Robert Ezeuka

Chemist (GS 12 Step 4)

U.S. Customs and Border Protection

07.2018 - Current

Company Overview: Laboratories and Scientific Services, New York Laboratory, 1100 Raymond Blvd, 5th floor Newark NJ 07102
As a Chemist under the 1320 series, my primary duties include, but are not limited to, chemical and physical analyses of samples of imported merchandise or seized materials submitted to the laboratory and writing reports, stating the technical findings, interpretations, and conclusions of such analyses
Sample analyses encompass the analysis of complex, new, or unknown samples in the laboratory or in the field to identify the sample using wet laboratory procedures or advanced analytical instrumentation (LC-MS, HPLC, GC-MS, GC-FID, FTIR, NMR, Raman, TGA, auto titrator, particle size analysis, UV -visible spectrometer, nitrogen analyzer for protein content) and troubleshooting the instruments
In efforts to identify misclassified onion products entering the country as 'other onions' (toasted/roasted) (HTS 2005, duty rate 4.5%) and not 'dehydrated onions' (HTS 0712, duty rate 26%) as part of investigation with head quarter assignment to the NY lab, I have searched the literature and optimized LC MS method to determine chemical differences between toasted and dehydrated onion
PCA unsupervised multivariate statistical analysis of the LC MS data showed the LC MS method can effectively distinguish differences between toasted and dehydrated onion
Developed a method and verified the use of UHPLC-MS Sciex X500 QTOF system for trace analyte detection of veterinary drugs (antibiotics) in complex biological matrices as a part of HSI investigation on imported shrimp
This method replaced the ELISA method which requires kits for each antibiotic screening
LC-MS method was used for screening hundreds of antibiotics in short period of time, using the library spectra of the newly purchased LC-MS Sciex X500 QTOF system in the New York laboratory, and helped in avoiding the use of expensive kits
Initiated the exploration of the LC MS method with Dr
Matthew Birck, Senior Science Officer of LSS, for Honey country of origin investigation by LC-HRMS method
Developed a method and verified the use of UHPLC-MS Sciex X500 QTOF system for country-of-origin screening of honey samples
Principal Components Analysis (PCA) in Sciex MarkerView software was employed to discriminate the resulting Mass spectral data so as to differentiate the origin of honey based on different geographic region
Verified the applicability of the LC MS method on 40 references honey samples from 6 different countries using the PCA unsupervised multivariate statistical analysis to examine differences between and within groups of samples
PCA analysis showed the LC MS method can effectively distinguish samples from different geographical region
Work is in progress to include more of the honey references available in the New York lab to build an LC MS data base that can serve as an additional tool for honey country of origin determinations
The analysis can be useful in facilitating lawful trade and protect revenue
Optimized a method and verified the use of UHPLC-MS Sciex X500 QTOF system for detection of Amitraz in standard honey samples as apart of ongoing HSI investigation to detect the pesticide in honey samples
Optimized a method and verified the use of UHPLC-MS Sciex X500 QTOF system for simultaneous detection of Phosphodiesterase Type 5 Inhibitors (drugs used for erectile dysfunction (ED), sildenafil, tadalafil, vardenafil in a seized sample
The retention time of the analyte were under 5 minutes and a total run time of 8 min
This is a much shorter than the approximately 45 min retention time in a one hour run time currently in use by the GC MS of the forensic team
Maintained LC MS instrument including cleaning curtain plate and orifice plate, tuning, instrument mass calibration over the desired mass range, checking the vacuum in the mass spectrometer, instrument setup and method development
Developed a procedure for the uncertainty budget measurement (as a part of ISO/IEC 17025:2017 recommendation) for the HPLC sugar method and provided advice to the food team branch chief
Implemented and validated the repeatability of Karl Fischer (KF) titration method for measurement of moisture contents in various food samples with novel, complex matrix containing high sugar contents
With the older routinely used method, it was impossible to implement moisture content determination in these types of samples due to caramelization from the sugar contents
Independently implemented the KF titration method from scratch for determination of water (moisture) contents in novel samples or those involving high complexity in multi-component foods containing starch, fat, and protein in different proportions and in different structure
The food samples analyzed included: giner pickel, giner pickel with garlic, sugar syrup, caramel, butter, milk powder, creamer, sugar grain and panela sugar
Implemented and validated the repeatability total dietary fiber content determination by non-enzymatic/gravimetric method of a food sample with low starch contents submitted to the food team as a part of total carbohydrate contents determination
Reviewed the literature and the official methods for dietary fiber determination and determined the appropriated method
These proper selections of the analytical method saved lab time and expense on the purchase of enzymes (NY2023-0150)
Developed and implemented a fast TLC method for detection of FDA approved food dye and natural dye in food samples such as a caramel sample submitted to the lab and other food samples that are suspected to contain artificial dyes
Validated the sieving methods for the rate passage of milling products through sieves with reference to tariff classification within chapter 11 for the Canada boarder service agency (was involved in an inter-governments agency collaboration)
Validated gel formation as an alternative method for detection of gum percentage contents for an antidumping order of xanthan gum
This new approach cut analysis time from 24 hours to four hours and involved only 8 steps compared to the 36 steps and save 20 hours of an analyst time
Developed and reviewed Standard Operating Procedures (SOPs) for existing and new analytical methods and instruments
Prepared SOP for identification of xanthan gum, detection of gum adulation and percentage of xanthan gum by dry weight as a part of the xanthan gum anti-dumping, operation of Sciex X500 QTOF LC-MS system, Karl Fischer (KF) Titration, Sieve analyzer and micropipettes
Reviewed SOP for nitrogen analyzer and titrator in the food team
Ensured the calibration/verification of analytical instruments, use of certified analytical reference standards and maintenance of the equipment prior use
Has been responsible for annual calibration of the New York laboratory micropipes since 2019 by an ISO accredited laboratory
Performed routine and non-routine maintenance on LC-MS, HPLC, GC-MS, auto titrator and nitrogen analyzer, including problem identification and resolution
Utilized GC–FID method for quantitative analysis of fatty acids composition and ethanol contents in complex food samples for trade rule enforcements (examples: palm oil sample, cream emulsion, and milk cream)
Conducted High Performance Liquid Chromatography (HPLC) analysis for sugar contents of food samples in diverse and complex food matric including butter, milk, pickled ginger with garlic, pickled ginger without garlic, caramel, milk powder, coffee cream, waffle powder, milk tea, pre-blend seasoning
Implemented the Ewers method, based on the partial acid hydrolysis of starch, followed by measurement of the optical rotation of the resulting solution, for determination of starch purity in food samples
Independently determined the approach and methods to use, taking into consideration the chemical characteristics of submitted samples or analytical requests, and plans and carries out the work
In the cases of novel samples assigned for analysis, reviewed the literature, and provide recommendation on the appropriate analytical method to be used to the branch chief for approval and implementation
Reviewed the literature on accurate identification of plant species based on unique marker compounds for presumptive identification of plant material samples and provided recommendation to the food team branch chief on the appropriate analytical method to be used for approval and implementation (example of samples analyzed this way included those claimed to be grapefruit powder, yucca powder, Ginger powder, mariground flower etc.)
Performed technical review of analysts' reports in the food team for adequacy of test methods, reproducibility and accuracy of results, conformance of methods and results with CBP policies since November 2021
Have been the sole technical reviewer of lab reports on the NMR analysis of samples based on the country-of-origin study reports and data of standard honey samples to be used for Country-of-Origin database of honey samples in the food team
Also reviewed technical reports on authenticity of honey samples by NMR method
Have been the sole analyst performing xanthan gum identification, xanthan gum purity determination (Xanthan gum anti-dumping) and sieve analysis for determination of particle size distributions of food samples in the last three years in the food team of the New York laboratory
Have been determining acetic acid percentage in Shushi ginger samples
Provided classification technical opinion to national import specialists on Harmonized Tariff Schedule (HTS) of PVC plasticizers from Brazil (N324111 and N325595)
Provided classification technical opinion on pharmaceuticals including on pneumococcal polysaccharides vaccines, Spray-Dried Dispersion (SDD) Mixed Bulk Drug Product consisting of ivacaftor and tezacaftor, the use of various pharmaceutical impurity reference materials in pharmaceutical companies, wash buffer solution classification as diagnostic or laboratory reagent and elderberry extract classification
Also provided technical opinion to determine the proper HTS classification for the list of methamphetamine and fentanyl precursors and the 2020, 2021, 2022 International Nonproprietary Names for Pharmaceutical Substances (INN) as part of head quarter assignment through the food team branch chief
Assessed and provided resource budgetary needs and communicated the spending plan details to Branch Chief including funding towards operations, equipment (was actively involved with the purchase of the new LC-MS Sciex X500 QTOF system), training and development, travel, quality-related services, and supplies (such as HPLC grade solvents, reference standards, reagents, LC MS grade solvents and reagent (formic acid), mass spectrometry calibration solutions and the columns)
Successfully completed annual proficiency testing in the sugar analysis, moisture, and protein content determinations since 2019
Have been storing samples for one and half years (from February 2021 to August 2022) after analysis into the storage room and then disposing samples in LIN appropriately for the food team
Participated as an internal auditor to ISO/IEC 17025:2017 ANAB accreditation of the New York lab in 2022 and 2023, was interviewed on food team methods by analysts that were internal auditors and by external auditor from ANAB, interviewed analysts on various methods such as: Started cross training to be gauger auditor, Forensic method (Seized Drugs: Quantitative Determination Solid UV/Vis Spectroscopy (FO-20)) and Textile methods (Weave Construction Microscopy (ISO 7211-1) and number of threads per unit length microscopy, Micrometer (ISO 7211-2)), as well as being interviewed and demonstrating methods for the audit
Laboratories and Scientific Services, New York Laboratory, 1100 Raymond Blvd, 5th floor Newark NJ 07102

Summary

Overview

Work History

Chemist (GS 12 Step 4)

Education

Master of Science - Molecular Biology

Bachelor of Science - Chemistry

Skills

Certification

Specialized Training

Affiliations

Testimony - Within Last Four Years

Additional Qualifications

Timeline

Chemist (GS 12 Step 4)

Master of Science - Molecular Biology

Bachelor of Science - Chemistry

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