Development of Analytical Methods using

Low Field NMR (LFNMR)

Luiz Alberto ColnagoEmbrapa Instrumentation

Brazilian AgriculturalResearch Corporation

Workshop Biorefineries 2010Recent Advances and New Challenges

Firjan, RJ, 10/11/2010

2

Nature 466, 554-556 (2010)

Food: The global farmWith its plentiful sun, water and land, Brazil is quickly surpassing

other countries in food production and exports. ….

Jeff Tollefson

25 % of GDP

60 Billion dollars (30% exp.)

“if one wants to know the primary reason of Brazil´s success in three words, they are Embrapa, Embrapa, Embrapa”,

4

Brazil 1st exporter

High variability

Commodities- millions of tons

Quality characterization/certification

High-throughput Agri-industrial sensor

- NMR –5

Superconducting Magnet

Transmitter /receiver

High resolution NMR Spectroscopy

Computer

HR-NMR application (solution)

Structure determination

Organic Synthesis

Natural Products

Materials

etc.

codeín

(a)Too expensive,

(b)too delicate for a factory environment

c)too slow for sample moving (2 m/s).

(d) Insufficient time to polarize the samples

(e) High skilled operators

distance (d= 5T1v ) in the magnet

(for v= 2 m/s, T1 = 1 s, d =10 m)

Why conventional NMR fail industrial sensor?Hills and Wright, JMR, 178,193-205, 2006

8

9

Too expensive,

too delicate

High skilled operators

Low resolution NMR - LRNMR

2- Insufficient polarization time

1-Too slow

LRNMR Problems

10

11

LRNMR Problems : Too slow

Poor S/N

Signal average:S/N=(n)1/2

Quantitative measurements = 5T1

Total time: seconds to minutes

Continuous Wave Free Precession (CWFP )

Azeredo et al, Anal. Chem. 72,2401-2405, 2000

n

Solution - LRNMR (S/N and T1)

Tr= 300 s

Mc=M0T2/T1+T2

Conventional NMR and CWFP

700 ms

0.3 ms

Soybean oilT1=140 msT2 =50 ms T2*= 0.5 ms

56 ms

29 ms

0.9 ms

CWFP=Tr<T2*

SSFP

-1.0 -0.5 0.0 0.5 1.0

(b)

H

G

F

E

D

C

B

A

t (msec)

SS

FP

Am

pli

tud

e

-1.0 -0.5 0.0 0.5 1.0

(b)

H

G

F

E

D

C

B

A

t (msec)

SS

FP

Am

pli

tud

e

-1.0 -0.5 0.0 0.5 1.0

(b)

H

G

F

E

D

C

B

A

t (msec)

SS

FP

Am

pli

tud

e

-1.0 -0.5 0.0 0.5 1.0

(b)

H

G

F

E

D

C

B

A

t (msec)

SS

FP

Am

pli

tud

e

-1.0 -0.5 0.0 0.5 1.0

(b)

H

G

F

E

D

C

B

A

t (msec)

SS

FP

Am

pli

tud

e

T1=T2, Mc=0.5M0

Azeredo et al, Anal. Chim. Acta 478, 313, 2003

Enhance S/N

a) Conventional

0 5 10 15 20

(a) time (ms)

0.0 0.2 0.4 0.6 0.8

(b) time (ms)

b) CWFP

0 20 40 60 80 1000

1

2

3

CW

FP

Am

pli

tud

e (

au

)

Oil % (W/W)

Azeredo et al, Anal. Chem. 72,2401-2405, 2000

Online CWFP NMR

Flow effect on CWFP signal

(Azeredo et al, Phys. Rev. E. 64, 016309-1, 2001)

Online NMR

Colnago et al, Anal. Chem. 79, 2382, 2007

Online NMR

99 seeds V=13 cm/s (+ 20,000 samples/h)

0 2 4 6 8 10 12 14

0

20

40

60

80

100

120

140

CW

FP

am

pli

tud

e (

au

)

Time (s)

r2 = 0.96

Biodiesel program, seeds high oil content100.000 SAMPLES

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

10 20 30 40 50 60 70 80 90

CWFP amplitude (au)

Oil

ma

ss

(g

)

Online Quality Analysis

CPMG –T2

0.0 0.5 1.0 1.5 2.0

Time (s)

(+ 1000 samples/h)

CPMG Analysis

0,0 0,5 1,0

0,0

0,5

1,0

D

C

BA

CP

MG

ech

o a

mp

litu

de

(a

u)

Time (s)

A-linseed; B- Soybean; C- Macadamia; D- Castor bean

Prestes et al,, Anal. Chim. Acta, 596, 325-329, 2007

39 42 45 48 51 54 57

42

45

48

51

54

b)

Ce

tan

e n

um

be

r fr

om

NM

R

Cetane number calculated from GC

Multivariate analysis (PLS)

Prestes et al, Anal. Chim. Acta, 596, 325-329, 2007

80 100 120 140 160 180

80

100

120

140

c)

IV

nu

mb

er

fro

m N

MR

IV number calculated from GC

25

High oleic acid peanuts (Margarine substitute)

3 x 4000 samples IAC

0 10 20 30 40

0,14

0,16

0,18

T2 (

ms)

Seed number

Mobile RMN

But not the for: inside-out, ex-situ, remote, single-sided, one-sided access Spectrometer

conventional

unilateral (U shape)

B0B1

NS

SN

N S NS

B0B1

Conventional NMR – Sample size depend on bore or gap size.

Ex. MOUSE (MObile Universal Surface Explorer) *

Unilateral RMN

Applications at Embrapa

Monitor biodiesel reaction

0 20 40 60 80 100

40

50

60

70

80

90

100

110

T* 2 (

ms)

Biodiesel Percentage0 20 40 60 80 100 120

40

50

60

70

80

90

100

110

T* 2 (

ms)

Reaction Time (ms)

Monitor biodiesel reaction

ANG. CHEMIE-INTERNATIONAL EDITION, 49 ,4133, 2010

Collaborations

Prof. Mario Engelsberg – DF/UFPe

Prof. Rodrigo B. V. Azeredo – DQO/UFF

Prof. Tiago Venâncio- DQ-UFSCar

Prof. Lucio L. Barbosa IQ-UFES

Graduate Students-USP

Fabiana Diuk

Antonio Marchi Netto

Pos-Doc.

Lucinéia Vizzotto

Acknowledgments to brazilian funding agencies

34

Thank you

colnago@cnpdia.embrapa.br35

MRI-Halbach1.2m Prepol, 0.5 principal magnet, 10 cm bore

Insufficient polarization time

www.spinlock.com.ar