The current study highlights the advantages of using the quality by design (QbD) approach to synthesise and optimize SERS substrates for the detection of Hg2+. Considering that the performance of Au@AgNPs is affected by many factors, Plackett-Burman (PB) experimental design was used to determine the critical process parameters (CPPs) for evaluating the performance of Au@AgNPs. The quantitative relationships between the CPPs and the critical quality attributes (CQAs) were assessed by Box-Behnken Design (BBD). The optimal design space for Au@AgNPs was calculated via a Monte Carlo algorithm. Finally, detection of Hg2+ in the range of 1 ∼ 100 ng mL-1 (R 2 = 0.9891) was achieved by SERS in combination with 4,4-bipyridine (Dpy) as signal molecules. The recoveries for licorice ranged from 83.53% to 92.96%. Specificity and practicality studies indicated that the method based on the QbD concept and design space not only met the optimal performance of Au@AgNPs but also improved the rapid detection of Hg2+ in Chinese medicine samples.

There has been an increasing demand for rapid and sensitive techniques for the detection of heavy metal ions that are harmful to the human body in traditional Chinese medicine (TCM). However, the complex chemical composition of TCM makes the quantitative detection of heavy metal ions difficult. In this study, the magnetic Fe3O4@SiO2@AuNPs nanoparticles combined with a probe molecule DMcT were used for the specific enrichment and detection of Hg2+ in the complex system of licorice. The core of Fe3O4 was bonded with SiO2 to increase its stability. A layer of AuNPs was deposited to produce a “core–shell” Raman substrate with high surface-enhanced Raman spectroscopy (SERS) activity, which was surface modified by DMcT probe molecules with sulfhydryl groups. In the presence of Hg2+, Hg2+ binds to N on the amino group of DMcT to form N-Hg2+-N complexes, which induces Fe3O4@SiO2@AuNPs-DMcT clustering to enhance SERS signal. The Raman probe molecule DMcT showed an excellent linear relationship (R2 = 0.9709) between the SERS signal at 1416 cm−1 and the Hg2+ concentration (0.5~100 ng/mL). This method achieved a good recovery (89.10~111.00%) for the practical application of detection of Hg2+ in licorice extracts. The results demonstrated that the functional Fe3O4@SiO2@AuNPs-DMcT performed effective enrichment and showed high sensitivity and accurate detection of heavy metal ions from the analytes.

为开发一种最优的糯山药贮藏方案,选取鲜切和预蒸煮两种不同方式预处理糯山药,杀菌真空包装后在25℃和-18℃下贮藏,对其感官品质、质构(硬度、弹性、咀嚼性和黏性)、褐变度及直链淀粉与支链淀粉的质量分数进行对比分析.结果显示:短期贮藏10 d时,糯山药在常温25℃和低温-18℃贮藏下,预蒸熟包装糯山药褐变高于鲜切包装糯山药,且黏性和支链淀粉质量分数显著下降.低温贮藏下,两种包装的糯山药的感官评分都高于常温贮藏的糯山药.长期贮藏100 d后,与新鲜糯山药相比,两种包装糯山药的硬度、咀嚼性和黏性均显著下降,但鲜切包装山药感官得分和支链淀粉质量分数均高于预蒸煮包装糯山药.因此,无论是短期贮藏10 d还是长期贮藏100 d,鲜切处理并在-18℃贮藏的糯山药综合品质最优.

BACKGROUND:Shenqi Jiangtang Granule (SJG), a classical prescription of traditional Chinese medicine, is widely used to treat diabetes and its complications. Although, the clinical efficacy of SJG, is sufficient, the pharmacokinetic behavior of various substances in the plasma of SJG is unknown. OBJECTIVE:The aim of this study was to investigate the plasma pharmacokinetics during absorption of SJG after oral administration in rats. METHODS:A rapid and accurate ultra-high performance liquid chromatography/tandem mass spectrometry (UPLC- MS/MS) method was developed for the simultaneous determination of eight analytes in SJG, including gomisin D, schisandrin A, schisandrin B, schizandrol A, schizandrol B, ginsenoside Rd, ginsenoside Re and notoginsenoside Ft1. The analysis was carried out on a BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with gradient elution at a flow rate of 0.2 mL/min in a mobile phase consisting of 0.1% formic acid water and acetonitrile. In addition, lignans and saponins were detected in positive ion mode and negative ion mode, respectively. RESULTS:Eight analytes in SJG, including gomisin D, schisandrin A, schisandrin B, schizandrol A, schizandrol B, ginsenoside Rd, ginsenoside Re and notoginsenoside Ft1, showed good linearity (R2 in the range of 0.9955 ~ 0.9999). The lower limit of quantification (LLOQ) was 5, 0.8, 0.8, 8, 0.8, 5, 0.6 and 10 ng/mL. The accuracy and precision of all analytes were at ±15%. Matrix effect and average extraction recovery were > 85%. All analytes performed well under four storage conditions. CONCLUSION:The results showed that in vivo absorption and exposure of gomisin D and ginsenoside Rd were better than other analytes, while schizandrol B and notoginsenoside Ft1 were poorly absorbed. This approach could be applied to study the pharmacokinetic characteristics of various analytes in plasma after oral administration of SJG in rats.