ABSTRACT
The contamination of aflatoxin B_1,B_2,G_1,G_2,M_1 and M_2 in Eupolyphaga Steleophaga was determined by immunoaffinity column clean-up and HPLC-FLD with post-column photochemical derivatization. Chromatographic separations were carried out using a Cloversil C_(18) column( 4. 6 mm×250 mm,5 μm) that were eluted in isocratic with methanol-acetonitrile-water( 20 ∶ 20 ∶ 60) as the mobile phase. The excitation wavelength and the emission wavelength of fluorescence detector were maintained at 360 nm and 450 nm,respectively. The flow rate was 0. 8 m L·min~(-1),and the column temperature was 30 ℃ ． The sample was prepared using the immunoaffinity column,then the recovery was measured with 75. 47%-101. 8% with RSD values lower than 6. 7%. A total of 20 batches of Eupolyphaga Steleophaga samples were assayed. According to the Chinese Pharmacopoeia( 2015 edition,part 1),the aflatoxin B_1 limit should be less than 5 μg·kg~(-1),and the sum of aflatoxins( AFB_1,AFB2,AFG_1,AFG_2) should be less than 10 μg·kg-1. Therefore,the positive rate of the 20 samples was 50. 0%,and 7 batches of samples exceeded the standard,and the over-standard rate was as high as 70. 0%. Among them,aflatoxins B_1,B_2,G_1,G_2,M_1,and M_2 were detected in three batches( SD-1,AH-1,AH-3),and aflatoxins B_1,B2,G1,G2,and M1 were detected in one batch( AH-7). The results showed that the newly developed method in this work is suitable for the simultaneous determination of six aflatoxins in Eupolyphaga Steleophaga,and also suggested that it should be of high values to take the contamination with aflatoxins into concerns.
Subject(s)
Animals , Aflatoxins/analysis , Chromatography, Affinity , Chromatography, High Pressure Liquid , Cockroaches/chemistryABSTRACT
Objective To compare the advantages and disadvantages between high performance liquid chromatography (HPLC)-ultraviolet (UV, HPLC-UV), HPLC-fluorescence detector (FLD, HPLC-FLD) and HPLC-mass spectrometry (MS, HPLC-MS) for determination of the monoamine neurotransmitters (MNs) in brain tissues of mice, and to determine the content of MNs in brain tissues of vascular depression mice using the optimal method. Methods We used the UV, FLD and MS detectors to establish different methods for determination of dopamine (DA), norepinephrine (NE) and 5-hydroxytryptamine (5-HT) in brain tissues. Then the methods was verified with methodology. The HPLC-FLD was applied for the content determination of DA, NE and 5-HT in different brain tissues of vascular depression mice. Results It was observed that the limits of quantification for HPLC-UV, HPLC-FLD and HPLC-MS were DA 103.5 ng/mL, NE 107.5 ng/mL and 5-HT 93.6 ng/mL; 10.35 ng/mL, 10.75 ng/mL and 9.36 ng/mL; and 10.35 ng/mL, 32.25 ng/mL and 9.36 ng/mL, respectively. Both HPLC-FLD and HPLC-MS for DA and 5-HT were superior to HPLC-UV. HPLC-FLD for NE was superior to HPLC-MS. Compared with HPLC-UV and HPLC-FLD, HPLC-MS showed remarkable matrix effects. HPLC-FLD determination results showed that content of DA was the lowest in hippocampus, 5-HT was the lowest in cerebral cortex, and NE did not differ in different brain tissues of vascular depression mice. Conclusion Compared with HPLC-UV and HPLC-MS, HPLC-FLD can more effectively determine the contents of MNs (DA, NE and 5-HT). DA and 5-HT can be used as the diagnostic markers of the vascular depression diseases.
ABSTRACT
BACKGROUND: Propofol (2,6-diisopropylphenol) is one of the intravenous anesthetic drugs used for induction and maintenance of general anesthesia as well as for sedation in ICU patients and one-day surgery. The monitoring of propofol in blood helps to maintain anesthetic state and promote earlier recovery. So we attempted to find the rapid and simple method for blood propofol determination. METHODS: We compared the precipitation method with extraction one using whole blood, plasma and deionized water added a fixed amount of propofol. According to the extraction method, propofol was extracted from 500 microliter sample adding KH2PO4, ethyl acetate, and tetra-ethylammonium hydroxide using thymol as an internal standard. For the precipitation method, the precipitating solution (500 microliter) containing thymol was added to a 500 microliter sample, then mixed. After centrifugation, the supernatant was injected into HPLC system. A Waters 2690 separations module, Waters 474 fluorescence and 486 UV detector and a Symmetry column were used. We used Millennium software to control analyzing process and quantify propofol. RESULTS: The precipitation method using thymol as an internal standard and Waters 474 fluorescence detector showed the most excellent results. For the calibration curves, we found very good linearity in whole blood, plasma and deionized water (r> or =9976). Intra-assay and inter-assay coefficient of variation (CV) values of propofol for the precipitation method were 4.4% and 8.9% at 2 microgram/mL of propofol and 2.0% and 6.2% at 8 microgram/mL, respectively. The recovery rates of propofol for plasma and whole blood were 104.1% and 92.7% at 2 microgram/mL and 99.4% and 91.6% at 7 microgram/mL, respectively. CONCLUSIONS: For the measurement of the blood propofol level, the precipitation method using thymol as an internal standard and fluorescence detector seemed to be the rapid and simple method to apply for the clinical purpose.