液质联用法测定蔬菜、水果、土壤中的溴氰虫酰胺残留

建立了一种超高效液相色谱-电喷雾电离串联质谱法测定蔬菜、水果和土壤中的溴氰虫酰胺残留的方法。试样经QuEChERS方法前处理,超高效液相色谱-电喷雾电离串联质谱法测定,外标法定量。溴氰虫酰胺在0.5-200μg/L有良好的线性关系,相关系数r0.999,检出限为0.15μg/kg,定量下限为0.5μg/kg,加标回收率在70%-110%,相对标准偏差小于5.0%,该方法简便、可靠、稳定,灵敏度高,可用于分析蔬菜、水果和土壤中溴氰虫酰胺的残留量。     

HPLC-ICP-MS法测定水样中的甲基汞、乙基汞和无机汞

建立了高效液相色谱(HPLC)和电感耦合等离子体质谱(ICP-MS)联用测定环境水样中的甲基汞、乙基汞和无机汞的方法。实验使用的高效液相色谱流动相为含有0.06mol/L乙酸氨,20μg/LBi,0.1%(V/V)2-巯基乙醇的5%(V/V)甲醇-水溶液,色谱柱为C18反相柱(5μm,2.1mm×50mm),经前处理的水样在液相色谱中分离后,进入电感耦合等离子体质谱检测其甲基汞、乙基汞和无机汞的浓度。甲基汞、乙基汞和无机汞检出限分别为0.05μg/L、0.10μg/L和0.10μg/L。     

加速溶剂萃取-高效液相色谱法同时测定大气颗粒物PM2.5中16种多环芳烃

建立大气颗粒物PM2.5中16种优控多环芳烃(PAHs)的加速溶剂萃取-高效液相色谱法同时测定方法。用中流量PM2.5采样器,以玻璃纤维滤纸为滤料,以100 L/min的流速连续采样24 h。采样后的玻璃纤维滤纸经正己烷-丙酮(6∶4,ν/ν)于加速溶剂萃取仪中提取,提取液浓缩后用乙腈定容,通过C18色谱柱分离,紫外和荧光检测器检测。16种PAHs在0.20~5.00μg/m L范围内线性相关系数r≥0.999 8,检出限为0.002~0.012μg/m L,方法平均回收率为71.3%~96.5%,相对标准差为0.50%~4.8%。该法简便、快速、准确、灵敏,将其应用于成都市3个区域空气颗粒物PM2.5中16种PAHs的测定,结果理想。     

高效液相色谱法测定不同产地地骨皮中东莨菪内酯的含量

建立高效液相色谱测定地骨皮中东莨菪内酯含量的方法。方法采用ZORBAX C18色谱柱,以40%甲醇水溶液(含0.2%磷酸)为流动相,检测波长为345nm。东莨菪内酯在15~0.12μg/m L的范围内呈良好的线性关系(r=0.9996),检测限为0.067μg/m L。该方法操作简单、灵敏度高、精密度良好,可准确测定地骨皮中东莨菪内酯的含量。利用建立的方法测定了国内不同产地地骨皮中东莨菪内酯的含量。     

植物油中苯并(a)芘液相色谱检测方法的研究

本文研究了植物油中苯并(a)芘的高效液相色谱检测法。试样中的苯并(a)芘用丙酮提取,液相色谱-荧光检测器测定,外标峰面积法定量。苯并(a)芘在(0.5~20)ng/m L范围内呈良好的线性关系,3个水平(2.5μg/kg、5.0μg/kg、10.0μg/kg)添加苯并(a)芘的回收率为93.0%~104.4%,相对标准偏差(RSD)为2.9%~3.9%,检出限为1.0μg/kg。此方法简便、快捷,适用于植物油中苯并(a)芘的检测。     

教科书中荧光增白剂VBL的分析方法研究

利用高效液相色谱-荧光检测器法对教科书中VBL荧光增白剂进行了测定。具体方法为用岛津LC-20AD高效液相色谱系统,Eclipse-C18柱(250 mm×4.6mm,5.0μm)色谱柱,流动相A为甲醇,B为8mmol/L乙酸铵水溶液,流速0.5mL/min,激发波长350nm,发射波长430nm,进样量1μL。外标法测定教科书中VBL荧光增白剂的含量,检测线性关系R~2=0.9985,回收率为92.5%～94.5%之间,相对标准偏差为0.81%(n=6)。研究结果表明,高效液相色谱-荧光检测器法操作简便,结果准确,不受木质素和其他荧光物质的干扰,具有较好的重现性与稳定性,可用于教科书中VBL荧光增白剂含量的测定。     

液相色谱-质谱法测定动物源性食品中的三聚氰酸及其同系物

采用UPLC BEH Amide(2.1 mm×100 mm×1.7μm)色谱柱,以10%乙酸铵水溶液和乙腈为流动相进行梯度洗脱,流速为0.4 mL/min,进样量5μL,柱温为40℃。建立同时检测动物源性食品中三聚氰酸、三聚氰酸一酰胺、三聚氰酸二酰胺含量的高效液相色谱-质谱联用方法。三聚氰酸、三聚氰酸一酰胺、三聚氰酸二酰胺在0.05～250 mg/L浓度范围内线性关系良好(r~2≥0.99),加标回收率均在88.0%～102.8%之间。该方法简便、快速、灵敏度高,适用于测定动物源性食品中三聚氰酸、三聚氰酸一酰胺、三聚氰酸二酰胺的含量。     

高效液相色谱-三重四级杆质谱法测定豆制品中二甲基黄、二乙基黄

建立一种同时测定豆制品中二甲基黄、二乙基黄的高效液相色谱-三重四级杆质谱(HPLC-MS/MS)方法。对提取溶剂及色谱条件进行优化,粉碎后的样品经乙腈提取,提取液以HPLC-MS/MS测定,外标法定量。二甲基黄、二乙基黄在3 min内流出并完全分离,两者在0.05~10μg/L范围内相关系数r2均大于0.999,二甲基黄在0.5~50μg/kg的加标回收率为90.0%~93.4%,RSD为0.5%~5.1%,二乙基黄在0.5~50μg/kg水平的加标回收率在84.6%~93.8%,RSD为1.1%~4.6%,检出限两者均为0.2μg/kg。该方法操作简捷、准确度和精密度高,适用于豆制品中二甲基黄、二乙基黄的检测。     

RP-HPLC法同时测定12种植物油中的3种甾醇含量

采用反相高效液相色谱法(RP-HPLC)建立同时测定植物油中菜油甾醇、豆甾醇和β-谷甾醇含量的方法。采用C8柱(250 mm×4.6 mm×5μm)为色谱柱,流动相A相为乙腈,B相为水,通过梯度洗脱方式,以流量为1 m L/min,紫外检测波长210 nm对植物油中菜油甾醇、豆甾醇和β-谷甾醇进行分离检测。结果表明,菜油甾醇、豆甾醇和β-谷甾醇的质量浓度范围分别为5.12~101.4,5.08~101.6,5.09~101.8μg/m L时,3个甾醇的线性关系良好(线性方程分别为y=3 699x-5 454,y=4 951x+8 889,y=3 994x-3 800;相关系数r2分别为0.998 9,0.999 9,0.999 4),检测限为2.5μg/m L,平均回收率分别为99.79%~100.6%,98.17%~99.80%以及97.76%~102.24%,进样精密度(n=6)分别为2.29%,1.66%,2.12%,重复性RSD分别为2.49%,1.78%,2.72%,稳定性RSD分别为1.95%,2.56%,2.40%。通过对12种植物油中3种甾醇含量进行同时测定,表明相对于气相色谱法(GC),采用HPLC法具有更稳定、更准确、更简便等特点,是同时检测植物油中菜油甾醇、豆甾醇和β-谷甾醇的较好方法。     

液相色谱-串联质谱法同时测定饲料中矮壮素和缩节胺的残留

本文采用高效液相色谱-串联质谱(HPLC-MS/MS)同时测定饲料中的矮壮素和缩节胺残留。样品先用正己烷脱除油脂,后用缓冲溶液(含0.2%甲酸-0.05mol/L乙酸铵)提取,离心上清液用乙腈沉淀净化后进行测试。结果表明:两种化合物在1.0~50.0μg/L范围内线性关系良好;定量限(S/N=10)矮壮素为0.32μg/L,缩节胺为0.45μg/L;加标回收率为91.7%~94.3%;相对标准偏差3.9%~6.1%;实测有30%的样品中含有矮壮素或缩节胺,含量范围为:矮壮素11.2μg/kg-78.4μg/kg;缩节胺9.7μg/kg-126.6μg/kg。该方法简便、快速、灵敏和准确,适合饲料中这两种农药残留的快速检测和定量分析。     

高效液相色谱法测定3种邻苯类增塑剂检测条件的研究

选择邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)3种标准物质为研究对象,建立了高效液相色谱法检测邻苯二甲酸酯的条件,对实验方法的准确程度进行了分析。结果表明,以甲醇-水为流动相,采用梯度模式洗脱,检测波长为225nm,柱温为30℃,流量为1.000mL/min,进样量为10μL时,可以很好地分离3种邻苯二甲酸酯,目标分析物质量浓度在0.5～100μg/mL范围之间时,得到的线性相关系数在0.999 96～0.999 98之间;重复性实验表明,10次实验的保留时间的相对标准偏差在0.0314%～0.0389%之间,峰面积的相对标准偏差在0.0942%～0.353%之间,DMP,DEP,DBP的方法检测限分别为0.0228,0.0277,0.0489μg/mL。     

Characterization of doxycycline-loaded calcium phosphate cement: implications for treatment of aneurysmal bone cysts

Percutaneous doxycycline for treatment for aneurysmal bone cysts (ABCs) has been shown to decrease recurrence rates, however, this requires multiple procedures, includes the risks soft tissue necrosis, and does not provide structural support. We propose utilizing curettage with doxycycline-loaded calcium phosphate cement. This study aimed to evaluate the elution profile of doxycycline from calcium phosphate cement. Calcium phosphate cement underwent an in vitro elution protocol evaluating doxycycline concentrations of 0, 5, 10, and 15?mg/mL. Eluted concentrations were quantified utilizing high performance liquid chromatography at predetermined time points over 96?h. Compressive strength was evaluated both pre- and post-elution and micro-computed tomography was utilized to assess changes in cement porosity. Cement with 15?mg/mL of doxycycline maintained a higher average concentration (mean, 95% confidence intervals) (14.5?µg/mL [9.2–19.9?µg/mL]) compared to both 5?mg/mL (5.8?µg/mL [3.1–8.6?µg/mL]; P?<?0.001) and 10?mg/mL (8.4?±?µg/mL [6.0–10.9?µg/mL]; P?<?0.001). Ultimate stress significantly decreased between pre- and post-elution samples for 10?mg/mL (P=?0.001) and 15?mg/mL (P?=?0.004) groups. This study demonstrated a dose-dependent response in ultimate strength and compressive modulus with addition of doxycycline to calcium phosphate cement.     

双酚S迁移量的快速检测及迁移规律研究

目的研究聚醚砜中双酚S迁移量的快速检测方法,以及双酚S的迁移规律。方法以液相色谱-质谱法(LC-MS)快速测定模拟液乙醇(体积分数为50%)、乙酸(质量浓度为30 g/L)及水中双酚S的迁移量,并以此为基础,研究不同的介质、温度、时间、厚度等因素对双酚S迁移规律的影响。结果该法对双酚S的检出限为2.0μg/L,定量限为6.0μg/L,在模拟液水、乙醇(体积分数为50%)、乙酸(质量浓度为30 g/L)中的加标回收率分别为95.2%~102%,97.3%~102%,96.3%~102%,相对标准偏差分别为2.6%~4.2%,2.6%~4.0%,3.3%~4.7%;在相同条件下,双酚S在乙醇(体积分数为50%)中的迁移量最大,其迁移量顺序为乙醇(50%)乙酸(30 g/L)水,同时符合温度越高则迁移量越大、厚度越大迁移量越高的规律。结论采用液相色谱-质谱法检测双酚S,具有操作简便、灵敏度高、重复性好、结果准确等特点;食品模拟物的属性是影响双酚S迁移行为的重要因素,同时,温度和厚度也影响着双酚S在PES中的迁移。     

Effect of diclofenac on ocular levels of ciprofloxacin and lomefloxacin in rabbits with endophthalmitis

The purpose of this study was to analyze ciprofloxacin and lomefloxacin penetration into the anterior eye tissues after topical instillation in healthy rabbits and with experimental Staphylococcus aureus endophthalmitis. Additionally, effect of diclofenac sodium eye drops on the distribution of both fluoroquinolones in the inflamed eye tissues was investigated. An intense protocol with frequent antibiotic administration was chosen. Samples from aqueous humor were obtained 2 and 6?h after the start of the treatment. Samples from cornea and iris were obtained at the end of the experiment, after euthanasia of the animals. Drug concentrations were measured by HPLC method. The median levels of ciprofloxacin and lomefloxacin in aqueous humor of healthy animals, 2 and 6?h after drug administration were 6.39–9.65 and 5.30–6.81?µg/ml, respectively. Ciprofloxacin levels were neither changed from the inflammation nor after instillation of diclofenac. In contrary, lomefloxacin concentrations in aqueous humour of inflamed eye were significantly increased 12.15–15.08?µg/ml, especially after diclofenac administration (17.12–27.76?µg/ml). Levels of both fluoroquinolones in cornea (13.08?µg/g for ciprofloxacin and 12.25?µg/g for lomefloxacin) and in iris (0.84?µg/g for ciprofloxacin and 1.34?µg/g for lomefloxacin) were higher than MIC and MBC values against S. aureus ATCC 25923. Although higher lomefloxacin concentrations were observed in the aqueous humor after instillation of diclofenac, the levels of both fluoroquinolones in iris and in cornea were not significantly changed. Topical administration of lomefloxacin and diclofenac in combination improved penetration of the antibacterial agent in the aqueous humor which can be of clinical importance.     

Galbanic acid,a sesquiterpene coumarin as a novel candidate for the biosynthesis of silver nanoparticles: In vitro hemocompatibility,antiproliferative, antibacterial,antioxidant, and anti-inflammatory properties

In the current study, silver nanoparticles (AgNPs) were biosynthesized using galbanic acid (GA), a sesquiterpene coumarin. The formation of GA-AgNPs was characterized by ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), Energy Dispersive X-ray (EDX), and X-ray diffraction (XRD). The biosynthesized GA-AgNPs were spherical in shape with an average particle size of 142.33 ± 32.6 nm. The results from the antibacterial assays suggested that biosynthesized GA-AgNPs were more potent against multi-drug resistant (MDR) and non-MDR pathogenic bacteria than the crude GA alone. The nanoparticles also showed potent antiproliferative potential against H1229 and MCF-7 cancer cells with IC50 values of 25 μg/mL and 50 μg/mL by the MTT assay, respectively. These NPs showed good antioxidant (30 % at 100 µg/mL), anti-inflammatory (99.5 % at 500 µg/mL), and anti-coagulant properties without significant hemolysis on red blood cells (RBCs). These results confirm the benefits of using the green, simple, and cost-effective manner for the synthesis of AgNPs with excellent biological properties and hemocompatibility.     

Graphene-Au nanoparticle based electrochemical immunosensor for fish pathogen Aphanomyces invadans detection

Epizootic ulcerative syndrome (EUS) that is primarily caused by an invasive oomycete fungus Aphanomyces invadans is a devastating fish disease. Rapid diagnosis of EUS is significantly important for the control and treatment of this highly invasive disease. In our study, a label-free immunosensor constructed with G-AuNPs/SAM-Ab-BSA/GCE was proposed for the determination of Aphanomyces invadans. The electrode was prepared by the immobilization of anti-mycelium antibodies on graphene-AuNPs nanocomposite-cysteamine monolayers modified GCE. The optimized parameters were as follows: 90 min as the immersion time of SAM modified electrode in the anti-mycelium solution, 0.20 µg/mL as the concentration of anti-mycelium solution and 10 min as the interaction time of immunoreaction. The immunosensors exhibited low limit detection of 309 ng/mL and good reproducibility.     

PVA-coated miniaturized flexible fiber optic sensor for acetone detection: a prospective study for non-invasive diabetes diagnosis

Diabetes is a complex metabolic disorder that leads to various health complications. Present conventional diagnostic methods of puncturing a finger cause pain, discomfort and measurement procedures often lead to irregular testing. Therefore, there is a need for a simple, painless, and portable technique, which can diagnose diabetes non-invasively and in real-time. Acetone vapor in human exhaled breath is a natural biomarker correlated with some metabolic diseases, like diabetes. Thus in this work, Fabry–Perot Interferometer-based polyvinyl alcohol-coated sensor platform for acetone vapor detection non-invasively at room temperature has been proposed and investigated for the prospective study of diabetic detection. The developed sensor platform of approx. 61 μm cavity length was employed for acetone sensing from 0 to 80 µL/L concentration. The evaluation parameters of the developed sensor like sensitivity, the limit of detection, response and recovery time for the acetone vapor detection at room temperature were observed in the order of 43.9 pm/(µL/L), 0.45 µL/L, 60 s and 10 s, respectively. The cross-sensitivity of the sensor was checked with methanol and ethanol. The experimentally observed sensitivity response (swelling) was found in agreement with the theoretically calculated miscibility values obtained from the Hansen solubility parameter model. The thermal stability of the developed sensor was also studied and found linear between the temperature ranges of 25–75 °C. The proposed sensor is simple, miniaturized, flexible, cost-effective, and highly sensitive for low acetone vapor concentration detection at room temperature. Therefore, this sensor maybe explore for diagnosis of diabetes non-invasively via acetone detection from the exhaled breath.

     

粮食中T-2/HT-2毒素胶体金快速定量法研究

以小麦、玉米为原料,采用胶体金快速定量法检测其T-2/H-2毒素含量并探讨胶体金快速定量法的适用性,同时,采用高效液相色谱-串联质谱联用法(LC-MS/MS)验证该方法的准确性。结果表明,小麦、玉米中T-2/H-2毒素胶体金快速定量法检出限分别为4.3μg/kg和2.9μg/kg,定量限分别为10.9μg/kg和8.0μg/kg,重复性符合检测要求,方法回收率介于80%~116%,具有良好的特异性。因此,胶体金快速定量法作为快速检测粮食中T-2/H-2毒素的技术具有较高的准确性和稳定性。     

茶叶中镁含量分析方法研究

本文研究了刚果红分光光度法测定茶叶中镁含量的方法。结果表明：在一定条件下,镁离子含量在0～45μg／25mL范围内遵守朗伯比尔定律,检测限为3．8p,g／L,方法的表观摩尔吸光度为1．27×10^4L·mol^-1·cm^-1,方法的精密度（RSD）小于2．5％,样品加标回收率在96％-103％之间,结果令人满意。     

Apparent Solubility of Drugs in Partially Crystalline Systems

Abstract

Using several griseofulvin samples, representing different solid-state structures, the solubility behavior of drugs in both one-state (totally ordered, semiordered or disordered) and two-state systems was studied. Special attention was directed towards the surface structure of the particles. The partially crystalline samples were obtained by milling the raw material (crystalline standard) or storing the quenched sample (amorphous standard). The solid-state structure of the materials was studied using x-ray diffraction (XRD), differential scanning calorimetry (DSC), isothermal microcalorimetry (IMC), and scanning electron microscopy (SEM). The saturation concentration of the materials was studied in suspensions containing different dispersion concentrations of drug after centrifugation and filtration, using spectrophotometry. In all cases these dispersion concentrations exceeded the solubility of the drug. The solubilities were plotted vs. dispersion concentrations for each sample. Several solubility plateaus were found. The lowest and highest solubility plateaus corresponded to the solubilities of crystalline and amorphous standards. These plateaus were reached at 8 and 44 µg/mL for crystalline and amorphous griseofulvin standards, respectively. An intermediate plateau served as an indication of the existence of a totally semiordered structure. This was reached at 19 µg/mL for griseofulvin. Any deviation from these plateaus was suggested to be indicative of the existence of heterogeneity on the surface structure, which in most cases could be described as a two state system. In such cases, the apparent solubility was a function of dispersion concentration, until at very high dispersion concentrations (4000–20,000 µg/mL) the saturation concentration of the totally disordered (44 µg/mL) or semiordered (19 µg/mL) one-state phase was reached. No reduction in these values was observed during storage for 50 days. It is thus concluded that, in partially crystalline systems, the saturation concentration is an interfacial phenomenon, which depends on the amount, reactivity, and solid-state structure of the exposed solid surfaces in equilibrium with the solution. A simplified solubility model is proposed to qualitatively describe the relationship between established apparent solubilities (saturation concentrations) and different combinations of solid-state structures.