反相离子对HPLC法测定盐酸二甲双胍中双氰胺的含量

目的建立反相离子对HPLC法测定盐酸二甲双胍中双氰胺含量的方法。方法采用Agilent HC-C18(2)色谱柱(250 mm×4.6 mm,5μm),以甲醇-10 mmol/L庚烷磺酸钠溶液(含0.8%三乙胺,用H3PO4调pH 3.0)(15∶85)为流动相;流速:1.0 mL/min;检测波长:218 nm;柱温:30℃。结果反相离子对HPLC法测定盐酸二甲双胍中双氰胺含量的线性范围为0.01~26.12μg/mL;相关系数r=0.999 9;重复性的RSD为1.8%;精密度RSD为1.6%;高、中、低3种浓度的加样回收率分别为98.8%,102.1%,103.6%;RSD分别为0.8%,1.2%,0.9%。结论此法简便、快速、准确、专属性好。     

HPLC法测定盐酸二甲双胍肠溶微丸胶囊中双氰胺的含量

目的:建立HPLC法测定盐酸二甲双胍肠溶微丸胶囊中的有关物质(双氰胺)的含量方法。方法:色谱条件为:Inertsil-ODS-3(4.6mm×150mm,5μm),流动相为乙腈-0.05%庚烷磺酸钠水溶液(16∶84),检测波长218nm,流速1mL·min~(-1)。结果:进样量在0.5～5ng时,与峰面积线性关系良好,r=0.9998(n=6)。平均回收率99.4%,精密度RSD=0.5%(n=6)。     

Trace residue analysis of dicyandiamide,cyromazine, and melamine in animal tissue foods by ultra-performance liquid chromatography

An effective sample preparation procedure using an accelerated solvent extraction (ASE) procedure, followed by cleaning with melamine molecularly imprinted polymers solid-phase extraction (MISPE) was developed. A novel and highly sensitive ASE–MISPE–ultraperformance liquid chromatography (UPLC) method was developed for effective separation and simultaneous determination of dicyandiamide (DCD), cyromazine (CYR), and melamine (MEL) in complex animal tissue foods. Under optimized conditions, good linearity was achieved with a correlation coefficient (r) of 0.9999 in the range of at least two orders of magnitude. The limit of quantification of the method was 1.7 μg/kg, 5.0 μg/kg, and 3.2 μg/kg for DCD, MEL, and CYR, which was three orders of magnitude smaller than the maximum residue limits (MRLs). The intra- and inter-day precisions (in terms of the relative standard deviation, RSD) of the three analytes were in the range of 1.7–3.1% and 3.1–6.3%, respectively. The average recoveries of analytes from blank chicken, beef, mutton, pork, and pig liver samples spiked with the three levels varied from 91.2% to 107% with RSD of 1.7–8.3% for DCD, 89.0–104% with RSD of 2.1–6.1% for CYR, and 94.8–105% with RSD of 1.1–6.6% for MEL. The proposed method has the characteristics of speed, sensitivity, and accuracy, and can be used for the routine determination of DCD, CYR, and MEL at the μg/kg level in complex animal tissue foods.     

HPLC-MS/MS测定盐酸苯乙双胍及片剂中双氰胺的含量

 目的 建立高效液相色谱-质谱/质谱（HPLC-MS/MS）测定盐酸苯乙双胍及片剂中有关物质双氰胺含量的方法。方法 色谱条件：采用Agilent Eclipse XDB-C₁₈色谱柱(4.6 mm×150 mm,3.5 μm),以甲醇-0.1%甲酸溶液(30∶70) 为流动相;流速：0.5 mL·min-1;柱温：30 ℃;质谱条件：采用大气压化学电离(APCI )源进行正离子检测,选择离子监测(SRM) 方式定量分析,双氰胺和内标盐酸苯丙醇胺的监测离子对分别为m/z85→68和m/z152→134。结果 HPLC-MS/MS测定盐酸苯乙双胍中双氰胺含量的线性范围为0.001～10.41 μg·mL-1 (r=0.999 9);加样回收率平均值达98.0%,RSD为1.8%;中间精密度的RSD为5.3%;重复性的RSD为1.9%。结论 本法灵敏度高、专属性强、简便、快速、准确,适用于盐酸苯乙双胍及片剂中双氰胺的定量测定。     

Nitrogen-Doped Hierarchical Porous Activated Carbon Derived from Paddy for High-Performance Supercapacitors

A facile and environmentally friendly fabrication is proposed to prepare nitrogen-doped hierarchical porous activated carbon via normal-pressure popping, one-pot activation and nitrogen-doping process. The method adopts paddy as carbon precursor, KHCO₃ and dicyandiamide as the safe activating agent and nitrogen dopant. The as-prepared activated carbon presents a large specific surface area of 3025 m²·g⁻¹ resulting from the synergistic effect of KHCO₃ and dicyandiamide. As an electrode material, it shows a maximum specific capacitance of 417 F·g⁻¹ at a current density of 1 A·g⁻¹ and very good rate performance. Furthermore, the assembled symmetric supercapacitor presents a large specific capacitance of 314.6 F·g⁻¹ and a high energy density of 15.7 Wh·Kg⁻¹ at 1 A·g⁻¹, maintaining 14.4 Wh·Kg⁻¹ even at 20 A·g⁻¹ with the energy density retention of 91.7%. This research demonstrates that nitrogen-doped hierarchical porous activated carbon derived from paddy has a significant potential for developing a high-performance renewable supercapacitor and provides a new route for economical and large-scale production in supercapacitor application.     

HPLC法测定盐酸二甲双胍片的含量和有关物质

目的建立HPLC法测定盐酸二甲双胍片的含量和有关物质的方法。方法采用依利特Hypersil BDS CN（4．6mm×250mm）色谱柱,甲醇-水（10：90）（含0．003％三乙胺,用0．1mol·L^-1盐酸调节pH=5．4）为流动相,含量测定检测波长232nm,有关物质检测波长215nm。结果盐酸二甲双胍在0．01-0．1mg·L^-1范围内线性关系良好（r=0．99998）;平均回收率为99．9％,RSD为0．84％（n=9）。结论本方法快速、简便、准确,可用于盐酸二甲双胍片的质量控制。