Kai Zhang

Dr. Kai Zhang

US Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, HFS-717, 5001 Campus Drive, College Park, MD 20740, USA
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Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 August 2020 in Toxins
Verified
Journal Article
Open access
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KZKai Zhang
Kai Zhang
KBKaushik Banerjee
Kaushik Banerjee
As a class of mycotoxins with regulatory and public health significance, aflatoxins (e.g., aflatoxin B1, B2, G1 and G2) have attracted unparalleled attention from government, academia and industry due to their chronic and acute toxicity. Aflatoxins are secondary metabolites of various Aspergillus species, which are ubiquitous in the environment and can grow on a variety of crops whereby accumulation is impacted by climate influences. Consumption of foods and feeds contaminated by aflatoxins are hazardous to human and animal health, hence the detection and quantification of aflatoxins in foods and feeds is a priority from the viewpoint of food safety. Since the first purification and identification of aflatoxins from feeds in the 1960s, there have been continuous efforts to develop sensitive and rapid methods for the determination of aflatoxins. This review aims to provide a comprehensive overview on advances in aflatoxins analysis and highlights the importance of sample pretreatments, homogenization and various cleanup strategies used in the determination of aflatoxins. The use of liquid-liquid extraction (LLE), supercritical fluid extraction (SFE), solid phase extraction (SPE) and immunoaffinity column clean-up (IAC) and dilute and shoot for enhancing extraction efficiency and clean-up are discussed. Furthermore, the analytical techniques such as gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), capillary electrophoresis (CE) and thin-layer chromatography (TLC) are compared in terms of identification, quantitation and throughput. Lastly, with the emergence of new techniques, the review culminates with prospects of promising technologies for aflatoxin analysis in the foreseeable future.

31 August 2018 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
JWJon W. Wong
Jon W. Wong
JWJian Wang
Jian Wang
WCWillis Chow
Willis Chow
RCRoland Carlson
Roland Carlson
ZJZhengwei Jia
Zhengwei Jia
JCJames S. Chang
James S. Chang

3 January 2017 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
KZKai Zhang
Kai Zhang
MSMatthew R. Schaab
Matthew R. Schaab
GSGavin Southwood
Gavin Southwood
ETElizabeth R. Tor
Elizabeth R. Tor
LALinda S. Aston
Linda S. Aston
TBTimothy H. Begley
Timothy H. Begley

5 February 2015 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
PYPaul Yang
Paul Yang
JCJames S. Chang
James S. Chang
JWJon W. Wong
Jon W. Wong
KZKai Zhang
Kai Zhang
AKAlexander J. Krynitsky
Alexander J. Krynitsky
JWJian Wang
Jian Wang

23 April 2018 in Food Additives & Contaminants: Part B
Verified
Journal Article
Closed access
KZKai Zhang
Kai Zhang
BFBrenna M. Flannery
Brenna M. Flannery
COCarolyn J. Oles
Carolyn J. Oles
AAAnthony Adeuya
Anthony Adeuya
The objective of this study was to conduct a mycotoxin survey of commercial infant/toddler foods (cereals and teething biscuits) and breakfast cereals in the United States. A total of 215 retail samples were collected from three geographical locations and analysed for aflatoxins, fumonisins, deoxynivalenol, HT-2 toxin, ochratoxin A, T-2 toxin, and zearalenone using a stable isotope dilution liquid-chromatography tandem mass spectrometry (LC-MS/MS) method. One or more mycotoxins were found in 69% (101/147) of the infant/toddler foods and 50% (34/68) of breakfast cereals. Mycotoxin co-occurrence was observed in 12% of infant/toddler foods and 32% of breakfast cereals. However, the concentrations of detected mycotoxins were lower than the current FDA action and guidance levels. Aflatoxins and HT-2 toxin were not detected in any of the samples, while deoxynivalenol was the most frequently detected mycotoxin. Rice-based cereals appeared to be less susceptible to mycotoxin contamination than other cereal types.

31 October 2008 in Food Additives & Contaminants: Part A
Verified
Journal Article
Closed access
KZKai Zhang
Kai Zhang
GNG.O. Noonan
G.O. Noonan
TBT.H. Begley
T.H. Begley
A gas chromatography-ion-trap tandem mass spectrometry procedure was developed for the determination of 2,6-diisopropylnaphthalene (DIPN) and n-dibutylphthalate (DBP) in domestic and imported paper packages and food sold in US marketplaces. The procedure involved ultrasonic extraction with dichloromethane, followed by analysis with the gas chromatography-ion-trap tandem mass spectrometry. Calibration curves for DIPN and DBP were achieved with concentrations ranging from 0.01 to 10 µg ml−1 and the corresponding r 2 values were 0.9976 and 0.9956, respectively. In most of the fortified samples the recoveries were higher than 80% with a relative standard deviation (RSD) <10%. Using this procedure, it was found that less than 20% of the tested domestic packages and more than 60% of the tested imported food packages contained both DIPN and DBP. The concentrations of DIPN and DBP ranged from 0.09 to 20 mg kg−1 and 0.14 to 55 mg kg−1, respectively, with most of the DINP and DBP levels lower than 20 mg kg−1. DIPN was not detected (<0.01 mg kg−1) in 41 food samples and DBP was only detected in two domestic and four imported food samples with concentrations ranging from <0.01 to 0.81 mg kg−1.