The use of High Resolution Mass Spectrometry and Statistical Analysis in the Investigation of Food Authenticity - Waters Corporation Food Research

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The Use of HRMS and Statistical Analysis in the Investigation of Food Authenticity

Basmati Rice


Contents

Overview

Experimental Workflow

Samples and Sample Preparation

Data Collection and Processing

Initial Results

Summary and Conclusions


Why ?


For years, Indian traders have been passing off a

lesser quality rice, CSR 30, as the world's finest

long-grained, aromatic rice, Basmati, in key markets

like the US, Canada and the EU. In the process, the

rice exports enjoy the duty exemption accorded to

pure Basmati in the EU, thousands of consumers

get duped both in the domestic and export

markets, and the stock of traditional grain gets

depleted on Indian farms.

Basmati Rice Economic Adulteration

In Britain, the Food Standards Agency found in 2005 that

about half of all basmati rice sold was adulterated with other

strains of long-grain rice, prompting rice importers to sign

up to a code of practice.[8] A 2010 U.K. test on rice supplied

by wholesalers found four out of 15 samples had cheaper

rice mixed with basmati, and one had no basmati at all

http://en.wikipedia.org/wiki/Food_Standards_Agency

http://en.wikipedia.org/wiki/Basmati


Analysis Workflow


Analysis Workflow


Samples and Sample Preparation

10 g dry rice in headspace/SPME vial

3 Replicates of each sample

A pooled composite sample

Randomized sample list

Sample Description Sample ID

1 Basmati Manufacturer 1 BAS M1


3 Long Grain Manufacturer 3 LG M3


5 Jasmine Manufacturer 5 JAS M5


7 Jasmine Manufacturer 4

JAS M4

8 Composite Sample Pool


Analysis Workflow


Instrument Conditions: SPME Autosampler

Supelco SPME gray hub notched

Divinylbenzen/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS)


Instrument Conditions: GC

Column: 30 m DB-5


Analysis Workflow


Universal Source Technology …High Performance and simplicity of operation

IonKey Source

with nanoTile Technology.

Plug & Play nanoFlow

APGC – Atmospheric Pressure

Gas Chromatography

ASAP – Atmospheric Pressure

Solids Analysis Probe

MALDI nanoFlow ESI APCi ESCi APPI TRIZAIC ASAP APGC

Wide Range of Ionization Options


Instrumentation Setup


Mass Analyser GC Oven

N2 make-up gas delivered through transfer line interior

N2 meets GC eluent flow at transfer line tip

With thanks to Paul Silcock

APGC – How it works


Comparison of EI vs APGC spectrum of Chlorfenapyr

MSE Low energy

MSE High energy

EI Library spectrum

APGC spectrum

C15H11BrClF3N2O

http://www.chemspider.com/Molecular-Formula/C15H11BrClF3N2O










Instrument Conditions:

SYNAPT G2-Si

Source Conditions

HDMSE Acquisition Mode


MSE

Fragmentation in Trap or

transfer

Alternate Low and High

Energy Scans


MSE – no mobility separation

Imazalil from an EU Mandarin PT Sample

Low Energy

High Energy


Fragmentation in Transfer

Mobility separation

Alternate Low and High Energy Scans

precursors and products have same drift

time

HDMSE


Transfer Fragmentation

Drift time

Precursor ions

m/z

Precursor and products are time aligned

Drift time

m/z

Precursor ions


IMS

-9 -8 -7 -6

TOF MS LC

-5 -4 -3 -2 -1 0 1 2 3 4 n 10n seconds

Ion Mobility: an Orthogonal Dimension of Separation


HDMSE – MSE with a mobility separation

Low Energy

High Energy


Analysis Workflow


Progenesis QI - Workflow

Alignment

Peak Detection

Component Intensity

Comparison

Identification

Statistics

Deconvolution


Initial Results: PCA

Basmati ?

Jasmine ?

Long Grain ?


PCA to S Plot


S Plot

Common Markers

Markers prominent in Long Grain

Marker Importance

Mark

er

Confidence

Markers prominent in Basmati


Markers of Interest


Correlation Analysis


Correlation Analysis: Basmati Markers

Prominent markers in basmati


Correlation Analysis: Long Grain Markers

Prominent markers in long grain


Finding Markers of Interest

So, what now?


Elucidation

Elucidation by:

— Elemental Composition

— Integrated Chemspider Search

— Fragment Match


Elucidation


Elucidation


Elucidation


Elucidation


Elucidation


Progenesis QI Database Search



The components of interest can be searched

against a number of user customizable

databases

A list of potential identifications is generated

and scored using mass accuracy, isotope

distribution, retention time, drift time and

fragmentation

If the data base contains structures theoretical

fragmentation is performed and a fragmentation

score is used to rank the potential identifications





HDMSE

MSE


Further Database Search Results








Finding Markers of Interest

X


Waters “Omics” Research Platform Solutions with Progenesis QI Informatics

Proteomics

Metabolomics Lipidomics

Authenticity

Plant/Food Profiling

Plant Metabolomics


Research to Routine

Xevo G2-S Q-ToF SYNAPT G2-Si HDMS

X


Summary of Key Information Points

Identification: Elucidation or via database search. Drift and

time aligned HDMSE data facilitates the process.

Isolation: Progenesis QI alignment and peak picking

algorithms ensure markers of all intensities are correctly

tracked across all samples.

The principle behind the experiments has remained the same.

These advancements in hardware and informatics are

reducing the size of the task

Detection: HDMSE acquisition: High Specificity, enhanced

peak capacity over standard MSE acquisition.


So What Now for Basmati Rice?

Method development and proof principle using off the shelf samples.

Now require a collaborator with access to well characterised samples

that are known pure/adulterated/spiked/suspect.

Investigate the use of relevant available databases for facile marker

searching.

Ideal situation is to get from research to quality control.

The principle of detection, isolation and identification can be used for

other applications

— Contamination investigation

— Good tasting product vs bad

— Food packaging leachables extractables

— Food Metabolomics


Questions ?

The use of High Resolution Mass Spectrometry and Statistical Analysis in the Investigation of Food Authenticity - Waters Corporation Food Research

Science

waters corporation

basmati manufacturer

grain rice

pure basmati

rice exports

aromatic rice

rice importers

cheaper rice