Publications by authors named "Xiaoqing Fei"

Quaternary ammonium salt bactericides are broad-spectrum bactericides often used in oral care products because of their high antibacterial efficacy, strong penetration, and low toxicity. However, the excessive use of quaternary ammonium salt bactericides may cause contact dermatitis, scalding poisoning, and even death. Existing methods to determine quaternary ammonium salt bactericides are unable to meet current requirements owing to the lack of determination components.

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Organic solvents can be used to dissolve and disperse flavors, bactericides, preservatives, surfactants, oils, and coloring agents during the production of cosmetics. However, harmful chlorinated hydrocarbon organic solvents are found in cosmetics such as manicure products, anti-acne products, and perfumes. Long-term contact with such cosmetics will have an adverse effect on the consumers' health.

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A method for the determination of characteristic compound 3,5-dimethoxybenzoate-4-diglucoside (leptosperin) in manuka honey was developed by automatic on-line solid phase extraction-liquid chromatography-high resolution mass spectrometry (SPE-LC-HRMS). The samples were separated on a Dikma Diamonsil Plus C column (150 mm×4.6 mm, 5 μm) using the mobile phases of 0.

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A method of high performance liquid chromatography-quadrupole/electrostatic field Orbitrap high resolution mass spectrometry (HPLC-Q/Orbitrap MS) was developed to determine fructo-oligosaccharides in milk powder. The milk powder samples were dissolved in deionized water. Subsequently, an aqueous solution of zinc acetate was used to precipitate protein.

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A sensitive ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed and validated for simultaneous quantification of zinc pyrithione (ZPT) and climbazole (CBZ) deposited onto human scalp from anti-dandruff (AD) shampoos. Scrubbing with a buffer solution was used as the sampling method for the extraction of ZPT and CBZ from scalp. Derivatization of ZPT was carried out prior to UHPLC-MS/MS analysis.

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An HPLC method was developed for the determination of methylglyoxal in Manuka honey of New Zealand. The honey sample was dissolved in water and mixed with o-phenylenediamine solution for derivatization. After the reaction for at least 8 h in the dark at room temperature, the solution was filtered with 0.

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A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of five pyrrolizidine alkaloids (PAs) (monocrotaline, senkirkine, retrorsine, seneciphylline and senecionine) in honey. The honey samples were dissolved in 0.1 mol/L hydrochloric acid solution and a strong-cation exchange column was used to purify and concentrate the target analytes.

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A sensitive and specific ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the measurement of climbazole deposition from hair care products onto artificial skin and human scalp. Deuterated climbazole was used as the internal standard. Atmospheric pressure chemical ionization (APCI) in positive mode was applied for the detection of climbazole.

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A novel method for the determination of exogenous gamma-amylase residue in honey using liquid chromatography-isotope ratio mass spectrometry (LC-IRMS) was established. After pre-separation by gel column chromatography, the gamma-amylase in honey samples was separated from the sugars. The gamma-amylase was then used to catalyze maltose into glucose.

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A new method for honey adulteration detection using liquid chromatography/elemental analysis-isotope ratio mass spectrometry (LC/EA-IRMS) was developed. Based on the individual delta13C values detected for 38 authentic honey samples, the limits for the authentic honey samples were proposed: the delta13C difference between protein and honey (Deltadelta13C(P-H)) should be higher or equal to than -0.95 per thousand, the delta13C difference between fructose and glucose (Deltadelta13C(F-G)) should be from -0.

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This paper proposed a method with capillary zone electrophoresis (CZE) for analysis of eight heterocyclic amines in a commercial meat matrix. The influence of composition, pH and concentration of buffer, and applied voltage were investigated. A 5 mmol/L formic acid-ammonium formate solution at pH 2.

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A flow-injection chemiluminescent immunoassay system based on a novel transparent immunoaffinity reactor is proposed for the quantitation of alpha-fetoprotein. The reactor prepared with alpha-fetoprotein immobilized epoxysilane modified glass microbeads was used as an immunosensor for chemiluminescent detection. With a non-competitive immunoassay format, the proposed immunosensor system is a low cost, flexible and rapid assay for alpha-fetoprotein.

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