Articles by Limian Zhao - Chromatography Online
Articles by Limian Zhao

Limian Zhao


Articles
Agilent EU - Evaluating Inert Flow Path Components and Entire Flow Path for GC?MS-MS Pesticide Analysis
July 22, 2014

Flow path inertness is critical in pesticide analysis accuracy and precision, especially for active analytes such as organophosphate pesticides. Agilent?s Inert Flow Path, including Ultra Inert columns, liners and gold seals, and inert split/spiltless inlet, provides excellent surface inertness through the entire flow path.

Agilent NA - Evaluating Inert Flow Path Components and Entire Flow Path for GC/MS/MS Pesticide Analysis
July 22, 2014

Flow path inertness is critical in pesticide analysis accuracy and precision, especially for active analytes such as organophosphate pesticides. Agilent?s Inert Flow Path, including Ultra Inert columns, liners and gold seals, and inert split/spiltless inlet, provides excellent surface inertness through the entire flow path.

Agilent NA - Analysis of Fruit and Vegetable Pesticides by GC/MS/MS Using Agilent Inert Flow Path
April 23, 2014

The Agilent Inert Flow Path (IFP) solution was evaluated and validated thoroughly for the analysis of trace pesticides in various fruits and vegetables by GC/MS/MS. The results demonstrate excellent surface inertness for the entire GC flowpath and reduced negative impacts on the target analytes caused by surface active sites. Comparison results are also included.

Agilent EU - Analysis of Fruit and Vegetable Pesticides by GC–MS-MS Using Agilent Inert Flow Path
April 23, 2014

The Agilent Inert Flow Path (IFP) solution was evaluated and validated thoroughly for the analysis of trace pesticides in various fruits and vegetables by GC–MS-MS. The results demonstrate excellent surface inertness for the entire GC flowpath and reduced negative impacts on the target analytes caused by surface active sites. Comparison results are also included.

Agilent NA - Evaluating Inert Flow Path Components and Entire Flow Path for GC/MS/MS Pesticide Analysis
October 11, 2013

Flow path inertness plays a critical role in pesticide analysis accuracy and precision, especially for active analytes such as organophosphate pesticides. The Agilent Inert Flow Path, including Ultra Inert columns and liners, Ultra Inert gold seals, and inert split/splitless inlet, provides excellent surface inertness through the entire flow path, prevents loss of analyte response and peak share distortion, and thus delivers reliable qualitative and quantitative analysis of pesticides. Other inert supplies, including UltiMetal Plus flexible metal ferrules and capillary flow technology devices, are also highly recommended for pesticide analysis in complicated matrices.

The Use of Hollow Fibers in Liquid-Phase Microextraction
August 1, 2010

In this installment, the subject of LPME is reviewed, with emphasis on the use of hollow fibers.

Determination of Sulphonamide Antibiotics in Bovine Liver Using Agilent SampliQ QuEChERS EN Kits by LC–MS–MS
March 2, 2010

The procedure involves a rapid and efficient pretreatment with SampliQ QuEChERS kits. The homogenized liver sample was initially extracted in a buffered aqueous/1% acetic acid acetonitrile system with an extraction and partitioning step after the addition of salts. Finally, the sample was cleaned up using dispersive solid-phase extraction (dispersive-SPE). The final extracts were analysed by the sensitive and selective determination of all compounds in a single run using LC–ESI-MS–MS operating in positive ion multiple reaction monitoring (MRM) mode. Sulphapyridine was selected as the internal standard. The accuracy of the method, expressed as recovery, was between 53 and 93%. The precision, expressed as RSD, was between 2.1 and 16.8%. The established 5 ng/g limits of quantification (LOQ) were much lower than the respective maximum residue limit (MRL) for sulphonamide in animal food products (20–100 ng/g).

Determination of Quinolone Antibiotics in Bovine Liver Using Agilent SampliQ QuEChERS Kits by LC–MS–MS
March 2, 2010

The procedure involves a rapid and efficient pretreatment by SampliQ QuEChERS kits. The homogenized liver sample was initially extracted in a buffered aqueous, 5% formic acid acetonitrile system. An extraction and partitioning step was performed after the addition of salts. Clean-up was done using dispersive solid-phase extraction (dispersive-SPE). The final extracts allowed determination of all compounds in a single run using LC–ESI-MS–MS operating in positive ion multiple reaction monitoring (MRM) mode. Norfloxacin was selected as the internal standard. The accuracy of the method, expressed as recovery, was between 62 and 113%. The precision, expressed as RSD, was between 2.2 and 13.4%. The established limit of quantification (LOQ) was 5 ng/g and is significantly lower than the respective maximum residue limit (MRL) for quinolones in food producing animals.

Determination of Sulfonamide Antibiotics in Bovine Liver Using Agilent SampliQ QuEChERS EN Kits by LC–MS-MS
February 1, 2010

The procedure involves a rapid and efficient pretreatment with SampliQ QuEChERS kits. The homogenized liver sample was initially extracted in a buffered aqueous/1% acetic acid acetonitrile system with an extraction and partitioning step after the addition of salts.

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