1.A novel luminol-based chemiluminescence method for the determination of amikacin sulfate in serum by using trivalent copper-periodate complex
Yufei HU ; Gongke LI ; Zhujun ZHANG
Journal of Pharmaceutical Analysis 2013;(5):360-366
A novel chemiluminescence (CL) reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex (K5[Cu(HIO6)2], DPC) in alkaline medium. The CL intensity could be enhanced in the presence of amikacin sulfate (AKS). A new CL method was developed for the determination of AKS by coupling with flow injection (FI) technology. Because of the distinctive oxidative effect of DPC, the luminol-based CL reaction could occur at a low concentration of 10à7 M. The relative CL intensity was proportional to the concentration of AKS in the range of 4.0 ? 10à9-4.0 ? 10à6 g/mL with the detection limit of 1.2 ? 10à9 g/mL. The relative standard deviation was 2.1% for 8.0 ? 10à9 g/mL AKS (n?9). The proposed method was successfully applied to the direct determination of AKS at the level of ng/mL in serum samples. The recovery varied from 97.0% to 106.3%. A possible mechanism of the CL reaction was discussed in detail by relating to the CL kinetic characteristics and electrochemical activities of the oxidant DPC.
2.A Flow Injection Chemiluminescence Method for Determination of Hydrocortisone in Human Serum by Trivalent Silver Complex
Zhaofu FU ; Gongke LI ; Yufei HU
Chinese Journal of Analytical Chemistry 2015;(9):1322-1328
A flow-injection chemiluminescence ( FI-CL ) reaction system with diperiodatoargentateⅢ was developed for the determination of hydrocortisone in human serum. The weak chemiluminescence signal from the reaction between DPA and sulfuric acid system can be greatly enhanced in the presence of hydrocortisone. The optimal conditions of the CL system were 1. 0 mol/L H2SO4, 2. 5×10-4 mol/L diperiodatoargentateⅢ, and flow rate of 4. 20 mL/min. Under the optimal conditions, the CL intensity was linearly to the concentration of hydrocortisone from 3 . 0 × 10-10 g/mL to 1 . 0 × 10-7 g/mL and the detection limit was 2 . 2 × 10-10 g/mL ( 3σ) . The relative standard deviation ( RSD ) was 0 . 6% ( n =11 ) for 5 . 0 × 10-8 g/mL hydrocortisone solution. The proposed method was successfully applied to the direct determination of hydrocortisone in serum samples with the recoveries of 93 . 0%-110 . 0%, and the relative standard deviations were 0 . 3%-3 . 2%. The possible chemiluminescence mechanism was investigated by measuring fluorescence spectra and UV-vis absorption spectra of the system.
3.A chemiluminescence reagent free method for the determination of captopril in medicine and urine samples by using trivalent silver
Zhaofu FU ; Wanting HUANG ; Gongke LI ; Yufei HU
Journal of Pharmaceutical Analysis 2017;7(4):252-257
A novel flow-injection chemiluminescence (FI-CL) method free of CL reagent was developed for the determination of captopril based on its enhancing effect on the CL derived from diperiodatoargentate(III)-sulfuric acid system. Compared with the conventional CL system, the CL system based on trivalent silver was characterized of good selectivity for the absence of CL reagent. The CL mechanism was discussed through CL spectra and UV–vis absorption spectra. The conditions of the FI-CL system were investigated and optimized. Under the optimal conditions, the relative CL intensity was linear with the captopril concentration in the range of 0.3–15.0 μg/mL. The detection limit for captopril was 0.05 μg/mL, and the relative standard deviation (n=11) was 2.0% for 5.0 μg/mL captopril. The proposed method was applied to the analysis of captopril in tablet and human urine with the recoveries of 83.1%–112.5%, and the relative standard deviations of 0.5%–4.4%. The results obtained by the proposed method agreed well with those obtained from HPLC method. The proposed method is fast, convenient, and cost-effective for the determination of captopril in medicine and biological samples.
4.Study on chromatographic fingerprint of sarcandra glabra (Thunb.) by microwave-assisted extraction coupled to HPLC/DAD
Zhuomin ZHANG ; Zongning GUO ; Guihua RUAN ; Jianchao DENG ; Xiaohua XIAO ; Gongke LI
Journal of Pharmaceutical Analysis 2010;22(4):211-217
Microwave-assisted extraction (MAE) was used for extraction of effective components of sarcandra glabra (Thunb.), and then chromatographic fingerprint of sarcandra glabra (Thunb.) was studied by high performance liquid chromatography/diode array detector (HPLC/DAD). The conditions of MAE were optimized by an orthogonal experiment, and then the authentication and validation of the chromatographic fingerprint were conducted. Nine peaks were identified as common peaks in the fingerprint chromatograms, and isofraxidin was considered as a reference compound and quantified. Relative standard deviations of retention time and peak area of each component were less than 3% and 8%, respectively. Similarity and difference analysis were conducted by use of PCA and relation coefficient. Twenty batches of sarcandra glabra (Thunb.) samples from two different producing areas could be classified into two different groups in the PCA model. The results showed that MAE-HPLC/DAD method was simple, efficient and stable for the study of complex chromatographic fingerprint of sarcandra glabra (Thunb.), which could provide more reliable and precise information for quality evaluation.
5.Advances of supercritical fluid chromatography in lipid profiling
Yang YANG ; Yanshan LIANG ; Jina YANG ; Fengying YE ; Ting ZHOU ; Gongke LI
Journal of Pharmaceutical Analysis 2019;9(1):1-8
Supercritical fluid chromatography (SFC) meets with great favor due to its high efficiency, low organic solvent consumption, and the specialty for the identification of the isomeric species. This review de-scribes the advances of SFC in targeted and untargeted lipid profiling. The advancement of the SFC in-struments and the stationary phases are summarized. Typical applications of SFC to the targeted and untargeted lipid profiling are discussed in detail. Moreover, the perspectives of SFC in the lipid profiling are also proposed. As a useful and promising tool for investigating lipids in vitro and in vivo, SFC will predictably obtain further development.
6.Preparation of Trimethoprim Molecularly Imprinted Stir Bar Sorptive Extraction and Its Application for Trace Analysis of Trimethoprim and Sulfonamides in Complex Samples
Zhigang XU ; Zhuo DU ; Yuling HU ; Yufei HU ; Yingpeng PAN ; Gongke LI
Chinese Journal of Analytical Chemistry 2012;40(7):1002-1010
Trimethoprim molecularly imprinted polymer (MIP) was prepared as the coating of stir bar sorptive extraction (SBSE) and applied to the trace analysis of trimethoprim and three sulfonamides in complex samples.The MIP-coating was about 21.5 μm thickness with the relative standard deviations (RSD) of 5.9% (n=10).It was homogeneous and dense with good thermal and chemical stability.The extraction capability of the MIP-coating was 1.7 times over that of the non imprinted polymer (NIP) coating.The MIP coating exhibited selective adsorption ability to sulfonamides,triazines and methotrexate besides antibacterial synergists.The methods for the determination of trimethoprim and three sulfonamides by MIP-coated stir bar sorptive extraction coupled with HPLC were developed.It was successfully applied to the trace trimethoprim analysis in spiked urine and plasma samples.The linear range was 5 to 200 μg/L and the detection limit was 1.6 μg/L.The recoveries in urine and plasma samples were 84.5% to 91.7% with RSDs of 2.9% -4.4%,71.9% to 85.1% with RSDs of 3.0% -7.3%,respectively.The trimethoprim MIP-coated stir bar was also applied to the trace sulfonamides analysis in spiked milk sample.The linear range was 10-200 μg/L,the detection limit was within the range of 4.5-6.1 μg/L,and the recovery was 83.2% - 110.2% with RSDs of 4.1% -8.0%.
7.Analysis of timing and prognostic factors of early tracheotomy in patients with multiple rib fractures
Bing ZHANG ; Gongke LI ; Yurong WANG ; Fei WU ; Suqin SHI ; Qinling FENG ; Xin HANG ; Runfeng MIAO ; Le XIA ; Cheng DUAN ; Juling LENG ; Yong LI
Chinese Journal of Trauma 2021;37(7):646-652
Objective:To investigate the related factors that affect the timing and prognosis of early tracheostomy in patients with multiple rib fractures.Methods:A retrospective case series study was conducted on medical data of 222 patients with multiple rib fractures who underwent tracheostomy in Affiliated Hospital of Yangzhou University from February 2013 to October 2019,including 160 males and 66 females,with the age of 18 to 85 years [(49.5 ± 16.3)years]. According to the practice management guidelines for tracheostomy timing and the use of propensity score matching technology,there were 118 patients with tracheostomy within 7 days of tracheal intubation (early group) and 104 patients with tracheostomy after 7 days of tracheal intubation (late group) before matching,and there were 87 patients in early group and 87 patients in late group after matching. Data were compared between groups including the gender,age,underlying disease,injury severity score (ISS),Glasgow coma score (GCS),number of fractured ribs,total number of rib fractures (NTRF),first rib fracture,flail chest,traumatic brain injury,combined injuries (spine,maxillofacial,sternum),acute respiratory distress syndrome (ARDS),volume fraction of pulmonary contusion(VPC),blood lactic acid (within 24 hours of admission),hemothorax,pneumothorax,mechanical ventilation time,duration of tracheostomy,time from tracheal intubation to incision,length of hospital stay,length of stay in ICU,closed thoracic drainage,number of fiberoptic bronchoscopy,multi-drug resistant bacteria infection,ventilator-associated pneumonia,antibiotic use time,duration of sedative and analgesic drugs used and 28-day mortality. The multivariate Logistic regression analysis was used to predict independent risk factors for early tracheostomy. The Pearson method was used to compare the relationship between multiple factors. The receiver operating characteristic (ROC) curve was used to predict indicators that affect the prognosis of patients with early tracheostomy,and calculate the best cut-off value. The Kaplan-Meier single factor and COX multivariate survival were used to analyze the relevant factors affecting the 28-day mortality of patients.Results:(1) In early group,the NTRF,ARDS and VPC were higher than those in late group,and the time from tracheal intubation to incision and 28-day mortality rate were lower than those in late group ( P < 0.05),while the two groups showed no significant differences in the gender,age,underlying diseases and ISS ( P > 0.05). (2) The multivariate Logistic regression analysis showed that there was statistical significance in NTRF ( OR = 1.775,95% CI 1.439-2.188),ARDS( OR = 3.740,95% CI 1.441-9.711),VPC ( OR = 1.087,95% CI 1.052-1.124) ( P < 0.05); the Pearson method analysis showed a significant correlation between VPC and NTRF ( r = 0.369, P < 0.05) and a low degree of correlation between ARDS and VPC ( r = 0.179, P < 0.05),but there was no significant correlation between ARDS and NTRF ( r = 0.132, P > 0.05). (3) The ROC curve analysis showed that the area under the curve (AUC) of the VPC and NTRF [AUC = 0.832 (95% CI 0.770-0.893),AUC = 0.804 (95% CI 0.740-0.868)] were significantly higher than those of the number of rib fractures [AUC = 0.437(95% CI 0.352-0.523),GCS [AUC = 0.519 (95% CI 0.432-0.605)] and ISS [AUC = 0.484 (95% CI 0.398-0.571)] ( P < 0.05). After calculating the Yorden index,the best cut-off value for VPC was 23.9,and the best cut-off value for NTRF was 8.5. (4) The Kaplan-Meier single factor and multivariate COX model survival analysis showed that the 28-day survival ratio of patients with early tracheostomy was significantly better than that of late tracheostomy ( P < 0.05). Conclusions:The NTRF,ADRS and VPC are independent risk factors for the timing and prognosis of early tracheostomy. There is a significant correlation between VPC and NTRF. The VPC ≥ 23.9% and or NTRF ≥ 8.5 can be used to predict early tracheostomy in patients with multiple rib fractures. Early tracheostomy may benefit the 28-day survival of patients with multiple rib fractures.