News from GERSTEL GmbH & Co. KG · Eberhard-Gerstel-Platz 1 · 45473 Mülheim an der Ruhr · Germany · Phone + 49 (0) 208 - 76503-0 · gerstel@gerstel.com
No. 16

Metabolomics

Automated Sample
Preparation for
Lipidomics

Forensic Science and Toxicology

Automated determinationof THC, CBN and CBD in
human hair

Flavor, Fragrance, and Odor Analysis

A new Twist: Free acids
and phenols

CONTENTGERSTEL Solutions worldwide 16

Dear Reader,

We hope you will enjoy the magazine.
Sincerely,
GERSTEL Management

2

NRW State Governor visits GERSTEL
Hannelore Kraft, Governor of the State of North Rhine-Westphalia (NRW),
paid GERSTEL a visit to get first-hand information about the conditions
under which technology companies in the German “Mittelstand” operate. . 3
Material and Environmental Analysis

A Sea of Polymers
Microplastic particles in the marine environment could have a bigger impact
than previously thought: Pyrolysis GC/MS helps with the characterization. .... 4
Metabolomics (Part 2)

Sample Preparation with the
GERSTEL MPS Dual Head WorkStation
Part two in our series looks into the field of lipidomics focusing on
automated Lipid Fractionation using SPE. .................................................................... 8
Automation Technology

Looking for Automation?
What should you look for and what should be considered before buying
a new autosampler for GC/MS and LC/MS – an overview ............................. 11
Automated Liquid-Liquid Extraction (LLE)

Speeding up the workflow
In addition to SPE workflows, the GERSTEL MultiPurpose Sampler(MPS) can perform fully automated liquid-liquid extraction. ........................... 14
Forensic Science and Toxicology

Automated determination of THC, CBN and CBDin human hair
In a joint research project with an Institute of Forensic Medicine,
GERSTEL has successfully automated a validated method for THC,
CBN and CBD in hair. .......................................................................................................... 15
Forensic and Pharmaceutical Analysis

What a drop of blood reveals
In blood analysis, Dried Blood Spot (DBS) sampling and analysis isa convincing alternative – especially when it is automated using
the GERSTEL MPS. ................................................................................................................ 17
Flavor, Fragrance, and Odor Analysis

A new Twist: Sensitive SBSE determinationof free acids and phenols
The US-based flavor analysis expert Ray Marsili, Ph.D. has expanded thescope of SBSE analysis of food, beer and sweaty garments. .......................... 18
Mycotoxin Monitoring

Nine steps forward
Images (Frontpage): Dr. Malte Reimold, Jan Garbe-Immel / GERSTELThe task may be to monitor food safety bydetermining individual identities and amounts ofvarious chemical compounds in food or beverages;
or to analyze blood, urine or hair for residues ofdrugs and pharmaceutical compounds; or evento determine the type and amount of microplastic
particles in environmental samples. In
chemical analysis as in competitive sports,
the credo is maximum efficiency, highest
productivity and sustainable use of available
resources.
Analytical laboratories that want to meetand exceed current and future requirements
should turn to simple-to-use, reliable
automation, ideally requiring only minimal
Eberhard G. Gerstel
amounts of sample and solvent to reach low
limits of detection.
GERSTEL is among the leading providersof automation for GC/MS and LC/MS,
specializing in sample preparation and-introduction among other things. GERSTEL
solutions are used in a broad range ofapplication areas. If you are considering
automating parts of your laboratory work,
Holger Gerstel
or if you are looking for an autosampler, thearticle „Looking for Automation?“ on page
11 offers valuable tips and insights on what
to look for.
We hope that this issue of GERSTEL
Solutions worldwide magazine will give
you food for thought and stir your interestin starting a conversation with our experts.
GERSTEL partners and representatives inyour area can be found under www.gerstel.
Ralf Bremer
com or by sending a mail to gerstel@gerstel.
com. Contact details are also listed on the back coverof this magazine.
GERSTEL Solutions worldwide No. 16 consistsof a series of informative and easy-to-read articles
from a broad range of analytical laboratories, mostof the work has been done by GERSTEL users. The
content is listed on this page. Additional articles andmaterial can be found under www.gerstel.com.

Company News

Determining nine mycotoxins in one run without relying on
immunoaffinity cartridges or human intervention?
More about the SPE-LC-MS/MS multi-method on page ................................... 22
Company NewsGERSTEL expands in Southeast Asia
Ever increasing demand for intelligently automated solutions from GERSTEL
made it necessary to expand into larger offices in Singapore. ........................ 26
Automated Sample Preparation

The perfect blend
By automating and miniaturizing the blending process Symrise, theGermany-based global player increased the productivity of its flavor
and fragrance development. ............................................................................................ 28
News .......................................................................................................................... 25, 30, 31
Application: Conducting E&L studies more efficiently ......................... 31
Preview – Coming up in the next issue ........................................................... 32
Imprint ...................................................................................................................................... 32

GERSTEL Solutions worldwide – No. 16

Company NewsNRW State Governor visits GERSTEL
Hannelore Kraft, Governor of the State of North Rhine-Westphalia (NRW), paid GERSTEL a visit toget first-hand information about the conditions under which technology companies in the German“Mittelstand” operate and to ask the company to add even more young people to its vocational
training program. With 18 million inhabitants, NRW is the most populous of the German states(Länder) and the one with the largest economy.
By Guido Deussing

Images: GERSTEL

I

through an official exam to become
f you measure the Germana certified professional. The political
Small and Medium Enterprisclass is well aware that the “Mitteles (SMEs) by their number, theirstand“ is the educator of the nation
revenues, added value, and by
where four out of five professionals rethe money they invest each year,
ceive their training. Governor Kraft’s
these companies make up the maappeal to GERSTEL was to provide
jor group of players in the thriving
even stronger support for her proGerman economy. In Germany,gram. GERSTEL currently has five
SMEs are referred to as belongsuch trainees and has a history of taking to the “Mittelstand” or grouping them on as full employees whenof medium sized companies.
they pass their exams.
In 2014, the German Feder- The Governor means business: NRW Governor Hannelore
Kraft visited GERSTEL to listen, learn, and garner support
GERSTEL has 200 employees
al Bureau of Statistics published for her political programs helping school graduates join thea report: „Mittelstand, the en- ranks of trained professionals. Mrs. Kraft is shown here with world-wide, 160 of these are in GerR. Gerstel (front), Eberhard G. Gerstel (center) andmany mainly at Headquarters in Mülgine of the economy, numbers Holger
General Manager Ralf Bremer to the right.
heim an der Ruhr, NRW. About one
and facts about German SMEs“.
third have a B.Sc. or higher education
These SMEs generate 36 percent
including 14 Ph.D. scientists. Two thirds have professionalof the total revenues of all German companies and 55 percent
training including fine mechanics and office/commercial staff,of the added value. In addition, the SMEs are responsible formany of whom received their training in the company. “We
16.8 Million, or 62.3 percent, of the employees who contribtrain and qualify employees in order to support and extend
ute to the German equivalent of Social Security taxes. Thesethe GERSTEL know-how”, says Holger Gerstel, President
numbers are out of a total population of 81 Million (2014).
and co-owner of theThis means that politicians should pay attencompany. Governor
tion to and support SMEs, which form a key pillar of
Kraft and GERthe German economy and the social fabric. This is exSTEL upper manactly what Governor Hannelore Kraft of North Rhine
agement stressed
Westphalia was doing when she visited GERSTEL
the importance of
Headquarters in September 2015. Incidentally, Kraft means
the dual educational
Force in German. The NRW Head of State wanted to getsystem to ensure
first-hand
inprofessional trainformation about
ing on a high level.
the operations of
The system is recGERSTEL,aognized as uniqueglobal player in theand many nations Ralf Bremer (2nd from left) shows Governor Kraft the Thermal
field of LaboraDesorption Unit (TDU), the centerpiece of many GERSTEL systems.
are looking to repli- Application Chemist Jochen Vandenberg (left) demonstrated thetory Instrumentacate it. “GERSTEL use of the TDU in combination with the GERSTEL Twister® fortion for Chemical
has received several flavor and fragrance analysis.
Analysis.
In
addition, delegations from
China who wanted to study the German system of profesGovernor
Kraft
sional training and to see how it is implemented in practice”,
wanted to drum
GERSTEL core competence fine mechanics:
says Eberhard G. Gerstel, President and Co-Owner. Manup
supportfora
For some products, a magnifying glass helps
to appreciate the fine details shown to theagement ensured Governor Kraft that they will maintain andState Government
Governor by Dennis Arkeveld (center) fromexpand GERSTEL’s role as a leading company in its fieldproject
called“No
the GERSTEL production team.
while supporting and training young people for their profesgraduation withsional future. However politics should refrain from addingout continuation, transition from school to professional life
restrictions to SMEs but rather let them focus their energies
in NRW”. The idea behind the slogan is to pave the way
on core competences, allowing them to retain and gain comfor school- or high school graduates to enroll in professional
petitiveness in the global marketplace.
training and education programs in companies. The German
two-pronged approach (“Duales System”) combines training
and work in the company with classes at professional or vocational schools. At the end of the process, the trainee goes
GERSTEL Solutions worldwide – No. 16

3Material and Environmental Analysis

A Sea of Polymers
Microplastic particles in the marine environment could have abigger impact than previously thought: To get an idea of the extent
of the plastic waste pollution in the marine environment, and of how
quickly, if at all, it breaks down, science must rise to the challenge
and find ways to determine qualitatively and quantitatively what is
floating amongst the aquatic wildlife that makes up a good part ofour food supply. Pyrolysis GC/MS has been found to be a useful tool
for the characterization of microplastics in environmental samples.

Image: istock / enviromatic

By Guido Deussing

4

GERSTEL Solutions worldwide – No. 16

uring the International Coastal Cleanup in 2013,
648,015 volunteers worked along a stretch of aroundthirteen thousand miles of ocean coastline to remove
more than 5,500 tons of waste. The top ten waste items
were: Cigarette butts (913 tons), paper candy wrapping(794 tons), plastic bottles (426 tons), plastic caps and lids
(385 tons), plastic soda straws (252 tons), standard plastic
shopping bags (200 tons), glass bottles (179 tons), otherplastic bags large and small (176 tons), paper bags (167
tons), and beverage cans (154 tons) [1].
There is no way to correlate the recorded amount ofthese different types of waste to the total amount of waste
released annually into the oceans, but it does paint a grim
picture if one considers that we are only looking at the tipof the iceberg. Another large source of pollution is plastic
micro beads (less than 5 millimeters in diameter) used inpersonal care products mostly as exfoliating agents. During use they enter the waste water stream; however, they
pass though waste water treatment plants and end up in
our water ways and oceans where fish ingest them at an
alarming rate. It seems safe to assume that plastics are oneof the major sources of environmental pollution. Not justenvironmental action groups, but also polymer material
producers see cause for concern and the need for action
as an increasing number of scientific journal papers andreports are referenced in the press documenting the detrimental effects of microplastics on the environment [2].
What then needs to be done – and what can the individual consumer do to avoid contributing to microplastics
pollution or even to help improve the situation?
A responsible and sustainable use of polymer materials is a good start for individual consumers, companies
and organizations alike. On a grander scale, well organized collection and recycling systems must be available.
Various projects have been initiated with the aim of reducing the problem of waste in the oceans [2-6]. In themeantime, inland waterways and water bodies are also
becoming the focus of attention since they seem to be
impacted significantly as well [7-8].
Obviously, for any long term strategy to have a chanceof success, it needs to be built on solid and reliable data.
At this time, too little is known about transport routes,
transformation processes, as well as effects and whereabouts of polymer residues in the environment. The scientific community is working to close this knowledge gap
with a special focus on microplastics [7, 9-12].

The big problem posed by thetiniest particles
Polymer materials are very rugged. Even when exposed toenergy-rich solar radiation, chemicals, mechanical force,or microbial attack, they never really seem to degrade or
GERSTEL Solutions worldwide – No. 16

disappear from the environment. Sooner or later, polymer
materials become brittle and are ground into ever finerparticles until they end up in the microplastics range.
Microplastic particles, due to their small size, ranging
from a few micrometers to a few millimeters, and theirirregular shape and color, are often mistaken for food andare ingested by aquatic organisms and sea birds.
Increasingly, substantial amounts of polymer fragments are being found in the digestive tracts of deadseabirds. Whether the microplastic particles caused thedeath of the animals is uncertain. Nevertheless, it is notunreasonable to assume that animals which often ingest
plastic material could suffer from malnutrition. Scientists predict that in 2050 we will find plastic residues inaround 80 percent of all seabirds. Further, microplastic
particles can contain unhealthy or toxic additives as wellas pesticides, heavy metals or other toxins that are concentrated in the polymer from the surrounding environment. Since humans are at the top of the food chain this
could eventually become a threat to us as well.

International efforts to learn more
The European Commission’s Marine Strategy Framework Directive (MSFD) [13] focuses on protecting theseas and on managing natural marine resources efficiently. According to the MSFD, the type and compositionof micro particles, and microplastic particles in particular,need to be characterized. This is exactly what researchers at the Universities of Osnabruck and Darmstadt, both
located in Germany, have set out to do. As part of theirresearch [10, 11], Professor Elke Fries and her colleagues
investigated marine microplastic particles, which they
had extracted from sand samples collected on the North
Sea Island of Norderney, Germany. In order to determine the material composition of the microplastic particles collected as well as any additives used or pollutants
that had been absorbed by the particles, Prof. Fries andher colleagues turned to pyrolysis-GC/MS as the firstscientists ever to do so for this type of sample[10-12]. Previously, mainly spectroscopic
methods had been used to establish
Plastic waste floating in surface water ismistaken for food or ingested with food byaquatic organisms and seabirds. Scientists
speculate and project that in 2050, plastic
residues will be found in almost all seabirds.

Image: istock / Micha Klootwijk

D

5

Images: Prof. Christian Laforsch, Universität Bayreuth

Comparing a
picture taken withvisible light anda fluorescencepicture brings
the truth to thefore: The red
dots in the latter(right hand side)
are microplastic
particles in thedigestive tract of
the animal.

Image: GERSTEL / Wolfram Schroll

the structure and composition of polymers, Fries et al.
wrote, and organic additives were extracted using supercritical fluid extraction or Soxhlet extraction. For
polymer particles that are not easily dissolved, extracted or hydrolyzed, pyrolysis GC/MS can be a highly
useful complementary technique.
Pyrolysis GC/MS serves to provide structural information about macromolecules based on the fragments formed in a controlled thermal decomposition
process [14].
Serial pyrolysis is performed in two or more steps.
Initially, volatile compounds are thermally extracted
from the sample at a relatively low temperature. The
technique is referred to as thermal desorption. Following the first step, the same sample is pyrolyzed at ahigher temperature; ideally both steps are performed
without the need to reconfigure the instrument. By collecting GC/MS data for both steps, organic additives
and pyrolysis breakdown products can be determined
during a single sample run. As Prof. Frieset al. note, this is a very efficient means ofgathering information on both polymer
type and the additives it contains.

The TDS is well suited for performing serial pyrolysis GC/MS on a small
number of samples. When the TDS is fitted with a special module, the PM
1, it can be used for both thermal desorption and pyrolysis on the same
sample. When a larger number of samples need to be analyzed by serial
pyrolysis GC/MS, the Thermal Desorption Unit (TDU) in combination with
the MultiPurpose Sampler (MPS) shown here is the best option.

6

For their work, the researchers used a 7890 GC (Agilent Technologies) equipped with a Cooled Injection
System, PTV-type inlet (GERSTEL CIS) and a Thermal Desorption System (GERSTEL TDS) fitted with a
Pyrolysis Module ( GERSTEL PM 1). This instrument
combination is well suited for performing pyrolysis andserial pyrolysis manually. If a larger number of samples
need to be analyzed, the process can readily be automated using the GERSTEL MultiPurpose Sampler (MPS)in combination with a GERSTEL Thermal Desorption
Unit (TDU) and the GERSTEL PYRO module.

Technical and application details
Fries et al. performed the analysis as follows: A microplastic particle was placed in a pyrolysis sample tube
and transferred to the PM 1. The PM 1 was then inserted into the TDS and sealed using the cone locking
mechanism. The TDS temperature was set to 40 °C andheated at a rate of 10 °C/min to 350 °C (10 min); during this period, volatile compounds were thermally extracted from the matrix and cryofocused in the CIS at-50 °C; subsequently, the CIS was heated from -50 °C at
a rate of 12 °C/min to 280 °C (3 min) and the analytes
transferred to the GC column (30 m HP 5MS with 250
μm ID and 0.25 μm film thickness). The GC oven temperature program used was 40 °C initial temperature;
15 °C/min to 180 °C; 5 °C/min to 300 °C (12 min).
Helium carrier gas was used. After the GC/MS run for
the volatile compounds had been completed, the sample
was pyrolyzed as follows: The TDS was set to a starting
temperature of 60 °C (1 min) and heated at a rate of 180°C/min to 350 °C. Pyrolysis was then performed in the
PM 1 at 700 °C (1 min).
The pyrolysis fragments formed were transferred to
the CIS and cryofocused using liquid nitrogen. Following the pyrolysis step, the fragments were then transferred from the CIS to the GC column using a temperature program as described above. Mass selective
detection followed using a MS 5975C from Agilent
Technologies. In addition to the chromatogram of the
GERSTEL Solutions worldwide – No. 16

Image: istock / Anschiwil; Fries et al.

Overlay pyrograms enable easy comparison ofstandard polymers (Purple: Standard low density
Polyethylene [LDPE]) with those found in environmental samples (black: Polyethylene C.).

volatile compounds, the pyrogram containing the pyrolysis products was collected.

Obtaining valuable information efficiently
Based on mass spectral libraries as well as comparison ofretention times and mass spectra of analyzed standards,
Fries et al. were able to identify a variety of plastic additives in the microplastic particles found on the North
Sea island of Norderney. Among these were plasticizers,
including the phthalates DEHP, DBP, DEP, DIBP and
DMP, the antioxidant 2,4-di-tert-butylphenol, and aromatic compounds such as benzaldehyde, which is added
as fragrance to cosmetics and to polymers directly.
The polymer type was determined by the researchers
by comparing pyrograms from the collected microplastic
particles with those from standard polymers. They identified polyethylene (PE), polypropylene (PP), polystyrol(PS), polyamide (PA) as well as chlorinated and chlorosulfonated PE.
Concerning their method for the determination oforganic polymer additives, the researchers came to thefollowing verdict: Compared with traditional solvent extraction based methods, the serial pyrolysis method offers the advantage of determining both the volatile compounds in the material, including additives, and the typeof polymer in a single process step – without having to use
solvents and without background contamination from thematerial. The pyrogram is free of interfering compounds
that offer no structural information since these have been
removed in the thermal desorption step.

Final words from the researchers
Serial pyrolysis GC/MS has sufficient sensitivity to determine plasticizers, antioxidants, and fragrances in microplastic particles with a mass of less than 350 μg. This
makes it possible to determine the chemical, toxicologicalor endocrine disrupting risk potential of such particles. According to Fries et al., Serial pyrolysis could be used for the
implementation of the Marine Strategy Framework DirecGERSTEL Solutions worldwide – No. 16

tive (MSFD) by enabling the determination of the chemicalcomposition of microplastic particles. Just for good measure,in addition to the organic compounds, the researchers also determined the following inorganic polymer additives: Titaniumoxide, as well as barium-, sulfur- and tin compounds [10].

References[1] http://www.oceanconservancy.org/our-work/marine-debris/iccdata-2014.pdf (14.11.2015)[2] Marine litter solutions (www.marinelittersolutions.com, 14.11.2015)[3] Marine Debris Solutions (www.marinedebrissolutions.com,
14.11.2015)[4] Fishing for litter (www.nabu.de/themen/meere/plastik/fishingforlitter,14.11.2015)[5] The Ocean Cleanup (www.theoceancleanup.com, 14.11.2015)[6] E. R. Zettler, T. J. Mincer, L. Amaral-Zettler, Life in the „Plastisphere“:
Microbial Communities on Plastic Marine Debris, Environmental Science Technology 47 (2013) 7137-7146[7] H. K. Imhof, N. P. Ivleva, J. Schmid, R. Niessner, C. Laforsch, Contamination of beach sediments of a subalpine lake with microplastic
particles, Current Biology 23 (2013) 867-868[8] M. Wagner, C. Scherer, D. Alvarez-Muñoz, N. Brennholt, X. Bourrain, S.
Buchinger, E. Fries, C. Grosbois, J. Klasmeier, T. Marti, S. Rodriguez-Mozaz, R. Urbatzka, A. D. Vethaak, M. Winther-Nielsen, G. Reifferscheid,
Microplastics in freshwater ecosystems: what we know and what weneed to know. Environmental Sciences Europe 26 (2014) 12[9] A. Lechner, H. Keckeis, F. Lumesberger-Loisl, B. Zens, R. Krusch,
M. Glas, M. Tritthart, E. Schludermann, The Danube so colourful: a
potpourri of plastic litter outnumbers fish larvae in Europe’s second
largest river, Environmental Pollution 188 (2014) 177- 181[10] E. Fries et al., Identification of polymer types and additives in marine
microplastic particles using pyrolysis-GC/MS and scanning electron
microscopy, Environmental Science: Processes Impacts 15 (2013)
1949-1956[11] J. Willmeyer, Analysis of marine plastic debris using thermodesorptionpyrolysis-gas chromatography/mass spectrometry (TD-Pyr-GC/MS), Bachelor-Arbeit, Institut für Umweltsystemforschung, Universität
Osnabrück, September 2012[12] J. Henning Dekiff, Occurrence and spatial distribution of microplastics
and organic additives in sediments from the Island Norderney, Master-Arbeit, Institut für Umweltsystemforschung, Universität Osnabrück,
November 2012[13] Marine Strategy Framework Directive, http://ec.europa.eu/environment/marine/eu-coast-and-marine-policy/marine-strategy-framework-directive/index_en.htm[14] E. Kleine-Benne, B. Rose, Versatile automated pyrolysis GC combining
a filament type pyrolyzer with a thermal desorption unit, GERSTELApplication Note 11/2011 (www.gerstel.de/pdf/p-gc-an-2011-04.
pdf)

7

Metabolomics (Part 2)

Automated Sample Preparation
Using the GERSTEL MPS WorkStation
Automated Lipid Fractionation Using Solid Phase Extraction
Metabolomics studies focus on the analysis of small molecules (MW<2000) in biological matrices,
processing relatively large sets of samples to allow differentiation between sample types. In orderto obtain statistically meaningful results, analytical variability should be much lower than biologicalvariability and automation of sample preparation can significantly contribute to improved repeatabilityof the total analytical procedure.
By Koen Sandra, Ruben t’Kindt, Christophe Devos, Bart Tienpont, Pat Sandra, Frank David
Research Institute for Chromatography, President Kennedypark 26, 8500 Kortrijk, BelgiumIn a typical metabolomics workflow, extraction of thesample is followed by fractionation or clean-up, and if
needed, derivatization, concentration, and finally GC or
LC separation and MS detection. In a series of articles,
we describe a number of automated methods that are currently applied in our laboratories. In the first article, automated ultrasonic assisted liquid extraction and filtration
using the GERSTEL MPS Workstation were discussed[1]. In this second article,
an automatic fractionation
Lipidomics
procedure based on solid
Lipidomics is the large-scale study ofphase extraction (SPE) ispathways and networks of cellular lipids indescribed. This method was
biological systems. The word „lipidome“
used in a lipidomics study,
is used to describe the complete lipid
profile within a cell, tissue or organism
focusing on the characterizaand is a subset of the „metabolome“
tion of plant material basedwhich also includes the three other major
on the relative composition
classes of biological molecules: proteins/of different classes of lipids,
amino-acids, sugars and nucleic acids.
including neutral lipids (triLipidomics is a relatively recent research
field that has been driven by rapid
glycerides, sterols), free fatty
advances in mass spectrometry (MS) andacids and polar lipids. Dueother analytical technologies, as well as
to the fact that these classes
computational methods, coupled withare present in the plant matethe recognition of the role of lipids inrial at substantially different
many metabolic diseases such as obesity,
atherosclerosis, stroke, hypertension andconcentration levels, it wasdiabetes. This rapidly expanding fieldobserved that fractionation
complements the huge progress madeand selective enrichment ofin genomics and proteomics, all of which
lipid classes prior to LC-MS
constitute the family of systems biology.
analysis resulted in a much
Source: Wikipedia
better coverage of lipids [2].
After liquid-liquid extraction, based on the Folch method [3], a concentrated lipid fraction was obtained. Next,
fractionation was performed in a “normal phase LC”
mode on an aminopropyl SPE cartridge. Three fractionsof increasing polarity were obtained and the extracts wereconcentrated using a Multi-Position Evaporation Station(mVAP) installed on the MPS Workstation. Finally, theconcentrated extracts were analyzed by LC-QTOF.

8

Experimental
Automated Extraction.
A one gram sample of plant material was extractedwith 6 mL chloroform:methanol (2:1). Next, 4 mL water was added and 1.5 mL from the bottom chloroform
layer was filtered into a high recovery vial. The solvent
was evaporated in an mVAP station. Extraction, filtration and concentration was performed on a separate
MPS WorkStation unit.
Fractionation by Solid Phase extraction.
Automated SPE and concentration were performed
using a MPS Dual Head WorkStation configured as
illustrated in Figure 1 and listed in Table 1.
The extracts obtained from the extraction and filtration steps were reconstituted in 300 μL chloroform.
These extracts were fractionated using the SPE protocol shown in Figure 2. Basically three fractions of increasing polarity were obtained, containing neutral lipids (NLs), free fatty acids (FAs) and polar lipids (PLs),
Table 1: MPS Dual Head WorkStation configured for automatedSPE and analyte concentration
MPS Module

Description

Left Arm
Right Arm
Tray and Holder
Tray and Holder
Wash Station
Stacked Tray

500 µL syringe
2.5 mL syringe
10 mL headspace vials for SPE fractions
SPE cartridges
Needle wash
1.5 mL high recovery vials for filteredextracts (samples)
SPE Module
Performs SPE using replaceable, standard
dimension packed bed cartridges
mVAP
Vacuum assisted evaporation of extracts
and SPE fractions
Solvent Filling Station SPE Solvents – Hexane, 2:1 Chloroform/
IPA, Diethyl ether (2% acetic acid), andMeOH

GERSTEL Solutions worldwide – No. 16

Image: RIC

Figure 1. MPS Dual Head WorkStation
configured for automated SPE andanalyte concentration.

respectively. These three fractions (collected in 10 mL
vials) were concentrated to dryness in the mVAP station
and reconstituted in chloroform:isopropanol for LCMS analysis. Solvent amounts were optimized according to the concentration of the lipids in the extracts [2].
LC-MS
An Agilent Technologies 1290 Series UHPLC System
coupled to a 6540 Q-TOF LC/MS was used for the
analysis of the extracts (Agilent Technologies, Waldbronn, Germany). A reversed-phase separation was
performed on a C18 column using 20 mM ammonium
formate in water and methanol as the mobile phase
constituents [4]. In total, 4 LC-MS methods were

Results andDiscussion

Suggested reading

Development and validation ofa robust automated analysis ofplasma phospholipid fatty acids formetabolic phenotyping of large
epidemiological studies.
Laura Yun Wang, Keith Summerhill,
Carmen Rodriguez-Canas, Ian
Mather, Pinal Patel, Michael Eiden,
Stephen Young, Nita G Forouhi andAlbert Koulman, Genome Medicine (2013)
5:39, DOI: 10.1186/gm443, http://
genomemedicine.com/content/5/4/39

For a plant lipid study, 84
samples were prepared using
the automated SPE method
described above. Samples
from 22 individual plants,
belonging to 3 main types,
were each prepared in triplicate. In addition, 18 quality
control (QC) samples wereanalyzed to assess the reproducibility of the sample
preparation and LC-MS protocol. Photos of reconstituted SPE fractions of three plant samples (each belonging to a different main class) are shown in Figure 3.
Typical LC-MS chromatograms are shown in Figure 4. The upper trace shows the analysis of fraction
1 (neutral lipids) in ESI POS mode. Monoglycerides(MGs), diglycerides (DGs), triglycerides (TGs) andplant sterols are detected. Trace B shows the analysis

Image: RIC

Figure 2. Automated SPE procedureused, applying slightly different gradients and different
MS conditions. Fraction 1 was analyzed using positive electrospray ionization (ESI POS), fraction 2 wasanalyzed in negative ESI mode (ESI NEG), and fraction 3 was analyzed both in ESI POS and ESI NEG
modes.

Figure 3. Reconstituted plant extracts after SPE fractionation and mVAP concentration. A, B and C correspond to three different types of plants. F1: Neutral
Lipids (NL); F2: Free Fatty Acids (FF); F3: Polar Lipids (PLs).

GERSTEL Solutions worldwide – No. 16

9Image: RIC
Figure 4. Total ion chromatograms of LC-QTOF analyses of the SPE fractions. A: fraction 1 in ESI POS mode, B: fraction 2 in ESI NEG mode, C: fraction 3
in ESI POS mode, D: fraction 3 in ESI NEG modeof the long chain free fatty acids (LCFAs) present infraction 2 using ESI NEG mode. Traces C and D show
the detection of phospholipids (PLs), sphingolipids andother polar lipids in ESI POS and ESI NEG modes respectively.
To evaluate the precision, a number of identified
compounds were selected, and the area RSD% of eachcalculated. The results are presented in Table 3. It should
be noted that for large-scale lipidomics studies, the cutoff
for area RSD values is typically 30 % [5]. As can be seenfrom Table 3, the results obtained for the 18 QC samples
gave an area RSD of less than 20 % in most cases.

Conclusions
The GERSTEL MPS dual head WorkStation is particularly useful for the automation of sample preparation inmetabolomics studies. A lipid class fractionation method
based on solid phase extraction was fully automated on a
dedicated platform, including concentration of the SPE
fractions by solvent evaporation. The LC-QTOF analysis
results for the fractions showed excellent repeatability. In
an upcoming article, the automation of a derivatization
protocol combined with GC/MS analysis applied in metabolomics will be described.

Table 3. Precision of lipidomics methods including automated sample preparation.

FractionF1 (+)

F2 (-)

F3 (+)

F3 (-)10

Lipid
MG (18:3)
Solanesol
LANE (18:3)
SOLE (18:3)
LCFA-OH (18:3)
LCFA (18:3)
LCFA (16:0)
MGMG (18:3)
LysoPC (18:1)
GlcCer (d18:2/16:0)
PC (36:2)
MGDG (36:0)
MGMG(18:3)
LysoPC(18:1)
GlcCer(d18:2/16:0)
PC(36:2)
MGDG(36:0)

Mass
369.2879
647.6005
703.6267
907.8145
294.2210
278.2259
256.2414
531.3407
521.3481
697.5493
785.5935
803.6486
560.3197
567.3550
713.5471
831.5980
832.6212tR [min]
6.389
29.09738.74944.9187,540
14.49717.245
8.137
9.783
25.47030.79434.5408.186
9.868
24.49430.74532.410% RSD Area
9.6
8.6
5.5
7.7
11.7
5.4
6.2
22.1
21.6
23.4
18.7
8.2
10.1
19.4
15.2
10.3
5.8

References[1] Koen Sandra, Frank David, Christophe Devos,
Bart Tienpont, and Pat Sandra, Automated Sample
Preparation for Metabolomics Studies Using the
GERSTEL MPS Dual Head WorkStation, Part 1:
Automated Ultrasonic Assisted Liquid Extraction
and Filtration, GERSTEL Application Note 8/2014[2] Melissa N. Dunkle, Yuta Yoshimura, Ruben t’Kindt,
Alexia Ortiz, Eri Masugi, Kazuhisa Mitsui, FrankDavid, Pat Sandra, and Koen Sandra, Lipidomics
of tobacco leaf and cigarette smoke, Journal of
Chromatography A 1439 (2016) 54–64[3] J. Folch, M. Lees, G.H. Sloane Stanley, J. Biol.
Chem. 226 (1957) 497-509[4] K. Sandra, A.D.S. Pereira, G. Vanhoenacker, F.
David, P. Sandra, J. Chromatography A 1217
(2010) 4087-4099[5] J. Boelaert, R. t‘Kindt, E. Schepers, L. Jorge, G.
Glorieux, N. Neirynck, F. Lynen, P. Sandra, R.
Vanholder, K. Sandra, Metabolomics 10 (2014)425-442GERSTEL Solutions worldwide – No. 16

Automation technology

Looking for Automation?
What should you look for when buying a new autosampler for GC/MS and LC/MS
Laboratories carefully analyze their current requirements for productivity and efficiency before
investing in autosamplers for GC/MS and LC/MS. It also makes sense to look at automation
potential, specifically automated sample preparation.
By Ralf BremerE

analyses. To meet all demands and keep the customer
satisfied, a good start is to automate manually performed routine sample preparation tasks. Typical examples
are generating standards or dilution series - or adding
an internal standard or derivatization reagent. But thepossibilities are, if not endless, more extensive thanmost people would think, provided you have the rightautomation platform. So when you are trying to decide
which autosampler is best for your needs, it is a goodidea to carefully determine which manual steps in yourImage: istock / Devrimbvery GC/MS and LC/MS laboratory today faces
ever-increasing productivity and efficiency demands.
Typically the number of samples keeps increasing, but
staff is not added or is even reduced. To make matters even more challenging, there is constant pressure
to reduce cost, save energy and to eliminate or reduce
the amount of potentially toxic solvents used. Also, it
is necessary to have maximum flexibility as new sample types require new methods for sample preparation
and analysis, but with the same turnaround as standard

11

workflow can be automated and make sure you find an
autosampler that fits these needs. There are significant
differences between automation platforms – especiallyin the sophistication of the software used to automate
more advanced sample preparation steps, so it is criticalthat these features are thoroughly evaluated.

Basic autosampler functionality is a good
indicator of success
A modern autosampler based on an X-Y-Z robot, suchas the GERSTEL MultiPurpose Sampler (MPS), canperform almost unlimited tasks since it moves unrestricted in three dimensions and can access a large numberof sample positions. Standard tasks include sample introduction to GC/MS or LC/MS or
simple sample preparation steps
like adding an internal standard.
This is a good starting point,
but one needs to look deeper.
Maybe you need a sampler
to perform dilution series orgenerate a series of calibration standards. All this mustbe accompanied by enoughsyringe- or valve rinsing pos-

Image: GERSTEL / Wolfram Schroll

GC/MS system from Agilent Technologies Inc. equipped with a GERSTEL MPS roboticpro for automatedsample preparation. The MPS is
configured with Dynamic Headspace(DHS) option. The standard DHS
system uses 20 mL vials – a version
that uses 1 Liter sample containers(DHS Large) is also available.

sibilities to eliminate sample-to-sample carryover andcross contamination.

Advanced functionality on demand
If more advanced sample preparation tasks need to be
performed at a later time, can these be added to the system in a modular fashion? Which options and accessories are typically added? Examples include filtration
or solid phase extraction (SPE), liquid-liquid extraction(LLE), centrifugation, solvent evaporation, solid phasemicro-extraction (SPME), stir bar sorptive extraction(SBSE) as well as static and dynamic headspace (HS/DHS). A fully loaded autosampler is rarely needed, but
it is very useful to be able to add these capabilities on
demand with little effort or additional expense.
On the sample storage side, a wide range of sample
vessels should be accommodated. These should include
deep well plates, and standard vials and even customized
trays for any container you might need in your method.
The possibility of storing samples cold in order to eliminate analyte degradation and preserve sample or reagent
integrity - or of heating and agitating after a reagent has
been added - should be available as options.
The Dual Head version of the MPS can performdifferent tasks simultaneously for improved productivity and flexibility; this includes handling vastly different
liquid volumes using two different syringe sizes. Having
both of these mounted in the Dual Head MPS offers ahigher degree of flexibility and productivity since you do
not have to manually change the syringe or wait for thesyringe to be changed (available with the MPS roboticpro) during the sample preparation method.

The little differences that mean a lot
Can the autosampler be fitted with a separation technique such as a centrifuge? Can it do vortexing and solvent evaporation? Can liquids be added under highly
controlled conditions and the amount determined using
a balance? The availability of any of these capabilities
can be the deciding factor in finding the right solution
for your needs when automating manual sample preparation processes and making them fully traceable on a
24/7 basis.

Application and integration requirements
Is the autosampler needed for sample introduction directly into the GC/MS or LC/MS system? If so, wouldn’t it
be helpful to perform sample preparation and analysis inparallel? This would ensure that samples are always prepared immediately before being analyzed and could maximize system utilization. Or will the system mainly be
used as a separate workstation to generate standards anddilution series for the analysis instrument(s)? The clearer
the definition, the easier it is to select the right autosampler, both for current and for future requirements.
The main sources for information and comparisons are
Laboratory Magazines and their websites. Laboratory
Instrumentation Exhibitions such as PittCon, ASMS

12GERSTEL Solutions worldwide – No. 16

Image: GERSTEL / Wolfram Schroll

A modern GC/MS Laboratory. The analysis systems are equipped with high performance autosamplers that can automate all steps in sample preparation and introduction. The high degree of automation helps ensure productivity and throughput while offering enough flexibility to easily adapt to new sample types, analysis
methods and performance requirements.

and Analytica in Europe can also serve to enable comparisons in a short time span. Obviously vendor websites
offer detailed information, typically with a lot of application examples. GERSTEL is among the leading providers of intelligently automated solutions for GC/MS and
LC/MS. If you are considering automating your sample

preparation and -introduction, please contact your local
GERSTEL representative. We have many years of experience applying our automation solutions to real world
samples and applications. If you let us know what you
want to achieve, we will listen carefully before proposing
a solution that truly fits your needs.

What you should consider when you choose your next autosampler
1. Keep it simple. It may sound nice to have an
autosampler that can do everything, but it
can add unnecessary cost and operational
complexity.
2. The software package is your everyday
interaction with the instrument. Make sure it
is as easy as possible to operate and that it
adapts directly to the instrument configuration
to eliminate unnecessary complexity, it shouldbe “plug and play”. Also, you should be able
to change and adapt methods and sample
preparation processes without the need forprogramming steps and external support.
3. Plan your purchase and your laboratory
automation with your mid-to-long term strategies
and goals in mind. Limit your investment to
fit your current needs, but make sure thattechnologies can be added at a later time as
your needs change without having to purchasecompletely new systems and rendering the

GERSTEL Solutions worldwide – No. 16

initial investment obsolete. Even if the plan is
to automate liquid-liquid extractions, it can bebeneficial to be able to update the system toperform evaporation, filtration, SPE or evenheadspace.
4. Make sure you get good support. Laboratory
autosamplers are high-tech products and theyoften need individual implementation dependingon the sample types and performancerequirements. Make sure the supplier has theexperience and resources to provide efficienttechnical and application support without delay.
5. Consider existing systems in the laboratory.
New autosamplers can upgrade existing GC/
MS or LC/MS systems to a higher performancelevel by removing interfering matrix compounds
or concentrating analytes. Relying on existing
systems in the laboratory could provide
significant savings.

13

Images: GERSTEL / Wolfram Schroll

Automated Liquid-Liquid Extraction (LLE)

Speeding up the workflow …
In addition to SPE workflows, the GERSTEL MultiPurpose Sampler (MPS) can perform fully automatedliquid-liquid extraction. Several functionalities can be added as modules.
By Oliver LerchA

n important stepping stone on the path to improved
productivity is the automation of manually performed
sample preparation steps. Whether these can be transferred to an automated sampler system of course depends
on whether the sampler has the individual capabilities
needed to perform each step in the process. Multiple application examples have been reported
over the years using the GERSTEL
Suggested reading
SPE system based on the MultiPurDetermination of THC
pose Sampler (MPS) [1, 2].
and its metabolites
11-hydroxy-THC (THCOH)
Recently, a similar effort has been
and 11-nor-9-carboxy-THC
under
way to automate several aspects(THC-COOH) in blood serumofandcomplete workflows for liquidK. Purschke, S. Heinl, O.Lerch, F.
Erdmann, F. Veit, Anal Bioanal Chem,
liquid extractions (LLE).
DOI 10.1007/s00216-016-9537-5
Application examples include deLink: http://link.springer.com/
terminationof Tetrahydrocannabinol
article/10.1007/s00216-016-9537-5(THC), the active compound in cannabis, and the cannabinoids cannabinol (CBN) and Cannabidiol (CBD) all in human hair (A scientific publication
has been accepted by the Journal of analytical Toxicology).
In addition, an article on the determination of THC and its metabolites 11-hydroxy-THC (THCOH)
and 11-nor-9-carboxy-THC (THCCOOH) in blood serum has been
published in the Journal of Analytical and Bioanalytical Chemistry [3].
The GERSTEL GC/MS-solutions
configured for those applications arebeing used successfully by Forensic
GERSTEL MultiPurpose Sampler (MPS)m
Toxicology Institutes. In addition toequipped with centrifuge, VAP and
Quick Mix.
these more special analyses, a muchwider array of applications require liquid-liquid extraction.
All steps required in such a process can be automated using the GERSTEL MPS. Key elements in such systems

14

are the CF 200 centrifuge, the MultiPosition Evaporation
Station (mVAP) and quick Mix. The only step that must be
performed manually is the addition of the liquid or solid
sample into a vial and placing the vial in the MPS sample
tray. All other steps are performed automatically. The
analytical method and sample sequence is simply set up
with a few mouse-clicks using GERSTEL MAESTRO
software.
The MPS adds internal standards to the sample followed by extraction buffer and extraction solvent. The
extraction is performed in a few minutes while the MPS
agitates the sample vigorously in the quickMix ensuring
thorough mixing. The phases can then be separated efficiently using the CF 200 centrifuge, or alternatively, amore powerful Sigma® centrifuge. The MPS aspirates theextract and transfers it to a clean vial. As needed an additional extraction step is performed using a new volume
of clean solvent. Depending on the analytical workflow requirements, the MPS can inject an aliquot of the resulting
extract into the analysis instrument or evaporate it to dryness in the mVAP. If evaporated to dryness, the residue canthen be taken up in an HPLC compatible solvent with theoption of adding a derivatization reagent. The steps to include in the final workflow are totally up to the user. These
examples show how the MPS can be used as a highly flexible and rugged tool for automated liquid-liquid extraction
processes. An additional application example based on veterinary samples can be found online [4].
References[1] www.gerstel.com/en/apps-spe.htm[2] www.gerstel.com/en/Solutions-Articles-SPE.htm[3] K. Purschke, S. Heinl, O.Lerch, F. Erdmann & F. Veit, Anal Bioanal Chem, DOI 10.1007/s00216-016-9537-5 Link: http://
link.springer.com/article/10.1007/s00216-016-9537-5[4] www.gerstel.com/pdf/p-lc-an-2014-07.pdf

GERSTEL Solutions worldwide – No. 16

Forensic science and toxicology

Automated determination of THC,
CBN and CBD in human hair
In a joint research project with the Institute of Forensic Medicine at the University of Giessen,
Germany, GERSTEL has successfully automated a validated manual analysis method for determining
Δ9-tetrahydrocannabinol (THC) and the cannabinoids cannabinol (CBN) and cannabidiol (CBD) in
human hair.
By Oliver Lerchrom a forensic toxicology point of view, human hairsamples are extremely well suited for determining aperson’s consumption pattern of medication or drugs ofabuse over a period of time. A human hair grows between
0.25 and 0.4 millimeters per day, in other words between
7.5 and 12 millimeters per month. Once consumed, drugs,
active ingredients from medications as well as the metabolites formed, are distributed throughout the body andalso incorporated into human hair as it grows. In cases of
one-time or short-term drug use, the position of thesesubstances within each hair stays fixed as the hair grows.
In other words, prior drug use is no longer detectable after
the hair has fallen out or you’ve gone for a haircut and thehairdresser has thrown away the evidence. Hair analysis
can be used to detect drug abuse and to determine, whichdrugs have been consumed over which time period. By
the same token, hair analysis can be used to confirm drug
abstinence.

Hair today, gone tomorrow: How todetermine cannabis consumption over time
Detecting prior cannabis consumption through hairanalysis is a complex and labor-intensive process. The
residual substances stored in hair must first be released
from the matrix and converted into a form that is suitable for GC/MS analysis. At the Institute of Forensic
Medicine at the University of Giessen, the steps required
to prepare human hair samples are performed manually.
Δ9-tetrahydrocannabinol (THC), the active compound incannabis, and the cannabinoids cannabinol (CBN) andcannabidiol (CBD), are then determined by GC/MS.
GERSTEL’s goal in working with the Institute of Forensic Medicine was to assess the potential for automationof the analysis processes used and to develop a solution
based on a GC/MS system with integrated automatedsample preparation and sample introduction.

The manual procedure is the starting point
Determining whether an existing manual method ofanalysis is suitable for automation requires thorough evaluation of the entire process. All aspects of the method
need to be examined such as sample throughput required,reagent type, volumes of liquids used, and whether heatGERSTEL Solutions worldwide – No. 16

ing, mixing or filtration is required, to name just a few.
The Forensic Institute’s manual procedure to determine
Δ9-tetrahydrocannabinol (THC) and the cannabinoids
cannabinol (CBN) and cannabidiol (CBD) in hair was:
A 100 mg hair sample is washed with hexane and acetone
and then finely ground. The hair is then dissolved in a
one molar sodium hydroxide solution (NaOH) at 80 °C
for 25 minutes. The target analytes are extracted from thehair matrix in two sequential liquid/liquid extractions using a 9/1 (v/v) mixture of hexane and ethyl acetate. The
resulting extracts are combined and evaporated
to dryness and aderivatization
reagent consisting of BSTFA
and TMCS
is added to
the residue
at a ratio of
99/1(v/v);
derivatizationis performed at
110 °C over a period of 20 minutes.
The resulting solution
is again evaporated, the residue taken up in ethyl acetate and an aliquot injected intoa GC/MS system for analysis in single ion monitoring(SIM) mode.

copyright: istockphoto / Gishal

F

Automated hair analysis
The efforts to fully automate the manual method used
for determining THC, CBN and
CBD in hair were successful. The
Suggested reading
primary focus of the project was
Determination of THC andautomating the sample preparaits metabolites 11-hydroxytion. For this task, the dual-head
THC (THCOH) and 11-norversion of the GERSTEL Mul9-carboxy-THC (THC-COOH) inblood serum
tiPurpose Sampler (MPS) was
K. Purschke, S. Heinl, O.Lerch, F.
selected. The Dual Head version
Erdmann, F. Veit, Anal Bioanal Chem,
allows two different syringes to
DOI 10.1007/s00216-016-9537-5,
http://link.springer.com/article/
be used simultaneously, allow10.1007/s00216-016-9537-5
ing the MPS to handle different

15

solvents, different volumes and make injections into an
analytical system quickly and efficiently by eliminating theneed to stop the sample preparation process in order tochange syringes. The MPS can be configured with a wide
range of optional modules to meet almost any need, including a solvent evaporation module (mVAP) for sample
concentration, a centrifuge, and a vortex shaker to name afew. The automated procedure involves placing a vial containing a ground hair sample and internal standard in the
MPS sample tray, after which all subsequent steps in themethod are performed by the MultiPurpose Sampler under MAESTRO software control.
The following steps were performed:• A 100 mg sample of ground hair (plus ISTD) was
placed in 1 molar NaOH and incubated at 85 ˚C for 13
minutes until dissolved• Two extractions with hexane/ethyl acetate (9/1, v/v)
were performed for 4 minutes each at 200 rpm in the
GERSTEL quickMIX• Phase separation by centrifugation at 4500 rpm
for 3 minutes• Extracts evaporated to dryness at 65 °C (mVAP)• Introduction of MSTFA / ethyl acetate(GERSTEL quickMIX)• Injection of 2 μL (inlet derivatization)• GC separation was performed using a DB-5MS
30 m x 0.25 mm x 0.25 μm capillary column (Agilent Technologies) with mass spectrometric detection(MSD) in single ion mode (SIM).

Results

Sample vial after hair digestion, extraction andcentrifugation. A clear phase separation between the upper organic extract phase and lower
aqueous phase (dissolved hair) is achieved.

Conclusion and outlook
In close cooperation with the Institute of Forensic
Medicine at the University Medical Center, Giessen,
GERSTEL successfully automated the manual method
previously used at the institute for determination of THC,
CBN and CBD in human hair. The required 0.02 ng/mg
limit of detection for THC was achieved. As planned,
the manual sample preparation steps were automated using a GERSTEL MultiPurpose Sampler (MPS) under
MAESTRO software control. The PrepAhead feature
optimizes throughput by preparing the next sample inparallel during the ongoing GC/MS analysis. This ensures that each sample is treated in the same manner andinjected immediately after it has been prepared. GERSTEL’s quickMIX, centrifuge and mVAP modules wereable to reproduce the manual steps previously used in themethod, from mixing and extraction to evaporative concentration of the extracts. It was found that derivatizationof the analytes was best performed in the hot GC inlet. In
addition to the determination of THC, CBN and CBDin human hair, the steps automated in this method can beapplied to a variety of other manual liquid/liquid extractions and sample preparation methods.

Any method must prove its worth in practical use. The
automated method for determination of THC, CBN and
CBD in hair using the MPS to prepare and inject the samples was validated in accordance with GTThe author wishes to thank Sonja
FCh guidelines. The
Heinl, Freidoon Erdmann andlimit of determination
Florian Veit from the University
for THC was 0.01 ng/
Medical Center, Giessen, Germany
for the excellent cooperation.
mg; the extraction efficiency (at 0.02 ng/mg) was 102 %and the precision (at 0.02 ng/mg) was
4.2 %.

16

Copyright: GERSTELUsing the GERSTEL
method, the extraction of THC, CBN
and CBD from hairis fully automatedand is acceleratedusing the GERSTEL
quickMIX module
mounted on the
MPS.

GERSTEL Solutions worldwide – No. 16

Image: Istockphoto / Yarygin

GC/MS system configured for liquid-liquid
extraction. Shaker (left),
evaporation station(center) and centrifuge(right).

Forensic Toxicology, Pharmaceutical Research and Doping Analysis

What a drop of blood reveals
In blood analysis, precision, sensitivity and the required sample amount are important factors – alongwith the analysis time. In all these areas, Dried Blood Spot (DBS) sampling and analysis is a convincing
alternative – especially when automated with the GERSTEL MultiPurpose Sampler (MPS).
By Oliver Lerch

card is loaded into the desorptionince the 1960s, Dried
DBS Card
SPExosinterface and clamped into poBlood Spot (DBS) samCartridge
sition. A desorption eluent thenpling has been used. Iniflows through a defined area oftially, especially neonatal
Waste
the blood spot desorbing the anascreening for metabolic dislytes based on the patented Floworders was performed based
Through Desorption techniqueon the DBS technique.
(FTD TM); an internal standard
In recent years, especiallysince more powerful GC/
can be added to the desorption
LC(-MS/MS)MS and LC/MS systemeluent for quality purposes if
diagram of DBS flow-through desorption (FTDTM) and SPE cleanbecame generally available, Schematic
required.
up. FTD is patented by, and is a registered Trade Mark of, Spark Holland B.V.
DBS has become useful in
An eluate clean-up step can
pharmaceutical research [1],further be performed based on an
forensic toxicology and doping analysis [2-4] as well as on-line SPE module which can be integrated into the oveveterinary analysis [5].
rall analysis system. The online SPE system (GERSTELJust a few drops of blood taken from a fingertip are SPExos) is based on replaceable SPE cartridges, ensuring
sufficient to perform DBS analysis. The drops are placed minimal sample to sample carry over while efficiently
onto small circular fields on special cards used for DBS transferring the analytes to the LC-MS/MS system withwork. As soon as the drops have dried, the cards are used best possible recovery for best possible LODs. Finally,
to store and transport the samples, which are extracted di- the card is released and the associated tubing thoroughly
rectly from the card using dedicated sampling equipment. rinsed with solvent. The card is again photographed
A DBS sample typically contains between 15 and 30 to enable full documentation of the sample area,
μLs of blood evenly distributed across the spot. This me- which has been desorbed.
ans that a representative sample – and a defined amountConclusion: The fully automatedof blood – can be taken by simply punching out a small DBSA system enables fast and reliable
area of the blood spot. Traditionally, a small, well defi- determination of analyte concenned disc of a few millimeters across has been punched out trations with excellent
from the blood spot and transferred to a vial or micro-titer LODs.
plate in which it was extracted using a suitable solvent.
The resulting extract was centrifuged and the supernatantcleaned or analyzed directly following solvent exchange.
References
Most often, LC-MS/MS or GC-MS/MS are the analysis[1] Q. C. Ji, G. Liu, C. J. D‘Arienzo, T. V.
techniques used. The described procedure is used for maOlah, M.E. Arnold, “What is next fornual sample preparation based on DBS cards.
dried blood spots?”, Bioanalysis 4

Images: GERSTELSMPS-based GERSTEL DBSA Autosampler (to the left)*For research use only. Not for use in diagnostic procedures.

Automation improves productivity
In order to improve throughput and simplify the routine
analysis workflow, the DBS technique must be properly
automated. In cooperation with Spark Holland B.V.,
GERSTEL has developed an integrated system based on
the Spark DBS system, with fully automated samplingfrom up to 240 DBS cards. Automation is performed using
the GERSTEL MultiPurpose Sampler (MPS) underM A ESTRO sof t wa re cont rol. T he system canoperate as stand-alone workstation preparing samples for LC/MS analysis - or integrated with the
LC-MS/MS system. Slightly simplified, the DBSM P S -L C-M S / M S Sy s tem* work s a s fol low s:
The MPS transports a DBS card to a camera. An image
recognition software evaluates the dried blood spot. The
GERSTEL Solutions worldwide – No. 16(2012) 2059
with SPExos-Module (right hand side) for direct connection[2] C. P. Stove, A. S. Ingels, P. M. M. De
to the LC-MS/MS system (not shown).
Kesel, W. E. Lambert, “Dried Blood
Spots in Toxicology: from the Cradle to the Grave?”, Critical Reviewsin Toxicology 42 (2012) 230[3] L. Tretzel, A. Thomas, T. Piper, M. Hedeland, H. Geyer, W. Schänzer,
M. Thevis, “Fully automated determination of nicotine and its major
metabolites in whole blood by means of a DBS online-SPE LC-HRMS/MS approach for sports drug testing”, Journal of Pharmaceuticaland Biomedical Analysis 123 (2016) 132–140[4] L. Tretzel, C. Görgens, H. Geyer, A. Thomas, J. Dib, S. Guddat, V. Pop,W. Schänzer, M. Thevis, “Analyses of Meldonium (Mildronate) from
Blood, Dried Blood Spots (DBS), and Urine Suggest Drug Incorporation into Erythocytes”, International Journal of Sports Medicine · DOI
10.1055/s-0036, https://www.thieme-connect.com/products/
ejournals/pdf/10.1055/s-0036-1582317.pdf[5] F. D. Foster, J. R. Stuff, E. A. Pfannkoch “Automated Desorption, SPE
Extraction, and LC-MS/MS Analysis of Dried Blood Spots”, GERSTELAppNote 4/201517

Imaget: istock / Tuned_In

Flavor, Fragrance, and Odor Analysis

A new Twist:
Free acids and phenols
Sensitive SBSE determination of free acids and phenols - along with the usual suspects
By Ray Marsili and Charles Laskonis, Rockford University, Rockford, Illinois, USA.

S

Image: GERSTEL / Malte Reimold

tir Bar Sorptive Extraction (SBSE) and Headspace ticle. Versatile application of Twister technology combined
Sorptive Extraction (HSSE) have regularly been applied with Thermal desorption – GC/MS and peak deconvolusuccessfully to the analysis
tion are adding up to a sigof odor-active chemicals in anificant analytical tool-kit
GERSTEL-TwicesterDwide variety of sample matrito assist the flavor chemces at concentrations as low as
ist in off-flavor and malultra-trace levels. The addition
odor elucidation, detectingCof the Ethylene Glycol-Siliboth non-polar and polarcone (EG-Silicone) Twister®
analytes spanning a wideAB
has significantly enhanced therange of volatilities andusefulness of these techniques
concentrations.
by enabling the efficient exExamples presented intraction of polar hydrogen
this article include the debond donors like phenols andtermination of off odors incarboxylic acids – importantBeer, Pretzels, and Casein,
odor and flavor compounds.
a widely used food ingreVarious SBSE and HSSE
dient. Last but not least,
extraction techniques usaxillary off odors were
1: Schematic diagram of the multi stir bar extraction process using
ing different combinations Figure
determined in well-worn
Twicester® (A) Magnetic positioning of up to three Twisters using Twicesof PDMS and EG-Silicone ter Showing 1 Twister in HS & 1 stirring (B)mSBSE using two Twisters
T-shirts to determine thein liquid (C)Transfer of Twisters to TDU Tube (D) SimultaneTwisters were used to analyze submergedodor-reducing impact ofous thermal desorption of the Twisters, cryofocusing in the CIS and GC/
samples discussed in this ar- MS analysis.
antibacterial fabrics.

18

GERSTEL Solutions worldwide – No. 16

A simple, solvent free, quantitative, and sensitive
analytical method for studying off-flavor development inbeer based on SBSE using the GERSTEL PDMS Twister has previously been published [1]. Beer contains dozens of odor active chemicals in concentrations in the parts
per billion range. Developing an analytical technique tocover such a wide range of volatiles and concentrationlevels is challenging. In the work presented here, recently
developed SBSE techniques were combined with gas
chromatography-time of flight mass spectrometry (GCTOFMS) incorporating peak deconvolution software.

Beer off-flavor chemicals
The aim was to determine which approach would be
most appropriate for detecting low levels of potential offflavor chemicals in aged beer. Four Twister methods wereused to analyze Blue Moon beer, a Belgian-style wheat
ale. Ten milliliters of beer were extracted in all cases:(a) One PDMS Twister (1 cm x 0.5 mm) submerged in
the beer inside a sealed 20 mL vial, stirring at 900 rpm
for 2 hours;(b) Same as (a) with a second PDMS Twister submergedin the beer, attached to the inside of the vial using a
GERSTEL Twicester® magnet clip as seen in Figure 1;(c) Sequential SBSE with two PDMS Twisters (1 cm x
0.5 mm) stirred in sample for 1hr [2], followed by salt
addition (20%) and stirring for an additional hour;and finally(d) Extracting the beer sample with one immersed
PDMS Twister used for stirring and one EG-Silicone
Twister attached to the inside of the vial submerged in
the beer using Twicester®.
Our results show that using the combination of the
PDMS and EG-Silicone Twisters enabled significantly
more sensitive determination of polar compounds including carboxylic acids compared with the other methods. In
figure 2, peak areas for fourteen odor-active compounds
are shown (normalized to PDMS + EG-Silicone results)
for the four SBSE methods used on the same Blue Moon
beer. For all but one of the compounds, (2-methyl-2-pentenoic acid), the PDMS + EG-Silicone method provided
the highest recovery. Sequential SBSE was the second
most favorable. The higher recoveries for carboxylic acids
with the PDMS + EG-Silicone method make the Twister
combination method an excellent choice for the determination of this important difficult-to-detect class of compounds. The compounds in question are: 4-vinyl guaiacol

Instrumentation

GC parameters
Column: DB-5MS (30 m x 0.25 mm x 0.25 mm).
Temperature program: 40 °C (3 min), 10 °C/min to 270 °C (10 min).
Carrier gas flow: 1.0 mL/min, splitless.
The same GC conditions were used for DHS and SPME.
The same column type and GC parameters were used on both
the Agilent and Leco systems.
Thermal desorption parameters
GERSTEL CIS 4: PTV Solvent Vent mode at a flow of 50 mL/
min. Initial temperature -100 °C (0.50 min) ramped to 280 °C(3.0 min). GERSTEL TDU: Initial temperature 30 °C (0.40 min)
60 °C/min to 280 °C (4.00 min hold time) when only PDMS
Twisters were used. A final temperature of 220 °C (4.0 min
hold time) was set when EG-Silicone Twisters were used.
TDU transfer line temperature: 300 °C.
Materials
GERSTEL Twisters used were PDMS 1cm x 0.5 mm; PDMS 2
cm x 0.5 mm; and EG-Silicone Twister. A GERSTEL Twicester®
magnetic clip was used to hold multiple Twisters inside thesample vial.

GERSTEL Solutions worldwide – No. 16

Image: Dr. Ray Marsili

The thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) analysis was performed using a GERSTEL
Thermal Desorption Unit (TDU) combined with a MultiPurpose
Sampler (MPS) and a GERSTEL Cooled Injection System (CIS
4) programmed temperature vaporization (PTV) type inlet.
Two GC-MS systems were used: an Agilent 7890A GC with an
Agilent 5973B MSD and a GC-TOF/MS system.

Figure 2: Comparison of four SBSE extraction techniques for odor-active chemicals in beer
(normalized to PDMS + EG-Silicone peak areas).

(clove flavor); linalool (floral); phenylethyl alcohol (rose);alpha-terpineol (pine, woody); 2-phenylethyl acetate (floral, honey); o-thymol (woody, camphor); and 2-phenylethyl esters of hexanoic, octanoic, and decanoic acids.

Axillary malodors in clothing fabrics
An understanding of human body odor chemicals may
be desirable for many reasons. For example, knowledgeof the composition of VOC metabolite excretions may
be a useful health-related diagnostic tool. Our studies
were undertaken to determine the ability of new fabrics
to minimize axillary malodors.

19

Image: Dr. Ray Marsili

2
3

9

Results and discussion
Several volatile acids were de6
14tected at low ppb (mg/L) levels from the sweat residue onworn T-shirts. These included
acetic acid, propanoic acid,isobutanoic acid, 3-methyl buFigure 3: Chromatogram of cotton shirt worn during exercise and analyzed by an HSSE dual Twister
methodtanoic acid, 2-methyl butanoic(1 PDMS + 1 EG-Silicone). Masses plotted for 60, 74 and 88 amu. Peak identities are: (1) isobutanoic
acid, pentanoic acid, hexanoicacid; (2) 3-methyl butanoic acid; (3) 2-methyl butanoic acid; (4) pentanoic acid; (5) hexanoic acid; (6)heptanoic acid;acid,
3-methyl-2-hexenoic(7) 2-ethyl hexanoic acid; (8) octanoic acid; (9) nonanoic acid. None of these axillary malodor chemiacid,octanoic
acid, and nonacals were present in the same shirt prior to exposure to an exercising person.
noic acid. In addition to these
Malodors form various sites on the body when natu- acids, several pyrazines were detected along with 2-nonral secretions are converted to volatile odorous chemicals enal, an unsaturated aldehyde with an unpleasant greasy
through microbial activity. Short chain volatile fatty acids and grassy odor, which was primarily found in subjects 40
VFAs (C2-C5) are the primary axillary malodors formed; years old or older. Results from one study indicate that16-androstene steroids and thioalcohols have also been 2-nonenal is generated by the oxidative degradation ofidentified as contributors along with 3-Methyl-2-hexe- omega-7 unsaturated fatty acids and suggest that 2-nonnoic acid (3M2H) [3]. Following the successful combined enal may be involved in the age-related change of body
PDMS and EG-Silicone Twister extraction of volatile odor [4]. According to the study, the change of the monoorganic acids from beer, the same Twister combination unsaturated fatty acid composition of skin surface lipids
was used for analyzing functional T-shirts treated with and the increase of lipid peroxides associated with aging
antimicrobial chemicals and contaminated with perspi- may be involved in the formation of this characteristic
ration to monitor production of various axillary malodor odor component.
Table I shows results for unsoiled control cotton shirt
chemicals.
samples spiked with five levels of various volatile acids
Experimental
and 2-nonenal ranging from 10 to 500 mg/L. Excellent
The combination Twicester® approach was investigated least square correlation coefficient and detection limits
using HSSE. One gram of soiled fabric was suspended are demonstrated for all acids and 2-nonenal. Figure 3
from a paper clip protruding through the septum of a 40 shows a chromatogram of axillary malodor volatile acids
mL glass vial. A Teflon coated micro-stir bar was placed extracted from a soiled shirt by HSSE with PDMS andat the bottom of the vial (to agitate the air in the vial) and EG-Silicone Twisters.
A separate SBSE method was developed to deterone 1 cm x 0.5 mm PDMS Twister and one EG-Silicone
Twister were attached to the sides of the vial with mag- mine androstenone, in which the PDMS Twister was
netic clips (GERSTEL Twicester®). The Teflon stir bar desorbed at 270 °C for 5 min (instead of 220 °C for 5
was stirred at 800 rpm, and the vial was thermostated at min used for the EG-Silicone Twister-based work). It is
50°C. Extraction was conducted for 2 h. The two Twisters worth remarking that Soini et al. [5] developed a novel
were removed from the vial and desorbed in the GER- tool for using a PDMS Twister to extract volatile organic
STEL TDU using the method parameters previously malodorants directly from the skin. The stir bar, which is
described for the beer analysis except with a maximum attached to a miniaturized holder that looks like a mindesorption temperature of 220 °C (instead of 280 °C) to iature paint roller, is rolled over a determined area of aprotect the EG-Silicone Twister from thermal decompo- human skin while collecting a representative sample of
VOCs from the skin surface.
sition.

5

78

Table I: Calibration curve results for five concentrations of axillary malodorant standards in the 10 to 500 ppb (mg/L) range analyzed by HSSE methodwith 1 PDMS + 1 EG-Sil Twister. XIC = extracted ion mode; SIM = selected ion mode.

Standard

Mass Ion

Detection Limit (ppb)butyric acid

60 (XIC)5

0.9921

HSSE

isovaleric acid

60 (XIC)5

0.9731

HSSE

pentanoic acid

60 (XIC)5

0.9737

HSSE

hexanoic acid

60 (XIC)5

0.9972

HSSE

octanoic acid

60 (XIC)

100.9911HSSE

2-methybutanoic acid

74 (XIC)5

0.9655HSSE

3-methyl-2-hexenoic acid 113 (XIC)

10

0.9901HSSE

2-nonenal

70 (XIC)

50.9900HSSE

272 (SIM)

0.4

0.9914

SBSE

Androstenone

20

Linear Least Sqauares Correlation Coefficient

Analytical Method

GERSTEL Solutions worldwide – No. 16

Complaint Casein Powders
with Musty Off-Flavor
Due to its flavor stability and functional properties, casein powder is commonly used in cheese analogues,
bakery products, meat products, confectionery products,
desserts, nondairy coffee creamers, and beverages. Several
complaint casein powders from various international foodand beverage companies were received in our laboratory.
These had extreme musty taints and were implicated as
causes of expensive product recalls involving cereal bars,
nutritional beverages, a chocolate-flavored beverage, andnondairy coffee creamers in the U.S.
Musty off-flavors are commonly associated withmicrobial metabolites such as trihaloanisoles, geosmin(trans-1,10-dimethyl-trans-9-decalol), 2-methylisoborneol, and 2-isopropyl-3-methoxy pyrazine. These compounds have such low odor detection thresholds that theymust be detected in the ng/L range making determination challenging (2,4,6-trichloroanisole odor threshold:
0.15-2.0 ng/L; geosmin: 1-10 ng/L). These compounds
have relatively large log Ko/w values, however, allowing
PDMS Twisters to extract them very efficiently from anaqueous sample or aqueous suspension of a solid sample.
Indeed, SBSE GC-TOFMS was found to be a sensitiveand simple technique for the determination of these compounds in casein powders.
Experimental

1 g of casein + 25 mL water was stirred 30 min at room temperature with a Teflon coated stir bar, which was then replacedwith a 2 cm x 0.5 mm PDMS Twister and stirred for threehours. The Twisters were thermally desorbed in a GERSTELTDU using the parameters previously indicated.
Results and discussion
The primary musty off-flavor chemicals found in the casein were trichloroanisole isomers formed by microbial
methylation of 2,4,6-trichlorophenol, a common ingredient in fungicides, pesticides, and wood preservatives.
In extracted ion chromatograms at 212, 195, 196 and161 amu, haloanisole peaks were readily apparent. The
major haloanisoles identified were 2,4-dichloroanisole,
2,4,6-trichloroanisole (at 7 mg/L), and 2,3,6-trichloroanisole contaminated with coeluters.
In resolving the product recall lawsuits, it was important to provide supporting evidence that the substrate
2,4,6-trichlorophenol was also present in the complaint
caseins. The source of the trichlorophenol was found tobe the wooden shipping pallets that the bags of casein
were stacked on during overseas shipment.
Interestingly, testing of additional complaint casein
samples revealed the presence of 2,4,6-tribromoanisole(2,4,6-TBA), the source of which was identified as theslip sheets used when stacking the bags of casein duringtransport. These sheets were manufactured from recycledplastic, mainly high-density polyethylene, contaminatedwith tribromophenol (TBP), likely stemming from theuse of organobromine flame retardants, such as polybroGERSTEL Solutions worldwide – No. 16

minated diphenyl ethers (PBDEs). Standard calibration
curves for 2,4,6-TCA demonstrated correlation coefficients (R2 values) greater than 0.99. For TBA testing,samples were spiked with deuterated TBA at 133 mg/L.
Stable Isotope Dilution Analysis (SIDA) is arguably oneof the most accurate quantitation techniques for the determination of organic compounds by GC-MS.

Conclusion
The application examples presented in this article demonstrate that SBSE and HSSE have been successfully extended to a wide variety of sample matrices. The new polar phase EG-Silicone Twister has significantly extended
the application potential of SBSE and HSSE to include
analytes that were difficult to extract at high recoveries
with PDMS. Twister technology combined with thermal
desorption-GCMS can be applied to a broad spectrum ofsample types using SBSE and HSSE, making the Twistera significant analytical tool to assist the flavor chemist
in off-flavor and malodor elucidation of a wide profile ofnon-polar and polar analytes covering a broad range ofanalyte volatilities and concentrations.

References[1] R. Marsili, C. Laskonis, C. Kenaan “Evaluation of PDMS-based
extraction techniques and GC-TOFMS for the analysis ofoff-flavor chemicals in beer”, Journal of the American Societyof Brewing Chemists 2007, 65(3), 129-137. DOI: 10.1094/
ASBCJ-2007-0617-01[2] N. Ochiai, K. Sasamoto, H. Kanda, E. Pfannkoch “Sequential stirbar sorptive extraction for uniform enrichment of trace amountsof organic pollutants in water samples”, Journal of the American Society of Brewing Chemists 2008, 1200(1), 72-79. DOI:
10.1016/j.chroma.2008.05.069[3] A. Natsch, H. Gfeller, P. Gygax, J. Schmid “Isolation of a bacterial
enzyme releasing axillary malodor and its use as a screening
target for novel deodorant formulations”, International Journal of
Cosmetic Science. 2005, 27, 115-122. DOI: 10.1111/j.14672494.2004.00255.x[4] S. Haze, Y. Gozu, S Nakamura., Y. Kohno, K. Sawano, H. Ohta, K.
Yamazaki “2-Nonenal newly found in human body odor tends toincrease with aging”, Journal of Investigative Dermatology. 2001,
116, 520–524. DOI:10.1046/j.0022-202x.2001.01287[5] H. Soini, K. Bruce, I. Klouckova, R. Brereton, D. Penn, M. Novotny“In situ surface sampling of biological objects and preconcentration of their volatiles for chromatographic analysis”, Anal. Chem.
2006, 78, 7161-7168. DOI:10.1021/ac0606204 CCC

Suggested reading
Written from a practical perspective, the second edition of Flavor, Fragrance, and Odor Analysis highlights the powerful SBSE
technique and emphasizes therange of applications available.
Ray Marsili (Edi.),Flavor, Fragrance, andOdor Analysis,
Second Edition, 280 Pages,
ISBN-10: 1439846731 andISBN-13: 978-1439846735.

21

Image: istock / selvanegra, PauraDesign

Mycotoxin Monitoring

Nine steps forward
Laboratories are constantly under pressure to improve productivity – many times without the additionof human resources. To support this demand, more and more scientists are turning to automationof their time consuming and costly manual sample preparation procedures. This article describes
how scientists at a contract laboratory specializing in food and environmental analysis developed andimplemented an automated SPE-HPLC-MS/MS multi-method to determine nine mycotoxins in one
run without relying on immunoaffinity cartridges or human intervention.
By Franziska Chmelka, Mariia Matkovskaia and Norbert Helle,
TeLA GmbH, Geestland, GermanyTheir Latin names seem almost regal, and those whoknow their powers are aware that the molds Aspergillus parasiticus and Aspergillus flavus should be treatedwith the utmost respect. They should be admired only
from a safe distance, with proper protection, and neveringested. Luckily, the visual and olfactory appearance ofmolds is not appealing to humans and we are geneticallyprogrammed to avoid them, but they are not always visible to the naked eye, nor do they necessarily have an odor.

22

Among the metabolites of these molds are potent toxins
known as mycotoxins. Apart from being acutely toxic they
have carcinogenic, genotoxic and endocrine disrupting
traits [1].

Only the dose makes the poison
While Paracelsus obviously was right for most poisons,much more detailed toxicological knowledge at a moGERSTEL Solutions worldwide – No. 16

Aflatoxin B1: 8,0 µg/kg (Peanuts),
0,1 µg/kg (Baby food); Sum total of aflatoxins
B1, B2, G1 and G2: 15 µg/kg (Peanuts), 4,0 µg/kg(Grain)Ochratoxin A: 10 µg/kg (Coffee, raisins),
0,5 µg/kg (Baby food)
Zearalenon: 200 µg/kg (Corn/Maize),
20 µg/kg (Baby food)T-2-/HT-2-Toxin: not yet establishedFumonisin B1: 2000 µg/kg (Corn/Maize),
200 µg/kg (Baby food)

Image: TeLA GmbHlecular level is available to today’s scientist. The dose considered toxic for some mycotoxins would have surprised
the old master, since for these it is safe to assume thatany measurable amount could be unsafe. Whoever processes grain, fruit, spices and other agricultural products
should know that is not a question of whether these contain molds, but rather how much they contain. Molds are
ubiquitous and cannot be eliminated, only controlled. Accordingly, depending on their individual toxicity, European Union (EU) lawmakers have established maximum
levels of mycotoxins in food and feed with a special viewto protecting the youngest humans [2]:The mycotoxin multi-method for the determination of nine mycotoxins
was successfully automated on an LC-MS/MS system from Agilent
Technologies in combination with a GERSTEL MultiPurpose Sampler (MPS
Dual Head version). The solvent gradient used was (A: 5 mM formic acid,
B: Acetonitrile; Flow: 0.2 mL/min, 50 °C). The stationary phase used was
a C18 reversed phase (RP) material. Mycotoxins were detected in positive
ESI Mode.

and the time spent per sample could be reduced significantly, of course provided thequality of results were comparable or
could even be improved. A further
positive point was that all steps could
be automated using a standard sampler

Challenges in standard mycotoxin analysis
When maximum levels for toxins are established, this
implies that adequate analysis methods and technologies
are available with which these levels can be accurately
determined and our food quality monitored. Standard
methods prescribe the determination of mycotoxins infood and feed in separate groups of analytes using HPLC
and fluorescence detection with a clean-up process basedon Solid Phase Extraction (SPE) using immunoaffinity
cartridges. For some, namely aflatoxins and fumonisin, aderivatization must be performed [3]. An HPLC-MS/
MS method is specifically required only for T-2 and HT2. Standard methods used for the determination of mycotoxins are of course effective in that they produce correct
results, but they generally offer significant potential for
optimization in terms of productivity. In addition, the useof immunoaffinity cartridges is quite expensive and several different cartridges and clean-up steps are required
for each compound group making the total analysis verytime consuming.

Realizing the optimization potential
Upon closer inspection, it seemed feasible to dramaticallyincrease the efficiency and productivity of our mycotoxin
analysis. Several steps of the process were analyzed andthe optimization potential determined. Among otherthings, it became clear that a major bottle neck was theneed for multiple SPE process steps for different groupsof mycotoxins. If these could be combined into one SPE
step based on a standard sorbent cartridge, the need for
expensive immunoaffinity cartridges could be eliminated
GERSTEL Solutions worldwide – No. 16

Most Unwanted
Aflatoxins
Aflatoxins are formed as secondary metabolites by different
Aspergillus species, including Aspergillus flavus and Aspergillus parasiticus. These are mainly found in nuts and spices.
Aflatoxins are highly toxic and carcinogenic; the most critical
Aflatoxins are the types B1, B2, G1 and G2. Aflatoxin B1 is theone most frequently found in food. Aflatoxins are thermallystable and are therefore not destroyed by cooking.

Ochratoxins
Next to the Aflatoxins, Ochratoxin A is counted among themost dangerous mycotoxins. Ochratoxin A is known tocause kidney damage and animal experiments have shown
it to be carcinogenic. This mycotoxin is often found in coffee,
cereals, beer and dried fruits. As is the case for Aflatoxins,
Ochratoxin A is thermally stable and is not even destroyed
during coffee roasting.

Fusarium toxins
Fusarium toxins are produced by various Fusarium species
among others and are frequently found in cereals. Amongthese are Zearalenon, T-2 Toxin and HT-2 Toxin. Their acutetoxicity is considered low.

Fumonisins
Fumonisins are strongly polar mycotoxins formed by themolds Fusarium verticillioides and Fusarium proliferatum,
the most potent of these toxins is Fumonisin B1. Fumonisins are found everywhere in the world. They are formed
especially on corn/maize, the amount formed on grains orin foods depends mainly on environmental factors and on
storage conditions. Fumonisins are water soluble and are
not deactivated by most food preparation processes.

23

Image: TeLA GmbH

Automated
SamplePreparation
makes thedifference
Following the method
development work, theautomated sample preparation process was implemented as follows: The SPE cartridge was conditioned
using methanol and water and a 7 mL sample was added
to the cartridge. The packed bed is washed with 4 mL ofwater and dried with nitrogen gas. The analyte elution is
performed using 1.5 mL acetic acid ester. The vial withthe eluate is transferred to the MultiPosition Evaporation Station (mVAP) and the eluate evaporated to dryness. The residue is taken up in 500 µL of the mobile
phase and injected to the separation column. In summary,the goal of developing a fully automated multi-method
for the determination of mycotoxins was reached and themethod implemented for the following compounds: Aflatoxin B1, B2, G1 and G2, Ochratoxin A, Zearalenone, T-2
and HT 2 Toxin as well as Fumonisin B1. The simplified
analysis process with unified sample preparation steps for
all mycotoxins lead to significant time savings compared

Chromatogram of a standard mixture of the mycotoxins Aflatoxin B1, B2, G1 and G2, Ochratoxin A, Zearalenon,
T-2- and HT-2 Toxin as well as Fumonisin B1.

for sample preparation and introduction to the LC-MS/
MS system, reducing the laboratory workload. Finally,using MS/MS technology instead of fluorescence detection would improve both the specificity and the sensitivity of the analysis. Following a great number of carefully
calibrated experiments, the mycotoxin multi-method wasestablished for the determination of the mycotoxins Aflatoxin B1, B2, G1 and G2, Ochratoxin A (OTA), Zearalenon(ZEA), T-2- and HT-2 Toxin and Fumonisin B1. The
system used for the analysis consisted of an Agilent 1290
HPLC with 6495 Triple Quadrupol Mass Spectrometerfrom Agilent Technologies in combination with a GERSTEL MultiPurpose Sampler (MPS) in Dual Head configuration equipped with two towers. This version enables
different types of process steps to be processed efficiently
without the need to change tools.

Calibration Aflatoxins
AFLA B1
0.1 - 10 ng/mL
R 2= 0.999

Calibration Ochratoxin A
AFLA G1
0.1 - 10 ng/mL
R 2= 0.999

OTA
0.1 - 10 ng/mL
R 2= 0.999

Calibration Fumonisin
AFLA B2
0.1 - 10 ng/mL
R 2= 0.999

AFLA G2
0.1 - 10 ng/mL
R 2= 0.999

Fumonisin B1
0.1 - 10 ng/mL
R 2= 0.999

HT-2
0.5 - 50 ng/mL
R 2= 0.999

ZEA
0.5 - 50 ng/mL
R 2= 0.999

T-2
0.5 - 50 ng/mL
R 2= 0.999

Excellent linearity over a wide range of concentrations for all compounds.

24

GERSTEL Solutions worldwide – No. 16

Image: TeLA GmbH

Calibration FusarinsMycotoxin

Level [µg/kg]

Recovery [%]RSD [%]

Fumonisin
T-2		

2

79

5.4

2

105

6.1

HT-2

2

103

6.5

OTA

2

88

4.3

Aflatoxin G2

2

94

5.7

Aflatoxin G1

2

91

4.8

Aflatoxin B2

2

95

4.5

Aflatoxin B1

2

89

3.9

ZEA		

2

108

5.9

Validation data for the mycotoxin Multi-method for the determinationof nine mycotoxins.

with the traditional manual sample preparation process.
By using parallel processing of sample preparation steps
and chromatography analysis (PrepAhead function) the
analysis time was reduced to 52 minutes for the first sample and 30 minutes for all subsequent samples.

Results more than satisfactory
Using a solid phase extraction for sample clean-up instead of performing costly clean-up steps with immuno-

affinity cartridges enabled us to reduce the cost per analysis significantly. Furthermore, fluorescence detection was
replaced by much more sensitive and selective MS/MS
detection, leading to lower limits of determination (0.10.3 μg/kg). Statistical values were good, average recoveries
ranged from 94.6 percent and upwards and Relative Standard Deviations averaged 5.2 percent. Calibration curves
for all mycotoxins showed excellent linearity from 0.1 to10 ng/μL (Aflatoxins, Ochratoxin A and Fumonisin) and
0.5 to 50 ng/μL respectively (T-2, HT-2 and Zearalenone). Our routine analysis implementation showed that
the Mycotoxin Multi-Method was rugged and reliable.

References[1] Fast and reliable answers regarding aflatoxins in foods,
GERSTEL Solutions Magazine No. 7, pp. 18-21
www.gerstel.com/pdf/solution_07_18_21.pdf[2] COMMISSION REGULATION (EC) No 1881/2006 of 19
December 2006 setting maximum levels for certain
contaminants in foodstuffs[3] Improving MS Detection of Aflatoxins using Automated Solid
Phase Extraction and Derivatization coupled with an LC/MS
System, GERSTEL AppNote 6/2007

GERSTEL NEWS
Thermal Desorption Unit – TDU 2
The new GERSTEL Thermal Desorption Unit (TDU 2) is the heart of the most flexible
and powerful sample introduction platform available for your GC/MS.
he TDU 2 is a fourth generation Thermal
Desorption instrument from GERSTEL, building on more than 20 years of experience. The
TDU 2 offers the highest performance, new low
split pneumatics for improved LODs, built-inalignment support for easy liner change, and automation performed by the MPS robotic offeringhigh precision delivery of samples, Barcode reading capability and up to 240 TDU tube sample
capacity in standard configurations.
The TDU 2 enables ultra-trace analysis of awide range of samples. Mounted directly on topof the CIS inlet without the need for a transfer
line, the TDU provides a completely inert sample
path for best possible analyte recovery.
The GERSTEL MultiPurpose Sampler (MPS/MPS robotic) is extremely versatile. The system
performs automated spiking of adsorbent tubes
with liquid standards as well as multiple sample introduction techniques such as Liquid, HS,
GERSTEL Solutions worldwide – No. 16

SPME plus the following seven:• Thermal Desorption of sorbent
packed tubes• Direct Thermal desorption/extractionof solids• Thermal Extraction of liquids in μ-vials• Dynamic Headspace – DHS and DHS
Large (1 L)• Hot injection and trapping (HIT) for HS• Stir Bar Sorptive Extraction (SBSE)• Pyrolysis using the GERSTEL PYRO

Image: GERSTEL / Wolfram Schroll

T

It is extremely easy to add – or switch between – sample introduction techniques. All
techniques are fully controlled by GERSTEL’s
powerful, yet easy to use MAESTRO software.
The complete integration of MAESTRO into
Agilent’s GC/MS software allows set up throughdropdown menus and combined storage and reporting of all method parameters.

25

Image: Istockphoto / joyt

Company NewsGERSTEL expands in Southeast Asia
Ever increasing demand for intelligently automated solutions from GERSTEL has made it necessary to
expand into larger offices in Singapore to more efficiently support customers and partners/distributors
in South East Asia. GERSTEL LLP held an opening celebration at the new premises that was attended
by prominent local officials as well as by key GERSTEL partners and customers. Everybody agreed that
this was an important step towards a promising future for GERSTEL in the region.
By Guido Deussing

S

Image: GERSTEL

ingapore is not just a great place to live, boasting one GERSTEL management, Eberhard G. Gerstel, Holgerof the highest standards of living in Asia; it is also Gerstel and Ralf Bremer, on their choice of location andan excellent place to run a company. The “Lion State” praising the company’s decision to increase the presence
has for decades beenin the region as a sign
an important andof sound judgment
reliable partner for
and a basis of further
German businesses
growth. Prof. Lange
according to Professtated that the Southsor Dr. Thomas A.
east Asia business
Lange, Chairman of
hub offers a first classthe Board of Direcbusiness environment
tors of the Nationwith significant comalbank AG in Essen,
petitiveadvantages
Germany,
GERincluding a second to
STEL’s partner banknone infrastructuresince 1967, when
and a highly qualified
the company was
workforce.
founded by Eberhard
For the inauguraGerstel Sr. Professor Left of the pillar, the guests of honor (from left) Dr. Tim Philippi, Executive Director /tion of the new GERMember of the German/Singaporean Chamber of Commerce, Dr. Sascha Kienzle,
Lange was speak- Board
STEL LLP offices,
Head of the Science and Technology Department of the German Embassy in Singapore,ing at the inaugura- Professor Dr. Thomas A. Lange, Chairman of the board of NATIONAL-BANK AG in Essen, GERSTEL manageProfessor Hian Kee Lee, Faculty of Sciences of the National University oftion of the new and Germany,
ment and the regional
Singapore, Dr. Khim Hui Ng, Scientist of Firmenich Asia Private Ltd., Hooi Yan Moy, envoy
largerGERSTEL for the Health Sciences Authority in Singapore. To the right of the pillar (from left): Ralf
team led by Ms. Tan
General Manager GERSTEL GmbH & Co. KG, Ms. Tan Surakanpinit Regional
LLP offices in Singa- Bremer,
Surakanpinit had inSales Manager South East Asia, Eberhard G. Gerstel and Holger Gerstel, Managing
pore, congratulating Directors and Co-Owners.
vited customers, part-26

GERSTEL Solutions worldwide – No. 16

Image: GERSTELGERSTEL management (from left): Ralf
Bremer, Holger Gerstel and Eberhard
G. Gerstel go through a Singapore style
dedication ritual.

respected world-wide and it certainly applies to GERSTEL products”, says Holger Gerstel. “But the label
is not a guarantee for a successful global presence that
requires first class products, which are well supported”.
Ralf Bremer adds: ”If you want success internationally,
you have to go where the markets and the customers
are and this is exactly what we are doing, while making absolutely sure not
to neglect our strong home base in theGerman market”.
“GERSTEL is experiencing good
growth as shown by the fact that wehave had five consecutive years of increased revenues, with internationalsales growth of 20 percent from 2013
to 2014”, says Eberhard Gerstel.
Ms. Tan Surakanpinit, Regional
Sales Manager South East Asia is responsible for GERSTEL LLP activities. Ms. Surakanpinit has worked in
the analytical instruments business inAsia, the US and Europe and is intiImpressions from the inauguration of the new GERSTEL LLP offices in Singapore. Guests got amately familiar with the South Eastbehind the scenes look at the application laboratory.
Asia region. The GERSTEL LLP ofAccording to the GERSTEL management team, fices have separate service and application support dethe expansion in Singapore was overdue: “The interna- partments with highly qualified regional staff to assist
tional business revenue has steadily grown over the past customers in the time zone. At the same time, the supyears and in 2014, it made up more than 60 % of to- port staff is well connected with GERSTEL colleagues
tal company revenues”, says Eberhard G. Gerstel. “Our world-wide such that they have access to company-wide
GERSTEL K.K. subsidiary in Tokyo has supported the product knowledge. Other apJapanese market extremely successfully over the past ten plication labs are located inyears. The demand for GERSTEL systems and solu- Europe, the US and Japan, andtions in Singapore, China, South Korea and large parts all cooperate very closely sinceof South East Asia have made it mandatory to have a analytical chemists are facing
solid support structure in the region outside Japan, of- more or less the same chalfering technical and application support for GERSTEL lenges all over the world.
customers and partners from the same time zone”.

Image: GERSTEL

ners and guests from business and government. GERSTEL LLP was founded in 2010 as the fifth GERSTEL
company outside Germany. The four others are based in
the USA, Switzerland, Japan and Brazil. GERSTEL is
also represented in over 70 other countries by carefully
selected and trained distributors.

Global growth of a German company
Since the company was founded in 1967, GERSTELHeadquarters have been in Mülheim an der Ruhr, Germany, where products are developed and produced.
“The label “Made in Germany” is well recognized and
GERSTEL Solutions worldwide – No. 16

GERSTEL LLP Tan Surakanpinit,
Regional Sales Manager
The Alpha #02-18 · 10 Science Park Road
Singapore 117684 Telefon +65 (6779)
0933 E-Mail: tan_surakanpinit@gerstel.com

27

Image: Guido Deussing

Well stocked: When they compose new flavor
and taste compounds, Lars Grohmann (left)
and Uwe Schafer from Symrise AG in Germany
have access to thousands of ingredients.

Automated Sample Preparation

The Perfect Blend
In order to always be one step ahead of the competition, Symrise AG relies on innovative productconcepts combined with strategies that take a long term view. By automating and miniaturizing a key
process, the Germany based global player has succeeded in increasing the productivity of its flavors
and fragrances development in a sustainable manner, reducing the use of costly ingredients.
By Guido DeussingW

hen management spurs an organization on to question standard procedures and to try new approaches
in order to improve products and processes, an innovation
drive can be set in motion that releases a lot of creative energy within a short period of time. This is what happenedin the German company Symrise AG. The Symrise company group was formed in 2003 by a merger between theGerman companies Haarmann & Reimer and Dragoco.
Today, Symrise is among the top three companies in the
global flavors and fragrances market. It is the stated intention of the company to continue growing faster thanthe market.

28

cations and markets such as the food and consumer goods
industries. When they create new flavors and fragrances,
the flavorists rely on a large number of very different raw
materials and ingredients, each of which can consist ofa multitude of compound mixtures. The ingredient concentrations, depending on their flavor intensity, can range
from a few ppm to as much as 90 percent in the final mixture. Accurately producing a new flavor or fragrance withsuch a wide concentration range of components requires
technical know-how and the right equipment in addition
to the flavorist’s creativity.

The key to success

Miniaturization improves flexibility
and reduces cost

Creating conditions for growth is easier said than done,
but a company that can afford to take a long-term viewon investment while continually working on process improvement is off to a promising start. Key parameters inworking towards continual improvements and success areproductivity, flexibility and sustainability, the latter meaning reducing the amount of energy and other resources
spent at all levels. This is the approach taken by the Analytical Department of Symrise, which has a key role in thedevelopment of flavors and fragrances for different appli-

Blending new flavors for sensory evaluation is typically atime consuming and labor intensive task that requires asignificant amount of expensive ingredients. Speeding up
flavor development requires automation. If automation
can be combined with miniaturization of the blending
process, significant savings can be achieved. If the automated system is capable of running 24/7, good efficiency
and productivity is also ensured.
Automated blending devices used in flavor and fragrance development are obviously capable of reducing the

GERSTEL Solutions worldwide – No. 16amount of labor required, but they typically require a lotof bench space as well as large amounts of the often very
expensive ingredients. Since one key goal of Symrise forthe entire organization is to operate with minimal use ofresources, miniaturization of the blending process was a
key objective from the very beginning of the project.

For many years, the analytical laboratories at Symrise
have been relying on the GERSTEL MultiPurpose Sampler (MPS) to automate sample preparation and sample
introduction in combination with GC/MS analysis. The
MPS-based systems in the lab are, among other things,
configured for liquid injection, various static and dynamic
Headspace techniques as well as extraction techniques
including Solid Phase Micro-Extraction (SPME). Since
2005, the company has also used an MPS WorkStationequipped with an integrated balance for simple extraction
procedures. The MPS is extremely well suited for handling and transporting the tiniest amounts of sample andstandard solutions and dispensing them with high accuracy. This gave the flavor experts Uwe Schaefer and Lars
Grohmann the idea that they could miniaturize the flavor
blending process using the MPS, and greatly reduce thequantities of ingredients used in the process. “The resultsof the initial experiments we performed clearly indicatedthat we were heading in the right direction”, the flavor
experts reported.

Key capabilities for clean
and accurate work
From a technical point of view, the MPS Dual HeadWorkStation offers a wide range of sample handling options. The system can be configured with many different
tools as well as with a range of heated or cooled trays ofdifferent dimensions. If liquid addition steps have to beverified and documented with the highest accuracy, a laboratory balance can be integrated into the workflow. To
prevent contamination and sample to sample carry over,
Symrise chose to configure the MPS WorkStation with
Dynamic Load and Wash (DLW) technology: “Between
the needle and the syringe barrel, there is an inert sample loop through which a well-defined amount of flavor
ingredient is sampled”, Lars Grohmann explains. At nopoint does the sample or ingredient get into contact withthe liquid syringe. Finally, before the next liquid volume
is aspirated, the sample loop and needle are thoroughly
rinsed from above using solvents that are approved foruse within the flavor industry. The solvents are dispensed
from a dedicated DLW solvent station.

Even innovative hardware requires
thoughtful implementation
When developing flavors and fragrances, Symrise relies onapproximately 2500 different ingredients. Among theseare pure raw products, essential oils, and extracts. Because
many of these ingredients can degrade when exposed to

GERSTEL Solutions worldwide – No. 16

Image: Guido Deussing

The MultiPurpose Sampler –a powerful blending device

The MPS WorkStation accelerates the development of new fragrancesand flavors, increasing both productivity and throughput. The system canoperate around the clock – 24/7.

heat, it was decided that Peltier cooled tray stacks were thebest option for ingredient storage. Three stacks with thecapacity to hold 6 trays per stack were used in the final configuration. These were vented in order to eliminate the possibility of flavor and fragrance emissions and possible crosscontamination. This provided the MPS Dual Head WorkStation with a capacity of 204 to 918 ingredients dependingon the vials and trays used. For example, VT12 trays holdup to twelve 10 mL vials; VT54 trays offer 54 positionsfor 2 mL vials. If only VT12 trays are used, a maximumof 204 ingredients can be stored in the system that was
configured in cooperation with Symrise; if only VT54 trays
are used up to 918 positions
are available. The remaining
Symrise AG
18th tray is used for diluents
Symrise develops, produces and sells
and solvents. Through carefragrances, flavors, cosmetic active ingreful optimization, the flavor
dients, raw materials and functional ingreexperts at Symrise and theirdients as well as sensorial and nutritional
GERSTEL project partners
solutions. These are typically key functional
ingredients in the final products produced
succeeded in accommodatingby the customers of Symrise. The bulk of
all essential raw products northe approximately 30,000 products availamally needed for flavor develble are based on natural raw products
opment work using a single
such as vanilla, citrus fruits, flower petals
MPS WorkStation.
and other plant material. Symrise’ customers include manufacturers of perfumes,
To assist in the technicalcosmetics, food and beverages, the pharimplementation of the blendmaceutical industry and producers of nuing process on the MPS Dualtritional supplements as well as pet foodHead WorkStation, Symriseand baby food.
developed a database tool,
which stores and takes into
account specific product data including relevant ingredientspecifications such as specific density and viscosity. In addition, the Symrise database keeps track of ingredient usage
and stock levels in the MPS WorkStation. An integrated
export function directly transfers the “recipe” of ingredientsand their associated quantities for a particular fragrance
blend directly to a MAESTRO Software Prep Sequence
for automated blending.
In the development project, a strict and indispensablecondition laid out was the ability to identify raw products
by unique product numbers as well as to pinpoint their

29

Image: Guido Deussing

Successful cooperation

A strong team: During the development of the MPS blending device,
GERSTEL R&D manager Dirk Bremer (Middle.) and GERSTEL SalesManager Michael Groeger (right) worked closely with Lars Grohmann(left) and his colleague Uwe Schaefer.

exact vial and tray position. The overall implementationand integration of the database with the MAESTRO
control software required multiple project steps in which
the impact of the parameters chosen on the wider software project always had to be considered carefully. “Thesystem alerts the user when ingredient stock is low andshould be replenished or if an ingredient is missing altogether and should be added”, Uwe Schaefer and Lars
Grohmann report.

The flavor experts from Symrise and the application andsoftware experts from GERSTEL were able to draw oneach other’s expertise, pooling their knowledge to produce an impressive solution. The task was among otherthings to expand the possibilities of the MAESTRO
software and to enable the desired features such as stock
management, data transfer, weighing, data tracking – and,last but not least, miniaturization. “Instead of dispensing
milliliters or larger volumes by hand, the MPS performs
the job dispensing only a few µL of an ingredient in order to create a new fragrance”, Uwe Schaefer and Lars
Grohmann report: “The automation and miniaturizationof the process using the MPS WorkStation resulted insavings in raw product usage of up to 80-90 %”.
According to the flavor experts, the MPSWorkStation works day and night, eight days a week
when needed. That means the MPS is working overtime
and the flavor experts have more time to challenge conventional wisdom in the operation and to try out new
things. In short: More time for creative work – the mostimportant thing in the flavor and fragrance business.

GERSTEL NEWS
Images: GERSTEL / Wolfram Schroll

GERSTEL MPS with
SID 1D/2D Barcode
ReaderT

he new Sample ID (SID) 1D/2D Barcode
reader for the GERSTEL MultiPurpose Sampler (MPS) uses a dual camera setup and image
analysis for positive identification of samples.
SID can be connected to a PC or via LAN using
USB connectivity. Fully implemented into theMAESTRO software, SID enables independent
sample logging or fully integrated sample ID
transfer to the data file with multiple userdefined options for sample verification and thehandling ofdeviations.

30

GERSTEL quickMix

The quickMix is an option for the GERSTEL MPS
family of samplers. It enables extremely fastand efficient mixing and extraction of a sample aspart of the automated sample preparation process.
The mixing power is comparable to that of vortex
mixing. The sample is agitated in a special tray on
the module, depending on the vial size holding up
to 6 samples at a time. The tray can be exchanged
to operate with 2 mL, 4 mL, 10 mL and 20 mL vials.
If needed, quickMix can be configured with a heated tray. All sample preparation steps are set up by
mouseclick in the MAESTRO software in stand-alone
operation, fully integrated with Agilent MassHunter or
ChemStation, or coupled with software from SCIEX™
or Thermo Scientific®.

GERSTEL Solutions worldwide – No. 16

Application

Conducting E&L Studies more efficientlyT

During thermal desorption, analytes are concentrated in
the cold trap and subsequently transferred quantitatively
to the GC/MS column whereas
only an aliquot of liquid extracts areanalyzed resulting in less favorable
limits of detection. Results
obtained on a quadropole GC/MS
system were controlled using highresolution GC-QTOF-MS leading
to a highly interesting correction of
the results reported. In summary,TD screening enables a wide rangeof analytes to be determined withmuch lower limits of detection
and GC-QTOF can help remove
any doubt as to the identity of aleachable compound.

Image:: GERSTELo safeguard the health and well-being of patients, it
must be ensured that no harmful chemical compounds
can leach from packaging into a pharmaceutical productbefore it is administered or taken. This is done byconducting Extractables & Leachables (E&L) studies
on pharmaceutical products in their packaging andby screening the packaging for potential extractable
and leachable compounds, for example, using direct
thermal desorption of the packaging material. Thermal
Desorption (TD) coupled with GC/MS analysis
has proven a highly efficient and sensitive screening
method. Chemical compounds that are extractable andleachable are likely to be suitable for thermal extraction.
TD Screening gives a first rate overview of potential
contaminants covering a wide polarity range [1].
Application experts from Agilent Technologies and
GERSTEL have now expanded the range of TD-related
methods used for E&L studies to polymer based bloodbags (IV bag systems) [2]. In this work, direct thermal
extraction of the IV bag system material was used toprovide an overview of the volatile compounds present.
Hoffmann et al. then went one step further to extract
and concentrate leached compounds from the IV bag
content (simulants) using Stir Bar Sorptive Extraction(SBSE) based on the patented GERSTEL Twister. The
added value of this approach: Labor and time-intensive
solvent-based extraction and concentration procedures
are eliminated. The GERSTEL Twister has a large
sorbent phase volume enabling efficient extraction withgood recovery resulting in high overall sensitivity of theanalysis and low detection limits. In addition, the absenceof an extraction solvent reduces the number of interfering
compounds and eliminates solvent peak masking.

References[1] Michael Jahn, Armin Hauk, Illegal Migration from Packaging, GERSTEL Solutions
Worldwide No. 10 (2010) 20-23,
http://www.gerstel.com/pdf/GST_GSW_10_20_22.pdf[2] Elizabeth Almasi, Andreas Hoffmann, Thomas Albinus,
Kurt Thaxton, Extractable and Leachable Analysis of IV
Bag Systems using Direct Thermal Extraction of Materials and Stir Bar Sorptive Extraction of Aqueous Solutions
coupled with Thermal Desorption Gas-Chromatography
with Unit Mass and High Resolution Mass Spectrometric
Detection, GERSTEL AppNote 02/2015(www.gerstel.com/pdf/p-gc-an-2015-02.pdf)

GERSTEL NEWSGERSTEL MPS liquid

T
Image: GERSTEL / Wolfram Schroll

he new MPS liquid is a highly efficient liquid
autosampler for GC/MS and LC/MS analysis work.
Focusing on the core tasks of an autosampler, the
MPS liquid offers large sample capacity, modern
intuitive software control, as well as the capability
to perform key sample preparation steps suchas the addition of internal standards ora derivatization reagent. The
MPS liquid helps you ensurethat your laboratory offers fast,
responsive and productive
analysis work while delivering
reliable and accurate results.

GERSTEL Solutions worldwide – No. 16

31

Preview – coming up in the next issue

www.gerstel.com

Chlorinated water andthe consequences

Image: Jan Garbe-Immel

Polymer break-down
products

Imprint

Using a clever combination of a widelyused extraction technique for GC/MS
analysis, breakdown products from thermogravimetric analysis (TGA) is efficiently
concentrated and accurately determinedby GC/MS. The role of Stir Bar Sorptive
Extraction (SBSE) based on the GERSTELTwister in this work is revealed in the next
issue of GERSTEL Solutions Worldwide
Magazine.

Image: GERSTEL / Wolfram Schroll

GERSTEL online: Information on products, applications, events and downloads, as well as e-Newsletter subscription and general information about
GERSTEL and our customer focused
solutions:www.gerstel.com and www.gerstelus.com

Published by
GERSTEL GmbH & Co. KG
Eberhard-Gerstel-Platz 145473 Mülheim an der Ruhr, Germany
Editorial director
Guido Deussing, Neuss, Germany
guido.deussing@pressetextkom.de
www.pressetextkom.de
Scientific advisory board
Dr. Eike Kleine-Benne
eike_kleine-benne@gerstel.de
Dr. Oliver Lerch
oliver_lerch@gerstel.de
Dr. Malte Reimold
malte_reimold@gerstel.de

Efficient multi-vitamin
analysis

Translation and editing
Kaj Petersen
kaj_petersen@gerstel.com
Image: Creativ Collection

Determining fat soluble vitamins can becumbersome, but it doesn’t have to be:
Using an intelligent sample preparation
strategy and the right technology, fat soluble vitamins can be efficiently determinedusing a multi-vitamin analysis method.
Franziska Chmelka, Mariia Matkovskaia
and Norbert Helle, Ph.D. from TeLA GmbHin Germany report how it is done.

DesignPaura Design, Hagen, Germany
www.paura.de

ISSN 1616-0078

Water is chlorinated to eliminate or at least
reduce the presence of potentially harmful bacteria. In the process unwanted disinfection byproducts (DBPs) are formed
such as halogenated acetic acids (HAAs),
which could themselves be harmful. Read
more about efficient monitoring of HAAs
and how polymer materials react with disinfection chemicals in the next issue of
GERSTEL Solutions Worldwide Magazine.

www.gerstel.com
www.gerstel.com

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Inc.,Inc.,
USAUSA+1 410+1 410- 247- 247
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