kg with the correlation coefficient ranging from 0.9952 to 0.9997. The limits of detection were in the range of 0.03–0.39 μg/kg. The proposed method has been successfully applied to the enrichment and detection of seven insecticides in real vegetable samples.     

Remediation of azo-dyes based toxicity by agro-waste cotton boll peels mediated palladium nanoparticles

The present study reports an environmental benign route for the synthesis of palladium nanoparticles (Pd NPs) using agro-waste empty cotton boll peels aqueous extract for the first time. Surface Plasmon Resonance (SPR) band in absorption spectrum of Pd NPs at 275 nm confirmed the formation of Pd NPs by using UV–Vis spectroscopy. Crystalline nature of Pd NPs was confirmed by powder XRD analysis. Size and morphology was studied by transmission electron microscopy (TEM). The cotton peels extract acted as a source of phytochemicals which primarily reduced Pd⁺² to Pd⁰ nanoparticles (Pd NPs) and imparted stability of Pd NPs by surface capping. The characteristic functional groups of phytochemicals in extract and capped Pd NPs surfaces were identified by FT-IR analysis. Catalytic activity of the synthesised Pd NPs was checked against reduction of hazardous azo-dyes such as Congo red, Methyl orange, Sunset yellow and Tartrazine with NaBH₄ as electron donors. Pd NPs catalysed reduction of all azo-dyes by NaBH₄ in aqueous medium was monitored by UV–visible spectroscopy where Pd NPs mediated transfer of electrons from NaBH₄ to azo-dyes as carrier. The synthesized Pd NPs acted as a good catalyst and could be a promising material in degrading toxic azo-dyes from industrial effluents and wastewater.     

高效液相色谱法测定柑橘皮中柠檬苦素

提出了高效液相色谱法测定柑橘皮中柠檬苦素含量的方法。样品用体积分数为70%乙醇溶液于50℃超声提取75min。以Sinochrom ODS-BP(250mm×4.6mm,10μm)为分离柱,以乙腈-水(45+55)溶液作为流动相,用紫外检测器在波长210nm处进行测定。柠檬苦素的质量浓度在12.0～384mg.L-1范围内与其峰面积呈线性关系,方法的平均回收率为99.9%,相对标准偏差(n=5)为1.8%。     

柚子皮衍生类蜂窝状碳材料在同步检测重金属离子中的应用

不含金属的碳材料通过廉价且易获得的柚子皮经KOH活化和高温热解获得,该碳材料具有高比表面积(1 055 m~2·g~(-1))和高石墨化程度的类蜂窝状结构。将多孔碳(PAC)材料修饰后的电极作为工作电极,采用阳极溶出伏安法(SWASV)同步检测Cd~(2+)、Pb~(2+)和Cu~(2+)离子,表现出较高的灵敏度、可重复性、稳定性和较低的检测限。研究认为PAC的微孔和中孔可以充当有效的离子传递通道,从而加速离子的扩散并显著提高交换效率,而高的石墨化程度提高了材料的导电性,加速了电子传输。     

不同产地茯苓皮药材红外光谱的识别

采用红外光谱、二阶导数光谱和二维相关红外光谱对大别山地区和云南省两大道地主产区的茯苓皮进行鉴别分析。结果表明,不同产地茯苓皮的红外光谱都有1 149,1 079和1 036cm-1等表征糖类成分的特征吸收峰,其中大别山产区(湖北省、安徽省)的茯苓皮中1 619,1 315和780cm-1等表征草酸钙的特征吸收峰比较显著,云南产区的茯苓皮中797,779,537和470cm-1等表征硅酸盐的特征吸收峰更加明显。比较450~1 650cm-1波数范围内的二阶导数红外光谱可知,两个产区茯苓皮所含糖类物质有所不同。在二维相关红外光谱中,不同产地茯苓皮所含糖类物质的差异更加直观显著。红外光谱法直观、简单、方便、快速,可以作为鉴别不同产地茯苓皮,诠释产地与药效之间关联性的一种有效准确的新方法。     

大孔吸附树脂分离纯化山核桃蒲壳总生物碱

用经筛选的大孔树脂分离纯化山核桃蒲壳总生物碱.选择极性不同的D101、AB-8、NKA-9 3种大孔树脂,比较其对山核桃蒲壳中总生物碱的吸附率和解吸率的影响,筛选较优树脂,并以总生物碱的纯化倍数和固体得率为考察指标,探索纯化工艺.NKA-9大孔树脂对山核桃蒲壳总生物碱有较好的吸附和解吸效果;pH为7.0的山核桃蒲壳生物碱提取液经大孔树脂吸附后,依次用蒸馏水2BV、30%乙醇2BV、50%乙醇3BV洗脱,总生物碱富集在50%乙醇部分,纯化倍数达到3.173倍,固体物得率为34.78%.采用NKA-9大孔树脂可以较好地分离纯化山核桃蒲壳总生物碱.     

高效液相色谱法测定柑橘皮中新橙皮苷

提出了高效液相色谱法测定柑橘皮中新橙皮苷含量的方法。样品用甲醇超声提取,定容至50mL。以SinoChrom ODS-BP色谱柱(250mm×4.6mm,10μm)为分离柱,以甲醇-水(36+64)溶液作为流动相,用紫外检测器在波长283nm处进行测定。新橙皮苷质量浓度在0.005 3～0.32g.L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)为0.6mg.L-1。方法的平均回收率为90.3%,相对标准偏差(n=6)为1.7%。     

色谱-质谱联用技术在我国3种柚子组分鉴定及指纹图谱建立中的应用

利用色谱-质谱联用技术对我国主要的3个品种柚子果实的不同部位(外表皮、内表皮、内果皮、果肉、种子)的化学组分进行结构鉴定及种类和含量的差异性分析,结果表明,沙田柚、琯溪蜜柚、玉环柚果实5个部位共鉴定出68种不同化学组分物质,包括醇类19种、酯类15种、烯烃类9种、有机酸类8种、酮类7种、烷烃类4种、其他物质6种。其中3个品种柚子外表皮共有的化学组分有7种,含量最高的是柠檬烯(44.03%);内表皮共有的化学组分有6种,含量最高的是油酸酰胺(44.62%);内果皮共有的化学组分有10种,含量最高的是谷甾醇(30.75%);果肉共有的化学组分有11种,含量最高的是软脂酸(20.02%);种子中共有的化学组分有15种,含量最高的是亚油酸(45.83%)。化学组分差异性分析结果表明,沙田柚、琯溪蜜柚、玉环柚3种柚子的外表皮独有的化学组分分别有3种、6种、4种,内表皮分别有3种、4种、8种,内果皮分别有1种、4种、6种,果肉分别有4种、4种、2种,沙田柚、玉环柚种子独有的化学组分均为1种,并对化学组分进行聚类分析和相似度分析。研究结果说明不同品种柚子同一部位的化学组分种类和含量均存在相似性和差异性,特有物质较多,色谱指纹图谱特异性显著,这可为柚类品种鉴定、品质质量控制、原产地溯源等提出一种新的色谱指纹图谱思路。     

柚子皮生物炭质用于河水中苯系物的固相微萃取

苯、甲苯、乙苯和二甲苯(邻二甲苯、间二甲苯、对二甲苯)组成的苯系物(BTEX)是炼油厂和石化厂等工业园区普遍制造和排放的碳氢化合物,具有一定的毒性和致癌作用,对生态环境和人类健康造成极大威胁。研究以低成本、绿色且富含木质素和含氧官能团的柚子皮作为植物原料,在有限氧条件下采用程序升温热解法制备了柚子皮生物炭质吸附剂,通过N₂吸附-脱附等温线和孔径分布图对不同热解温度下制备的柚子皮生物炭质吸附剂的孔隙结构进行了考察。结果表明:在1000 ℃热解温度下制得的柚子皮生物炭质具有更高的比表面积(749.9 m²/g)、更大的孔体积(0.42 cm³/g)、更集中的孔径分布(2~3 nm)。将吸附剂通过溶胶-凝胶法(sol-gel)涂覆在铁丝上制成固相微萃取纤维,与气相色谱-火焰离子化检测器(GC-FID)相结合,对影响萃取和分离BTEX的条件进行优化,建立了用于BTEX检测的高灵敏度分析方法。方法具有检出限低(0.004~0.032 μg/L)、线性范围宽(1~100 μg/L)、线性关系好、萃取效率高(约为商品化涂层聚二甲基硅氧烷(7 μm)的2.9~18.3倍)等优势。此外,应用该方法已成功在河水样本中检测出了乙基苯(4.80 μg/L),邻二甲苯(3.00 μg/L)和对二甲苯、间二甲苯(2.46 μg/L)。最后将该方法应用于河水样本的加标试验中,得到了满意的回收率(75.7%~117.6%)。实验结果表明所建立的分析方法可实现对环境水样(河水)中BTEX的低成本、高灵敏度检测。