solutions

worldwide

No. 20

Water Quality

PFAS Analysis
Sensory Analysis &Lipid Oxidation
Dynamic Focusing
Air Monitoring
Sustainability
Fountain of YouthMOSH/MOAH

www.gerstel.com

Spring is in the Air - Software Everywhere
Dear reader,2024 promises to be a
big year for Software withexciting new developments:
While MAESTRO continues tobe a huge help and support to thousands of users
world-wide, operating thewidest range of GERSTEL
products and solutions, theall new MAESTRO LabFLow
software for Client-Server
architecture is introduced at analytica 2024 in Munichin April. MAESTRO LabFlow is fully integrated with
Agilent ® Technologies OpenLab®TM software and will
support many routine analysis systems, combining
sample preparation and -introduction with GC-MS or
LC-MS analysis in a more traceable and networked
manner. Also at analytica 2024, new MOSH/MOAH
data handling software will be introduced, enablinghighly efficient and transparent quantitation, data
handling, and customized reporting of MOSH and
MOAH results for improved food safety analysis.
Last, but not least, the ODI 2 software for Olfac-

tometry combined with theworld-wide leading GERSTEL Olfactory Detection Port
technology adds exciting
new possibilities for efficientquantitation and reportingof olfactory analysis, including panel work. Along withnew hardware solutions, weare reporting on GERSTEL’s
longstanding award winning
drive for sustainability, as we have just gone a stepfurther with our recent ISO 14001 certification. In themagazine, several applications are highlighted thatbring benefits to laboratories large and small in termsof excellent efficiency and quality of results alongwith reduced reliance of potentially toxic solvents for
extraction and sample preparation. Please never holdback in asking for more information or contact us todiscuss how we may help make your laboratory work
even more efficient.
Your sincerely,
The GERSTEL team.

CONTENTSPRODUCT NEWS................................................................................................................................................................................................. 3
Only the Nose Knows: IDENTIFYING LIPID OXIDATION OFF-ODORS BY SENSORY DIRECTED ANALYSIS......................................... 4
Dynamic Focusing: A NOVEL CRYOGEN-FREE TECHNIQUE FOR DETERMINING VVOCS, VOCS, AND SVOCS................................ 8
MOSH/MOAH ANALYSIS - efficiently automated.......................................................................................................................................... 10
Water analysis: MONITORING PFAS............................................................................................................................................................... 15
From Green Beginnings to Green Results: GERSTEL’S JOURNEY TOWARDS SUSTAINABILITY............................................................ 18

Superfood: IN SEARCH OF THE FOUNTAIN OF YOUTH: COMPOUNDS THAT KEEP US YOUNG AND LET US LIVE HEALTHIER LIVES... 20
RECENT APPNOTES......................................................................................................................................................................................... 24

IMPRINT
Published by
GERSTEL GmbH & Co. KG
Eberhard-Gerstel-Platz 1 · 45473 Mülheim an der Ruhr
Germany
Reader service
marketing@gerstel.de
ISSN 1619-0076 · 04/2024

Scientific advisory board
Eike Kleine-Benne, Ph.D. · eike_kleine-benne@gerstel.de
Oliver Lerch, Ph.D. · oliver_lerch@gerstel.de
Malte Reimold, Ph.D. · malte_reimold@gerstel.de
Translation and Editing
Kaj Petersen kaj_petersen@gerstel.de
Robert J. Collins rjcollins@gerstelus.com
LayoutPaura Design · www.paura.de

2

Front cover © Copyright: AdobeStock

Imprint................................................................................................................................................................................................................... 2

The new GERSTEL AutoTwister:

Fully automated SBSE / Twister ® workflow
for solvent free “green” extraction
The GERSTEL AutoTwister revolutionizes the solvent-free
extraction process by fully automating the complete
workflow from sample extraction to analysis. This
fully automated system combines the high degree ofautomation that SPME offers with the efficiency of the
GERSTEL Twister® and provides you with several benefits, such as: Excellent sensitivity compared to standard methods(e.g. DIN EN ISO 27108)
 Reduction of manual and repetitive operations
 Minimization of laboratory effort for analysts
 Increase in efficiency
 More sustainable analysis due to reduced consumptionof solvents

Experience
additional and improved functions,such as integrated barcodes in the Twister rods and comprehensive
sample logging which enables traceability as well as
improved quality control. The new GERSTEL quickMIX
provides cooling and heating capabilities. The speciallydeveloped GERSTEL Wash & Dry station improves overall efficiency and sustainability, eliminating potential analyte loss and minimizing water usage. Laboratories canbenefit from reduced solvent consumption, reduced
environmental impact and most importantly reduced
laboratory effort for analysts in the workflow.

Introducing MAESTRO LabFLow Software
The new MAESTRO LabFlow software allows you thepossibility of networked and browserbased work as
well as the use of a client-server architecture in yourlaboratory. Fully integrated into Agilent® Technologies’ OpenLab® software, it supports complete analytical systems and combines sample preparation andintroduction for GC-MS or LC-MS analysis. In addition,
MAESTRO LabFlow software includes a comprehensive audit trail to ensure full traceability of changes.
MAESTRO LabFlow revolutionizes sample preparation
and analysis workflows and comes standard with avariety of predefined workflows. Additional customized workflows can be easily adapted and integrated.
In addition, the software has a clearly defined set ofuser roles and a modern user interface.
Integration into OpenLab 2 software provides anintegrated method editor and enables simplified processes. The advanced MAESTRO LabFlow scheduler
optimizes sample processing and simplifies workflow
management. MAESTRO LabFlow increases efficiency and opens new dimensions for your laboratory.

ISDP: Automating Internal Standard and Dry Purge
Maximize the efficiency and performance of your Thermal Desorption analysis!
The all new GERSTEL ISDP (Internal Standard and Dry
Purge) accessory for Thermal Desorption (TD) offers
fully automated and highly reproducible spiking of 3.5”
TD tubes, including GERSTEL 3.5+ tubes, as prescribed
e.g. in international standard air monitoring methods.
The efficient dry purge function eliminates doubt whenanalyzing samples with high moisture content, while
maintaining high throughput through optimized parallel
processing. Two versions are available:
 GERSTEL ISDP for addition of gaseous standard
 GERSTEL ISDP+ for addition of gaseousor liquid standard as selected by the user

Both ISDP versions enable standard spiking and drypurge for 3.5” TD tubes including GERSTEL TD 3.5+
tubes, which contain up to 30% more sorbent than
traditional 3.5” tubes. Dry purge is performed in
the sampling flow direction to minimize analyteloss. Automated addition of standards extends
the scope and efficiency of TD analysis making it
more efficient, more accurate and more reliable. The GERSTEL ISDP+ has already proven its
worth in air analysis
according to U.S. EPA
Method TO-17 as wellas proficiency tests for
DIN ISO 1600-6.

3

Only the Nose Knows:

Identifying
Lipid Oxidation
Off-Odors by Sensory
Directed Analysis
By Nicole C. Kfoury, Ph.D., Megan C. Harper,
and Jacqueline A. Whitecavage

Introduction
Lipids are vital to human nutrition, providing energy
for biological processes, maintaining brain function,and facilitating the absorption of fat-soluble vitamins[1,2]. Lipid oxidation in food is therefore associated with loss of nutritional value, but as lipids break
down, degradation products that are sensory-active
even at very low concentrations are also formed, resulting in noticeable rancidity off-odors and reduced
customer acceptance[2,3]. Sensory Directed Analysis(SDA) is a process that utilizes gas chromatography incombination with the human nose and mass spectrometry to identify sensory-active compounds. The
use of olfactory and MS detection in parallel enables
determination of sensory-active regions of the chromatogram and simultaneous mass spectral identification of the associated compounds. As a result, SDA
is the ideal technique for solving sensory-related
challenges in food products.
In this study, direct thermal extraction (DTE) anddynamic headspace (DHS) were used as automated,
solventless means of extracting and concentrating
analytes from different sample types. DTE is performed directly in the Thermal Desorption Unit
(TDU 2) to determine volatile and semi-volatile organic compounds (VOCs and SVOCs) at trace levels.
DHS involves purging the headspace above a solid
or liquid sample with inert gas, extracting and thenconcentrating volatiles on a sorbent-filled trap, resulting in improved recovery and extremely low limitsof detection compared with equilibrium headspace.

4 | GERSTEL SOLUTIONS No. 20 | Identifying Lipid Oxidation

TD Multidesorption Mode can be used to stackanalytes from multiple extractions for increased mass
on column in areas of interest where no peak signal isinitially seen.

Experimental
Instrumentation
GERSTEL MPS LabWorks Platform with Dynamic Headspace (DHS), Thermal Desorption Unit (TDU 2), and Olfactory Detection Port (ODP 4) on Agilent 8890/5977C
GC- MSD, GERSTEL Thermal Extractor (TE 2).
Standard Preparation
Standards of hexanal, octanal, nonanal, 2E-octenal,
2E-nonenal, 2E,4E-heptadienal, 2E,4E-nonadienal,and 2E,4E-decadienal were prepared in methanol.
One microliter of the standard was spiked onto theglass frit of a glass thermal desorption tube filledwith Tenax® TA. Dry nitrogen was passed throughthe tube for 3 minutes at a flow rate of 50 mL/min
to purge the solvent. To confirm the identity of thelipid oxidation off-odor compounds, standards wereanalyzed using the same instrument conditions.
Sample Preparation
Fresh and aged canola oil, wheat crackers, and cheddar crackers were analyzed to determine the lipidoxidation off-odors. The canola oil was aged at 40 °C
for several weeks. Wheat and cheddar crackers wereaged at ambient temperature for one year. The very

Table 1: Sensory characteris.cs of fresh, aged, and very age
aged Cheddar cracker sample was aged at 40 °C for
one year. A 50 mg sample of canola oil was weighed
into a slitted micro-vial, transferred to an empty
glass TDU tube, capped with a transport adapter,and placed in a sealed position in a tray on the MPS
robotic autosampler for DTE analysis. A 2.0 g sampleof each cracker was weighed into individual 20 mLscrew-capped vials and placed in the sample tray on
the MPS robotic for DHS analysis.
Sample Introduction
Oil samples were extracted by DTE at 90 °C for
15 minutes with a 50 mL/min helium flow. Analytes
were trapped in the CIS 4 inlet using a glass beadfilled liner at -120 °C. After the extraction was completed, the trapped analytes were transferred to the
GC column in split mode (5:1) by rapidly heating the
CIS 4 inlet to 280 °C.
The cracker samples were incubated in the DHS
module at 40 °C for 2 minutes and then extracted for
20 minutes at 50 mL/min helium flow for a total purge
volume of 1000 mL. Analytes were trapped at 25 °C
on a Tenax®TA packed tube. For analysis, the tubes
were desorbed in the TDU 2 at 280 °C for 3 minuteswith a 50 mL/min helium flow and analytes trapped in
the CIS 4 inlet using a glass bead-filled liner at-120 °C. Following tube desorption, the trapped
analytes were transferred to the GC column in split
mode (5:1) by rapidly heating the inlet to 280 °C.
The GC oven temperature started at 35 °C (2 min),ramping 15 °C/min to 280 °C (2 min). The carrier gas
was kept at a constant flow of 1 mL/min and the column used was a 30 m HP-5MS UI, di = 0.25 mm,
df = 0.25 µm. The MSD was operated in full scanmode (40-350 amu).

Table 1: Sensory characteristics of fresh, aged, and very aged samples

SampleFreshCanola oil

Agedcanola oil, slightoxidized,

green/aldehydic

painty, green,

Very Agedn/aaldehydic
Wheat

cracker, slightcrackers

green/oily

Cheddarcracker, cheddar,slight waxy

crackers

stale, oily,
fatty,

n/aoxidized
stale, oily,
fatty,
waxy

rancid, fatty,
waxy,
chemicalThe fresh samples exhibited the odors expected fromeach respective food product, with only very slight oxidation odors. The aged samples had very characteristic lipid oxidation off-odors, including green, painty,
oily, fatty, waxy, and rancid. To confirm that DTE andDHS successfully extracted the odors of interest fromeach sample, a Thermal Extractor (TE 2) was used torelease and individually assess the total odor extracted from each oil and and each DHS sorbent trap. The
released total extracted odors were assessed by direct
olfactory detection a the TE 2 outlet.

Olfactometry
GC-O analysis was performed with a 2:1 column
effluent split between the ODP and MS. The ODP
Figure 1: Stacked view of total ion chromatograms of aged (top)transfer line was heated to 250 °C. The mixing chamFigure
1: Stacked
view
of total
ion chromatograms of aged (top) and fresh (boIom)
and fresh(bottom)
canolaoil.
canola oil.
ber was heated to 150 °C and purged with humidified nitrogen to prevent olfactory fatigue and nasal
Figures 1-2 show the stacked view of aged (top) andTable 2: Key sensory characteris.cs, iden.ﬁed compounds, and rela.ve peak areas for fresh anddehydration.
freshoil.
(bottom) canola oil and wheat crackers. Figure
aged canola

Results and Discussion

RT

Each sample was initially subjected to direct sensory
4.58
6.01
evaluation to determine the odors of interest associ8.26
ated with lipid oxidation, as shown in Table 1:
8.48

3 shows the stacked viewof very aged(top), aged
CompoundPeak Area(middle),andfresh(bottom)
cheddarcrackers.
The
Fresh
Aged
Fresh
Aged
chromatograms
are overlaid
painty, oily in red
1-Penten-3-one
n.d. with
1.0 the olfactorygreen,
grassygreen, grassy OdorHexanal
1.0
19.2
regions
in yellow.
regions that
represent
keymushroom, green
mushroom, green
1-Octen-3-oln.d.
sensory characteristics
determined
in1.0the samples are

Odor Characteristic

9.18

oxidized

2E,4E Heptadienal

1.0

10.8

green, aldehydic

2E-Octenal

n.d.

1.0

Nonanal

1.0

4.8

9.65

green

green, aldehydic

10.2
6
10.7
0
11.8

cucumber, green

cucumber, green

oily, oxidized

fatty, oxidized

1

n.d.

GERSTEL SOLUTIONS
No.
20 | Identifying
aldehydic
Decanaln.d.
1.0 Lipid Oxidation | 5

Note: n.d. = not detected

2E,4E-Decadienal

n.d.

1.0

marked in blue. There are significantly greater peak signals and moreodor regions in the very aged andaged samples compared to the fresh
samples. The key sensory characteristics detected in each sample, theidentified compounds, and the peakareas normalized to the fresh samples
are shown in Tables 2-3.
The aged canola oil was described asoxidized, painty, green, and aldehyFigure 2: Stacked view of total ion chromatograms of aged
dic. Oxidized and painty odors detected at the ODP(top) and fresh (bottom) wheat crackers.
were identified as 1-penten-3-one, 2E,4E-heptadienal, and 2E,4E-decadienal. 2E,4E-heptadienal wasand 2E-octenal. Some additional compounds weredetected by the MS in both samples but could only be
identified, including acetic acid, heptanal, andsmelled at the ODP in the aged sample, likely because
octanal, as can be seen in Figure 2.The former two
the concentration in the fresh sample was below the
were identified in both the fresh and aged samples
odor threshold. 2E,4E-decadienal, on the other hand,at the MS but were only detected at the ODP in thehas a very low odor threshold and could be detected
aged samples, again suggesting that they are presat the ODP in both samples, but was below the instruent at a concentration below their odor threshold inment limit of detection in the fresh sample.
the fresh samples and thus not contributing to any
Tablegreen
3: Keyandsensory characteris.cs, iden.ﬁed compounds, and rela.ve peak areas for fresh and aged
The fresh canola oil had only a slightoff-odor, as can be seen in Table 3.
wheat crackers.
aldehydic aroma; in the aged sample this was much
In three regions, green and oxidized odors wereRT
Characeristic
Peak Area
more pronounced. Several green andaldehydicOdorodors
detectedat the ODP but not by the MS. The comCompound
Fresh
Aged
Fresh
Aged
were detected at the ODP. Hexanal and nonanal werepounds Acetic
in thetwo1.0regions
around 10.83 and 11.82
4.45
vinegaracid
6.6
assessed as green and aldehydic in both samples but
minuteswereidentifiedbyincreasing mass on col6.04
green, grassy
green, grassy
Hexanal
1.0
5.5
were present at much higher levels7.35
in the aged samumn
throughtheTD
Multidesorption
Mode, as can
green
Heptanal
1.0
7.6
ple. 2E-octenal and decanal were also
described
8.26
mushroom, fatty as
mushroom,befatty seen
1-Octen-3-ol
8.3
in Figure1.04. 2E,4E-decadienal
was previously
green and aldehydic but were only8.58
found in the agedaldehydic, green
Octanaln.d.
1.0
identified
in the canolaoil, but 2E,4E-nonadienal
8.69
oxidized
2E,4En.d.
samples.
was newly
identified
in1.0the wheat crackers. The first
Heptadienal
Many ofFigure
the compounds
identified
in the wheat
1: Stacked viewof total
aged
(top)
and
fresh
region,at
10.28
minutes,
has the same retention time
9.22ion chromatograms
oxidized
oily,ofoxidized
2E-Octenal
1.0 (boIom)
4.7
crackerscanola
were oil.
also found in the canola
oils.
These aldehydic, fatty
9.68
aldehydic
Nonanal
n.d.
1.0
10.28
green, aldehydic
aldehydic, cucumber
n.d.
include hexanal, 1-octen-3-ol, 2E,4E-heptadienal,
10.83

n.d.
Table 3: Key sensory
characteris.cs, iden.ﬁed compounds, and rela.ve

musty, oxidized

musty, oxidized

Table 3: Key sensory characteristics, identified compounds,

musty, wheat
oxidizedn.d.
crackers.
Table 2: Key sensory characteris.cs,11.82
iden.ﬁed compounds,
andpeak
and aged wheat crackers.
andrela.ve
relativepeakareas
areas forfor fresh
fresh and
Table 2: Key sensory characteristics, identified compounds,
aged canola oil.

and relative peak areas for fresh and aged canola oil.
RT

Odor Characteristic

Compound

Fresh
4.58

RT

Peak Area

Aged

Fresh

Aged

painty, oily

1-Penten-3-one

n.d.

1.0

Odor Characeristic

Fresh

Aged
vinegargreen, grassy

green, grassy

4.45
6.04
7.35

Peak Area

Compound

Fresh

Aged

Acetic acid

1.0

6.6

Hexanal

1.0

5.5

green

Heptanal

1.0

7.6

6.01

green, grassy

green, grassy

Hexanal1.0

19.2

mushroom, fatty

1-Octen-3-ol

1.0

8.3

8.26

mushroom, green

mushroom, green

1-Octen-3-ol

n.d.

1.0

8.58

aldehydic, green

Octanal

n.d.

1.0

8.48

oxidized

2E,4E Heptadienal

1.0

10.8

8.69

oxidized

n.d.

1.0

9.18

green, aldehydic

2E-Octenal

n.d.

1.0

2E,4EHeptadienal

Nonanal

1.0

4.8

9.65

green

green, aldehydic

10.2
6
10.7
0
11.8
1

cucumber, green

cucumber, green

oily, oxidized

n.d.

8.26

9.22

oxidized

oily, oxidized

2E-Octenal

1.0

4.7

9.68

aldehydic

aldehydic, fatty

Nonanal

n.d.

1.0

10.28

green, aldehydic

aldehydic, cucumber

n.d.

musty, oxidized

musty, oxidized

n.d.

musty, oxidizedn.d.

aldehydic

Decanal

n.d.

1.0

10.83

fatty, oxidized

2E,4E-Decadienal

n.d.

1.0

11.82

Note:
n.d.
= detected
not detected
Note: n.d.
= not

6 | GERSTEL SOLUTIONS No. 20 | Identifying Lipid Oxidation

mushroom, fatty

Note: n.d. = not detectedand odor descriptor as the unidentified compound in
the canola oil, which could be identified in the very
aged cheddar crackers as 2E-nonenal. In addition to thealdehydes detected in the oils and wheat crackers, fatty
acids and methyl ketones were found in the cheddar
crackers. The fatty acids are found at relatively low
levels in the fresh and aged samples, likely due to theirnatural presence in cheddar [4].
However, the fatty acid levels were drastically increasedin the very aged samples, potentially due to exposure
to elevated temperatures for a prolonged time. Thesefatty acids cause the waxy, fatty, and rancid aromas in
the very aged crackers. Interestingly, 2E,4E-nonadienal
and 2E-4E-decadienal levels increase in the aged compared to the fresh crackers but are no longer present in
the very aged sample. It is likely that these compounds
are breaking down and forming methyl ketones at theelevated temperature, to which the very aged sample
Note: n.d. = not detected
Note: n.d. = not detected
was exposed[1]. The methyl ketones also contribute to
the fatty and rancid odors in the very aged sample. For

more detailed information, please see the associated
GERSTEL AppNote[5].

Conclusion
Sensory Directed Analysis (SDA) can help identify key
sensory-active off-odor compounds formed by lipid oxidation. The data shows distinct differences in chromatography and sensory perception between fresh, aged,
and very aged samples[5]. Notably, the presence orabsence of a compound in the MS chromatogram does
not prove or disprove its sensory impact on the sample. Many compounds were detected by the MS but
produced no detectable odor at the ODP. In contrast,
several compounds were smelled at the ODP, but nopeak signal was seen. Invaluable information is missed
in an MS-only approach. The SDA approach can readily
be used for a wide variety of applications to identify
sensory-active compounds. SDA is a critical tool whencreating high-quality food products and working tomaintain brand loyalty and customer satisfaction.
References:[1] S. Grebenteuch, C. Kanzler, S.
Klaussnitzer, L. W. Kroh, and S.
Rohn. The formation of methyl
ketones during lipid oxidation atelevated temperatures. Molecules
26 (2021).
[2] S. Böttcher, U. Steinhäuser, S.
Drusch. Off-flavor masking of secondary lipid oxidation products bypea dextrin. Food Chemistry 169(2015) pp. 492-498.
[3] P. Goméz-Cortés, G. L. Sacks, J.
T. Brenna. Quantitative analysis
of volatiles in edible oils following
accelerated oxidation using broad
gure 3: Stacked view of total ion chromatograms of very aged (top), aged (middle), and fresh (boIom)
spectrum isotope standards. Food
heddar crackers.
Chemistry 174 (2015) pp. 310-318.
Figure 3: Stacked view of total ion chromatograms of very aged[4] Hayaloglu A. A., Karabulut, I.
(top),
aged(middle),andfresh(bottom)
cheddarcrackers.
Figure 3: Stacked view of total ion chromatograms of very aged (top), aged (middle), and fresh (boIom)Characterization and comparisonof free fatty acid profiles of elevencheddar crackers.
varieties of Turkish cheeses. Int
J Food Prop 16 (2013) pp. 14071416.
[5] Nicole C. Kfoury, Megan C. Harper, and Jackie A. Whitecavage.
GERSTEL AppNote: Identificationof Off-Odor Compounds Associated with Lipid Oxidation in Food
Products Using Sensory Directed
Figure4: TD Multi-Desorption
mode for identificationofigure 4: TD
Mul.-Desorp.on
mode for iden.ﬁca.onof 2E,4E-Nonadianal(A) and 2E,4E-Decadienal (B). Analysis.
2E,4E-nonadienal (A) and 2E,4E-Decadienal (B).

SDA Workshops in the US and Germany

GERSTEL’s
3-day SDA Workshop
designed forofanalyticalchemistsscientists.
Figure4: TD Mul.-Desorp.on
mode forisiden.ﬁca.on
2E,4E-Nonadianal(A)andandsensory
2E,4E-Decadienal(B).The workshop integrates sensory
and instrumental analysis for investigating sensory-active compounds to solve critical challenges in a wide variety of products
and sample types. It includes lectures, hands-on demonstrations, and interactive discussions with our Analytical Services
Group. Interested? Please contact: workshop@gerstel.de

GERSTEL SOLUTIONS No. 20 | Identifying Lipid Oxidation | 7

Air Monitoring and Material Emissions

Dynamic Focusing:
A Novel Cryogen-Free Technique for
Determining VVOCs, VOCs, and SVOCs
Dynamic Focusing for Thermal Desorption is a novel technique in the field of air
monitoring and material emissions analysis that eliminates the need for cryogenic
cooling while delivering exceptional results. Dynamic Focusing enables analyticallaboratories to determine very volatile, volatile, and semi-volatile organic compounds (VVOCs, VOCs, and SVOCs) with high accuracy and precision, low limits ofdetection, and high efficiency.
The graphics on the next page illustrate the dynamic
focusing process.

VVOC, VOC, and SVOC analysis by TD
Dynamic Focusing is a novel cryogen- free technique,integral to the GERSTEL TD Core system, developedfor use in thermal desorption based analysis of air.
Dynamic Focusing is used to focus and trap VVOCs,
VOCs, and SVOCs before releasing them to thegas chromatography (GC) column in a sharp bandfor analysis. The Dynamic Focusing technique has
successfully undergone rigorous testing, including
compliance with methods like U.S. EPA TO-17 andISO 16000-6, and it has excelled in inter-laboratory
proficiency tests.

Understanding Dynamic Focusing:
Dynamic Focusing diverges from traditional thermal
desorption methods in key ways: A single, relatively
weak sorbent is packed into the trap liner, and thetrap temperature is set to +10 °C. Instead of trappingand desorbing in two separate stages, these are
overlapped:
Medium to high boilers are trapped by the sorbent
and desorbed upon heating, while very volatileorganic compounds (VVOCs) are slowed down justenough to be focused into a sharp band, resulting inremarkably sharp peaks.

8 | GERSTEL SOLUTIONS No. 20 | Dynamic Focusing

Precise timing of temperature and flow provides optimum separation

During Dynamic Focusing, the Thermal Desorption tube is
gradually heated to release S-VOCs, VOCs, and V-VOCs on
to a high capacity focusing trap that is kept cool.

As the heaviest compounds reach the trap, it is rapidly heated
so all compounds reach the head of the gas chromatographic
column simultaneously. This ensures optimum separation withthe lowest detection limits.

Benefits of Dynamic Focusing: Streamlined system Design: The TD tube and trap are
directly connected (liner-in-liner) and the GC column isdirectly inserted into the trap, minimizing void volume,and eliminating the need for valves or transfer lines.
This design reduces analyte contact with surfaces that
can impact recovery and cause carry-over.
 PFAS-Free Flow Path: Absence of PTFE (Teflon™) material in the analyte flow path eliminates the potential
for introduction of PFAS-related compounds as wellas the loss of these compounds by sorption into
PTFE, which are crucial aspects of today’s environmental analysis methods.
 Cryogen-Free Cooling: Peltier elements cool the trap
to +10 °C, focusing compounds as volatile as propylene (C3) and covering the full range of analytes forstandard air analysis methods
 User-Friendly-Low Maintenance: Easy to use, maintain, and troubleshoot, resulting in improved system
uptime Wide Range of Applications: Dynamic Focusing issuitable for a range of Standard Methods, including
US EPA TO-17, ISO 16000-6, and ASTM D6196

Chromatogram of a TO-17 gas standard (numerically labeled) and spiked gas
internal standards (alphabetically labeled). Based on Dynamic Focusing and fullscan MS detection.

Cryogen-Free Dynamic Focusing for Thermal Desorption, in a system without valves or transfer lines,
introduces a new level of performance and simplicity
to air monitoring. This innovative technique offers
researchers and environmental scientists a powerful tool to determine very volatile to semi-volatileorganic compounds with high accuracy and precision
combined with high efficiency. By eliminating boththe need for cryogenic cooling and valves & transfer lines in the sample pathway. Dynamic Focusing
streamlines the entire workflow for targeted VVOC,
VOC, and SVOC determination, reliably deliveringhigh quality data while reducing maintenance costand system downtime.

Teflon is a registered Trademark of the
Chemours Company FC, LLC

GERSTEL SOLUTIONS No. 20 | Dynamic Focusing | 9

!

Pollutants infood,packaging
and personalcare products

Quality Assurance and Consumer Protection

MOSH/MOAH analysis - efficiently automatedInstrumental analysis is a critical pillar of consumer protection, especially for foodsafety. To ensure a reasonable cost benefit balance, high laboratory productivity andgood quality of results, leading contract laboratories increasingly strive to automate
their processes. An example is the determination of mineral oil residues in food,
food packaging, and cosmetics.
By Oliver Lerch, Ph.D. and Isabelle Heker
Industrial production, processing and transportation invariably put food at risk of contamination withmineral oil hydrocarbons, which are subdivided into
two chemically distinct fractions: MOSH (Mineral Oil
Saturated Hydrocarbons) and MOAH (Mineral Oil
Aromatic Hydrocarbons). According to the European
Food Safety Authority (EFSA), the MOAH fraction
contains highly potent carcinogenic compounds,
and both fractions accumulate in human tissue. Froma toxicological standpoint and in the best interestof the consumer, food, and food contact materials,
which mainly means food packaging, should bemonitored for the presence of MOSH and MOAH[1].
The same applies to cosmetics, which are of course indirect contact with our skin.

10 | GERSTEL SOLUTIONS No. 20 | MOSH/MOAH

Principle of MOSH/MOAH determination by LC-GC-FID. Normal phase LC separation of MOSH and MOAH and subsequentparallel GC-FID analysis.

GERSTEL MPS robotic-HPLCGC-FID solution for automatedepoxidation and MOSH/MOAH
determination.

Sizing up the application details

Focus on the customer benefit

In MOSH/MOAH analysis, the main points are to
extract mineral oil hydrocarbons from the sample
and subsequently to determine them using a suitable
analysis method. MOSH/MOAH analysis involves
several extract cleanup steps to separate, concentrate, and transfer the MOSH and MOAH fractions
from the sample matrix into a solution that can beanalyzed in a sensitive and robust manner, yielding
accurate results. Interfering matrix compounds suchas triglycerides are removed automatically on the
HPLC column during separation of the fractions.

With the aim of maximizing efficiency, productivity,
accuracy, and precision of the MOSH/MOAH analysis, GERSTEL has developed an integrated systemthat automates sample preparation, including extract
cleanup, and LC-GC-FID determination of both
fractions.

The hydrocarbons contained in the MOSH and
MOAH fractions are determined separately, but simultaneously, in a dual channel gas chromatographysystem using flame ionization detection (GC-FID).
Depending on the sample type and matrix, additional sample preparation steps may be required toeliminate naturally occurring hydrocarbons from theextract. Some samples must be epoxidized prior to
the LC-based fractionation to remove unsaturated
polyenes that would otherwise interfere with the
MOAH determination. Depending on the matrix,
the MOSH fraction must be subjected to a further
cleanup step using an aluminum oxide (AlOx) column
to remove n-alkanes of plant origin.
To sum it up, determining MOSH and MOAH residues in food or cosmetics is a highly labor intensive
task when performing the sample preparation manually. Contract laboratories and routine laboratories
that are measured not only by the quality of theirresults, but also by their productivity and by how fast
results are delivered, are well advised to automate
the process.

The hardware consists of an Agilent 1260 Infinity II
HPLC system and a dual channel GC-FID system (Agilent 8890 GC) coupled by an LC-GC interface (GERSTEL) and combined with a MultiPurpose Sampler(GERSTEL MPS robotic). The system is highly modular
and easily adapted to changes in requirements.
Systems based on the MPS Single Head autosampler fulfill all requirements for efficient automateddetermination of the MOSH and MOAH fractions in
prepared extracts optionally including AlOx cleanup. Dual Head systems additionally enable cleanup
and sample preparation steps such as saponificationand epoxidation using performic acid or m-Chloroperoxybenzoic acid (mCPBA), including high energy
agitation, centrifugation, evaporative concentration,
cool storage of reagents and samples, wash stations
for syringes, and more. Both Singleand Dual Head MPS systems enable maximum efficiency in performing all sample preparation and introduction steps. Optionally, a dedicated module for
AlOx cleanup of the MOSH fraction can be added.

LC-GC coupling
When developing the LC-GC coupling, we focusedon ruggedness and ease of maintenance of the entire
system to maximize system up-time, sample throughput, and laboratory productivity. Our concept
includes a special GC column mounting system thatenables unfettered access to columns and connectors for fast and easy replacement and the column
connector technology used ensures long-lasting gas

GERSTEL SOLUTIONS No. 20 | MOSH/MOAH | 11

tight connections even after multiple instances of disconnecting and reconnecting columns. The user has
full control of all system parameters and pre-columns
are easily rinsed or replaced as needed. The solvent
vapor venting system (GERSTEL Early Vapor Exit, EVE)
uses a novel approach: Valves are unheated for simplicity and for easy replacement of capillary connectors to the EVE. An integrated purge system removes
residual solvent from the valve and connected tubing
for long-lasting rugged operation.
A (MOSH)

MOSH C-Fractions:

B (MOAH)

MOAH C-Fractions:

Total MOSH = Sum of these fractions: MOSH ≥n-C10 to ≤n-C16 (Dark Blue) MOSH >n-C16 to ≤n-C20 (Orange) MOSH >n-C20 to ≤n-C25 (Yellow)
 MOSH >n-C25 to ≤n-C35 (Green) MOSH >n-C35 to ≤n-C40 (Dark Red) MOSH >n-C40 to ≤n-C50 (Light Blue)

Total MOAH = Sum of these fractions: MOAH ≥n-C10 to ≤n-C16 (Dark Blue) MOAH >n-C16 to ≤n-C25 (Orange) MOAH >n-C25 to ≤n-C35 (Yellow)
 MOAH >n-C35 to ≤n-C50 (Green)

Analysis Details
A quick summary of the analysis: Sample cleanup
and fractionation is performed using normal phaseliquid chromatography (NP-LC), based on polarity
differences. The MOSH fraction elutes before the
MOAH fraction using a solvent gradient consisting of
n-hexane (C6H14) and dichloromethane (CH2Cl2). Matrix residues are backflushed from the column using aflow of 100 % dichloromethane before the column isreconditioned and prepared for the following sample
with a forward flow of n-hexane. A UV detector set
to 230 nm is used to verify separation and transfer
to the GC of the two fractions. The UV detector
cannot be used for quantification of the fractions
since many of the compounds contained, and theinternal standards [3], are insufficiently UV-active
and do not deliver equimolar responses. Following
HPLC separation, the large volume fractions (450 µLeach) are transferred directly to the dual channel GC
system with two GC columns in the oven and two
FID detectors for simultaneous determination of the
MOSH and MOAH fractions. Initially, the fractions
are focused and prepared for GC analysis by evaporating the solvent and venting the fumes throughthe specially designed EVE system. Following GC
separation, analytes are detected by FID, a detector
type that delivers well known mass responses forthe range of analytes contained in the MOSH and
MOAH fractions. Quantitation is performed as thesum of all C10-C50 compounds with individually
added sections in accordance with the JRC Guidance[3]. The internal standard mixture used for MOSH/
MOAH analysis includes nine different compounds.
These are used for quantification and as markers andcontrols for both the HPLC fractionation and the GC
separation performance. A separate „retention timestandard“ with 10 compounds from C10 to C50 isanalyzed regularly to determine the prescribed size
ranges.

Benefits of Automation
Figure 2: Unresolved complex mixtures (UCM) of MOSH (A) and
MOAH (B) fractions extracted from an edible oil sample andintegrated using the GERSTEL MOSH/MOAH Data Analysis
software. The colored peak (signal) areas represent individual
c-fractions. The total amounts are calculated as the sum of all
c-fractions between n-C10 and n-C50. The values are includedin the final report. System control of the GERSTEL MPS roboticHPLC-GC-FID solution for MOSH/MOAH analysis is performed
through the MAESTRO software; data handling is simplified
using a dedicated software.

12 | GERSTEL SOLUTIONS No. 20 | MOSH/MOAH

The description above illustrates the complexity of
the MOSH/MOAH sample preparation. Automation
reduces the risk of errors while improving efficiency,
reliability, and reproducibility on a 24/7 basis. Further,
the ease of operation and the process miniaturization
result in improved sustainability while freeing up
analyst time to focus on more pressing tasks such asplanning, data evaluation and reporting. All parts of
the MOSH/MOAH analysis system are under unified
control of the MAESTRO software integrated withthe Agilent OpenLab CDS. Operation is user friendly
and intuitive. Data handling has been simplified by a
dedicated software package for automated MOSH/
MOAH data handling. “Saddle peaks” resulting fromnaturally occurring compounds are clearly visible on
top of the MOSH and MOAH humps consisting of
thousands of mineral oil related compounds. The sizeof each hump is decisive, the peaks on top do notcount, they are automatically disregarded or subtracted by the software. The humps are automaticallyintegrated with a blank chromatogram used as thelower baseline. The results are reported for each size
range as well as for the whole C10 - C50 range. Manual correction of integration parameters is possible atevery step, if required. The software enables the user
to change integration parameters manually as needed after inspecting the results followed by efficient
automated batch reintegration of an entire series ofanalysis results.
Report Generation

Report Generation
Figure 3: Report Generation: Results are presented in one ofseveral standard report formats that are easily customized tomeet individual needs of the laboratory. Data can be exported
in a variety of formats for further processing.

Final Words
The fully automated GERSTEL MOSH/MOAH solution
meets the requirements of international standard
methods. The fractionation is rugged and reliable,
good recovery of the n-alkanes up to C50 as percentage of the n-C20 is achieved, and no significant carryover is seen. Further, the system is reliable for routine
operation, meeting all requirements for occupationalsafety, data integrity, intuitive operation, and ease ofmaintenance. Obtained analysis results correspondwell with reference analyses performed by independent laboratories, which have successfully taken partin round robin tests.

References:[1] European Food Safety Authority (EFSA), Scientific Opinion on Mineral Oil Hydrocarbons in Food, EFSA Journal
2012;10(6):2704, http://bit.ly/2TnvTWb[2] DIN EN 16995 Foodstuffs - Vegetable oils and foodstuff onbasis of vegetable oils - Determination of mineral oil saturatedhydrocarbons (MOSH) and mineral oil aromatic hydrocarbons(MOAH) with on-line HPLC-GC-FID analysis EN 16995:2017-08[3] JRC Technical Reports: Guidance on sampling, analysis anddata reporting for the monitoring of mineral oil hydrocarbons in food and food contact materials (in the frame ofCommission Recommendation EU 2017/84), http://dx.doi.
org/10.2760/208879
Graphics: © GERSTEL GmbH & Co. KG

GERSTEL SOLUTIONS No. 20 | MOSH/MOAH | 13

Automated MOSH/MOAH Sample Prep
Three sample preparation steps are generally used for MOSH/MOAH analysis:

1) Aluminum oxide cleanup2) Epoxidation
3) Saponification
Each of these methods handles a specific challenge in MOSH/MOAH analysis and can be used
independently. It is possible to use only epoxidation or only aluminum oxide cleanup on one
sample type, but it is also possible to use all ofthem consecutively on the same sample.
Cleanup with activated Aluminum oxide (AlOx):
Using activated aluminum oxide allows the removal of n-alkanes of plant origin from the MOSH
fraction that might otherwise interfere with integration of the hump when evaluating the data.
The n-alkanes are retained on the AlOx column
and separated from the target compounds. In
traditional manual sample preparation, single-use glass columns are used. The aluminumoxide has to be activated at 400 °C for 40 h andis discarded after every sample. Unfortunately,
MOAH compounds are retained on the column
as well and the AlOx columnn must be discarded
after each manual cleanup step. As a consequence, when using manual sample preparation,
two complete analyses are required for eachsample: One for MOSH with AlOx preparationand one for MOAH without AlOx.
The GERSTEL solution is online AlOx cleanup
after separation of the MOSH and MOAH fractions, preventing loss of
the MOAH analytes andeliminating the need for aseparate MOAH determination: Aluminum ox-

ide is packed in a column, similar to an LC column,that lasts a few hundred samples (depending on
the matrix) and is connected to the LC system
via a second LC pump. While the MOSH fraction
is passed through the AlOx column, the MOAH
fraction is “parked” in an injection loop.
Following cleanup, both fractions can be injected
into the GC simultaneously, producing MOSH and
MOAH results in a single instrument run. Additionally, this procedure saves immense amounts
of solvent and single-use raw materials comparedto the manual procedure.
Epoxidation: Epoxidation is used to derivatize
olefins to epoxides. Olefins are mainly of plantorigin and may interfere with the MOAH analysis.
Epoxidation increases their polarity and thereby
their retention on the HPLC column causing themto elute after the MOAH fraction. Epoxidation is
performed by the MPS using a GERSTEL quickMIX,
a centrifuge, and a decapper. The decapper isneeded to eliminate siloxane contamination of thesample, resulting from multiple septum penetrations during sample preparation. The process isperformed on-line in the system prior to sample
injection. Epoxidation can be combined withsaponification on a stand-alone MPS WorkStation
used for off-line sample preparation.
Saponification: Samples with high fat content may
need to go through saponification to remove excess fat before introduction to the analysis systemand prevent triglyceride breakthrough in the LC
column. The reaction is fully automated using the
MPS with a GERSTEL quickMIX, GERSTEL mVAP
multi-position evaporation station, Agitator, andCentrifuge to name the main options used. The
system is modular and easily changed or upgraded with additional modules as needed whenrequirements change.
Saponification is performed in batches of up tosix samples for maximum efficiency on a standalone MPS WorkStation and can be combinedwith epoxidation for a total throughput of 36
samples per day without limiting the sample capacity of the MOSH/MOAH analysis system.

14 | GERSTEL SOLUTIONS No. 20 | MOSH/MOAH

Water analysis

Monitoring PFAS

Per- and polyfluorinated alkyl substances, or PFAS in short, are ever present andpersistent in water. Some members of this huge substance class fall under the Drinking Water Directive. The analysis only requires a single milliliter of water and very
little solvent - when online SPE is used.
By Thomas Brandsch, Ph.D.
Per- and polyfluorinated alkyl substances (PFAS) forma family of highly fluorinated organic chemicals, inpart based on carboxylic and sulfonic acids with achain length of four to 18 carbon atoms. Examples
are fluorinated alkyl sulfonates, with perfluorooctane
sulfonate (PFOS) as the best-known unpleasant representative, and fluorinated carboxylic acids, the mostnotorious representative of which is perfluorooctanoic acid (PFOA). Fluoroplastics such as Teflon are alsocounted among PFAS. Tailored PFAS are found in
our everyday consumer products from food packaging and cookware to carpets and clothing. They
are added to cleaning agents and fire-fighting foams
and are widely used industrially, for example in seals,surface coatings and lubricants. When synthesizing
such PFAS, hydrogen atoms of organic compounds
are replaced with fluorine atoms. This means that the
PFAS carbon chain tail is hydrophobic, and the functional head group is hydrophilic. The resulting amphiphilic character explains the use of some PFAS as
surfactants. Unlike classic surfactants, these PFAS are
lipophobic. This means that they repel water as wellas oil and grease. Additional advantages for technicalapplications include their excellent durability when
exposed to heat and aggressive chemicals.

Clear and present danger
to our drinking water
PFAS are extremely stable under natural environmental conditions. Since they are not affected bydegradation processes, they spread in the environment and PFAS that are present in ionic form canaccumulate in water. All PFAS can accumulate in

Figure 1: Schematic diagram of the online SPE process with
automated cartridge exchange (©GERSTEL)GERSTEL SOLUTIONS No. 20 | Water Analyses | 15

repositories adjacent to surface water and groundwater, i.e. in and near our most important drinking water
reservoirs. The PFAS group of substances includes
thousands of substances, 20 of which currently fallunder the EU Directive 2020/2184 on the quality ofwater for human consumption. These 20 substancesof particular concern are suspected of causing liver
damage, cancer, thyroid disease, obesity, and fertility
problems.

Figure 3: Example calibration curves in the range
0.2 – 2.0 ng/L with (PFOA) and without (PFOS)
significant blank. (©GERSTEL)

eluate can be transferred directly and quantitatively
to the HPLC column without intermediate. This leads
to better limits of detection and -quantification evenwhen a much reduced sample volume is used. Indeed,
instead of several hundreds of milliliters, only one mL
is required, in turn also reducing the amount of solvent
used along with the associated cost and occupational
hygiene and environmental impacts.

Figure 2: Example chromatogram for a standard solution (50ng/L) in water with all recorded MRMs. (©GERSTEL)

To minimize the risk of adverse health effects frompotentially contaminated drinking water, EU Directive
2020/2184 defines a total limit value of 0.5 micrograms per liter for all PFAS. For the sum of the 20
substances listed in the directive, the maximum limit
is 0.1 micrograms per liter. Reliable analysis requires a
detection limit of 30 nanograms per liter for the sumof the 20 listed PFAS and 1.5 nanograms per liter forindividual compounds.

Analysis based on just one mL of sample
The German standard method for water, wastewaterand sludge testing, DIN 38407-42, specifies solid
phase extraction (SPE) with subsequent HPLC-MS/
MS determination as the method of choice. How
efficiently the SPE, and thus the analysis, proceeds
depends in no small measure on the solid phaseextraction technology used.
Compared to the conventional SPE, which is described in DIN 38407-42, online SPE with GERSTELSPE xos is based on smaller cartridges. The SPE

16 | GERSTEL SOLUTIONS No. 20 | Water Analyses

Figure 4: Example calibration curves in the range
1 – 10000 ng/L for the first and the last analyte in
the chromatogram.

The use of online SPE in conjunction with a powerfulautosampler such as the MultiPurpose Sampler fromGERSTEL makes PFAS analysis efficient and convenient. The SPE xos system performs all pre-analysis steps
associated with standard SPE sample preparation– from conditioning, loading, rinsing and elution to replacing the cartridges. The MultiPurpose Sampler rinses, and flushes longer chain surface-adsorbed analytes
from, the flow path and from the vial walls onto thecartridge. In this way, memory effects can be reduced

13C4-PFOA

13C -PFBA
4

13C4-PFOA

to an absolute minimum and excellent recovery of all
PFAS compounds is ensured. All this is performed
without intervention by laboratory staff. Following
analyte elution, SPE xos removes the cartridge fromthe mobile phase flow path and prepares the system
for the next analysis. All the while, HPLC-MS/MS
analysis is ongoing. The overlapping sample preparation and analysis runs increase system efficiency
and sample throughput without extending the overall
analysis time. Parallel processing is controlled by the
MAESTRO software and all steps as well as the total
analysis time are displayed in the MAESTRO Scheduler for best possible throughput and planning.

Validation round robin test delivers proofof method feasibility
Directly coupling SPE xos with the MultiPurpose Sampler and an HPLC-MS/MS system has proven successful in determining the 20 PFAS listed in EU Directive
2020/2184 as part of a validation trial for the validation of the EN 17892. The new standard EN 17892
describes the LC-MS analysis of PFAS in water using
direct injection or solid phase extraction (SPE), which
can be performed also as online-SPE. The evaluationof the validation trial was done separately for thedifferent methods, with comparable results for the
performance data. GERSTEL participated in the direct injection and online-SPE parts, and all achieved
results were consistent with the assigned values.
More detailed information on the online SPE-LC-MS/
MS method used by GERSTEL for PFAS water analysis
is available in a separate application note (AppNote
237). In it, the applicability of the method and theaccuracy of the determination are demonstrated
by spiking different water types and performing
replicate analyses. According to DIN 32645 the limitsof quantification were determined from calibration
curves in the range 0.2 to 2 ng/L and were below 1
ng/L for all compounds.

PFOA

PFOA

PFBA

18O2-PFHxS

13C2-PFDoDA

18O2-PFHxS

13C2-PFDoDA

PFHxS

PFDoDA

PFHxS

PFDoDA

Figure 5: Example chromatograms for selected analytes and internal standards in river water, PFBA and PFOA above, PFHxS and PFDoDA below
quantification limit.

More information:
 GERSTEL AppNote 237: Determination of PFAS in
Water according to EU 2020/2184 and DIN
38407-42 using online-SPE-LC-MS/MS GERSTEL Solutions Worldwide Magazine Nr. 19,
2023, pp. 6-9.
 GERSTEL AppNote 247: Determination of PFAS in
Food of Animal Origin using online SPE Cleanup
and LC-MS/MSGERSTEL SOLUTIONS No. 20 | Water Analyses | 17

ENERGY EFFICIENT FACILITIES 2007

MOBILITY

GEOTHERMALELECTRICCOMPANYCARSEFFICIENTTHERMAL
INSULATIONHEAT PUMPSFOR HEATING& COOLING

4

from adepth of

130 m

AWARD

NRW

PRO

MOBILECHARGING
STATIONSCERTIFICATIONS & AWARDSENERGY
BUILDING
OF THE MONTH

Job E-bike
PROGRAMfor Employees

INTERNaL GoGreen PROJECT GROUPECOPROFITCERTIFIED2014

ISO 14001
CERTIFICATIONMEMBERSINTERNAL &FROM ALL
EXTERNALSUSTAINABILITY DEPARTMENTS
PROJECTSANNUALTRAININGSALL
EMPLOYEESCAN SUBMITPROPOSALS

From Green Beginnings to Green Results:
GERSTEL’s Journey towards Sustainability
In an era calling for corporations to step up and assume responsibility, GERSTEL
emerges as a sustainability trailblazer within the analytical instruments business. The
latest result of this long-term commitment is the successful implementation of an Environmental Management System (EMS) certified under DIN EN ISO 14001 standards.
Setting the Stage with ISO 14001

Ambitious Goals, Tangible Results

GERSTEL’s journey towards environmental sustainability was recently continued and extended with athorough examination of our operational processes.
An internal Go Green team was established withmembers from departments across the entire operation to identify environmental aspects with potential
for improvement across the entire organization. The
team’s diverse expertise enabled a comprehensive
assessment of environmental impact across theorganization, from the smallest things like managing greens on the company premises to facilities,
logistics, materials and chemicals usage, ultimately
achieving ISO 14001 certification. Every facet of
GERSTEL’s operations was scrutinized to achieve aholistic approach to sustainability.

With sustainability as a guiding principle, GERSTEL
has set ambitious environmental goals, each contributing to a more eco-friendly future. From reducing
paper consumption and electronic waste to lowering
electricity consumption, the company’s commitment
is not just about meeting regulatory standards but
exceeding them.

18 | GERSTEL SOLUTIONS No. 20 | Sustainability

GERSTEL’s membership in the exclusive club of ISO
14001-certified companies underscores its dedication to environmental responsibility.

The Work Environment
GERSTEL’s commitment extends beyond environmental goals. The company actively engages in social
initiatives, apprenticeship programs, and continuous
employee development. A testament to its dedication to employee well-being, GERSTEL fosters adynamic work environment with flexible hours, teamevents, and health initiatives.

Innovative Practices and Building the Future
The GERSTEL commitment to sustainability is evident
not only in its operations but also in its headquarters.
The building, constructed in 2007/2008 with state of
the art thermal insulation, incorporates sustainable
technologies such as geothermal heating and energy-efficient lighting. Current plans include adding a rooftop
photovoltaic system. Our commitment to sustainability
and environmentally responsible practices run throughthe entire organization, from product development tobuilding sustainability.

GERSTEL customers benefit from automated miniaturized sample preparation systems that significantly reduceor even eliminate the use of potentially toxic solventsin the laboratory, while delivering outstanding performance, improving the laboratory work environment, andreducing overall cost.
GERSTEL is proud to set an example for the industry,
proving that sustainability, environmental responsibility
and business success can go hand in hand. By embracing a holistic approach to sustainability, the company
positions itself for a sustainable future.

SUSTAINABILITY
GREEN ANALYSIS PROCESSESPRODUCTIONPROCESSES

AUTOMATEDANALYSIS

ON SITEREDUCEDSAMPLE AMOUNTREGIONAL
SUPPLIERS

using miniaturizedprocesses

less or no toxic
solvent required

Production centralized
at Headquarters

short distance transportof materials

welcomeEnabling

HOME
OFFICE

PAPERLESS

Transition to thepaperless ofﬁce

PACKAGING

Recycled Packaging Material
used for product shipment

GERSTEL SOLUTIONS No. 20 | Sustainability | 19

Superfood

In search of thefountain of youth:
Compounds thatkeep us young
and let us live
healthier lifes
By Guido Deussing

The biogenic polyamine spermidine has received a lot of attention since it was scientifically shown to slow down the aging process when taken in adequate quantities.
Determining the spermidine levels in foodstuffs requires the right analysis strategy
given that many have a highly complex matrix. Scientists at the Westphalian University in Recklinghausen, Germany have developed an efficient, fully automated method
based on HPLC-TOF-MS to determine spermidine in the “superfood” Apilarnil.
Wish and Reality
According to the Federal Statistical Office, life expectancy in Germany has almost doubled in the past
100 years: Girls born between 2020 and 2022 will live
to an average of 83.2 years. On average, boys die
five years earlier at 78.3 years old. But that doesn’t
for a minute stop us from wanting to live even longer
and healthier lives. Life can be understood as anatural process, which after a point is characterized
by progressive impairment of cell functions. Aging ispart of life, but can it be slowed down?

in small quantities. Anti-agers and longevity seekers,
among many others, want to know what makes thisdiet so valuable. It has been scientifically proven thatthe intake of certain foods has a positive effect on a
person’s lifespan.
Life expectancy at birth
Average life expectancy (in years)
72,4

Men
Women
59,9

Eat, Drink and be Merry
Regarding what determines our lifespan and qualityof life, what we eat seems to be of great importance.
There is widespread belief among nutritional expertsthat the Mediterranean diet, for example, has a positive effect on our health and can prolong life [1]. The
diet includes large helpings of fruits and vegetables,
as well as legumes, wholegrain products, and olive
oil; add fish, milk and wine in moderation and meat20 | GERSTEL SOLUTIONS No. 20 | Superfood

44,5
35,6

75,0

62,8

66,9

76,5

83,4

71,7

48,3

38,5

1871/1891

1901/1910

1932/1934

1960/1962

1986/1988

2019/2021

the autophagy process stalls, but can apparently bereactivated with the compound spermidine, as theresearcher from the Institute of Neurophysiology atthe Hannover Medical University (MHH) states [4].

Breaking Bad Habits
According to a Norwegian study, it is worth breaking bad eating habits even in old age, for example,
avoiding fast food, eating less meat, and insteadeating more legumes and whole grain products.
After finishing their study [2], Fadnes et al. concluded
that a 20-year-old can gain more than ten years oflife with the right diet, and an 80-year-old more than
three years of added life. At number one on the listof valuable foods are legumes such as lentils, beans,and peas. According to Fadnes et al., whole grain
products and nuts are just as healthy as legumes.
Fruit, vegetables, and fish also have a positive influence on a person’s potential lifespan. Red meat andprocessed products such as sausage and ham havea negative impact, while eggs, poultry, processedcereals, and sugary drinks don’t have much impact.
Foods with antioxidant and anti-inflammatory properties counteract cell damage and age-related
ailments such as cardiovascular disease, cancer,
diabetes, and neurodegenerative diseases, such as
Alzheimer’s. Given that not everyone is able to eat
the optimal amount of healthy food day in and dayout, adding suitable dietary supplements is sensible.
The European Food Safety Authority (EFSA) for one
considers it helpful to compensate for nutritional
deficiencies by maintaining an appropriate intake of
relevant nutrients [3].

Cleaning and Recycling
One age-related change in the human body is that
cellular cleansing processes deteriorate. The socalled autophagy is a type of recycling system thatbreaks down and removes unnecessary or damaged
cell components, explains Evgeni Ponimaskin. This
molecular clean-up mechanism keeps cells fit andprotects against many diseases. However, as we age,

Picture caption (left hand side): Spermidine is an
endogenous, natural substance, a polyamine first
discovered in human semen, which gave the substance its name. We now know that spermidine isfound in all cells in the body and that certain intestinal bacteria produce it as shown here. However, themajority must be absorbed through food. The foodstuffs that are known to contain the largest amountsof spermidine are wheat germ, cheese, especially
Cheddar, soy products and legumes, and most of all
in Apilarnil.
Relative Extraction Recovery(normalized to 1-Hexanol)

100
90
80
70
60
50
40
30
20
10
0

1-Hexanol

Cyclohexanol Ethylacetate

MTBE

Figure X: When extracting spermidine from Apilarnil, 1-hexanol
achieved the highest relative yield.

Heart and Mind
The anti-aging effect of spermidine has been examined in more detail by Ponimaskin and his researchgroup in cooperation with the University of Grazbased on animal experiments [3,4]. The researchers
administered spermidine through drinking water toaged mice for six months and compared the results
after the feeding period with those of untreatedanimals of the same age. As Ponimaskin and his teamreport, clear anti-aging effects were observed in thetreated animals. The spermidine intake ensured thatthe animals developed less kidney and liver damage
and improved the performance-enhancing glucose
supply in the brain. Age-related hair loss was alsosignificantly lower than in the control group. The
animals supplied with spermidine hardly showed any
bald spots on their backs as normally seen in older
mice.
The heart-protecting effect of spermidine was particularly interesting to the scientists. In their studies,
they report finding that the cardioprotective effect

GERSTEL SOLUTIONS No. 20 | Superfood | 21

DCM

is associated with reduced telomere shortening inheart muscle tissue. Telomeres protect the ends ofchromosomes, carriers of genetic information storedin our body cells, fromdegeneration. Each
Nutritional supplements containtime a cell divides,
ing alpha-ketoglutarate, hyaluronthe telomere ends are
ic acid, NAD+ boosters, vitaminshortened slightly.
D3 and vitamins B7, B9 and B12
In cells that are noare advertised as “longevity
longer dividing - suchproducts”. As part of his rejuveas heart muscle cells
nation treatment, the billionaire- the telomeres are
Bryan Johnson takes 13.5 mg offurther shortened
spermidine in his “The Green
until a critical length
Giant” smoothie every morning,
is reached and soapparently with some success incalled programmed
reversing the aging process. The
cell death occurs. To“Blueprint” rejuvenation project
their delight, the recan be followed on his Webpage
searchers found that[5]. As recent studies suggest [4],telomeres in the sperspermidine does appear to influmidine-supplemented
ence the aging process.
mice were similar inlength to those inyoung animals. Since
the aging processes in the cells of mice are similar to
those in human cells, taking spermidine, for example
as a dietary supplement, could also protect against
age-related problems in humans, while strengthening
cognitive processes and memory. To check whether
the results from the animal model can be transferredto humans, researchers from Austria and Germany[6,7] used data from the Bruneck study. A group of829 participants with normal cognitive performancein 1995 was selected. Those of the subjects who had
developed cognitive impairments over the following
five years of observation were identified using theneuropsychological test battery CERAD (Consortium
to Establish a Registry for Alzheimer’s Disease). The
domains of memory, executive functions (planning)
and language skills in the brain were examined.
Spermidine intake from food was then determined.
The results show that study participants who in-

22 | GERSTEL SOLUTIONS No. 20 | Superfood

gested more food with high spermidine levels, such as
wholegrain products and legumes, in 1995 showed significantly less cognitive loss over the following five years.

Experiments and Evidence
Various studies have produced reliable evidenceof positive effects of spermidine on human health.
Examples are: Improved autophagy, reduced risk ofcancer, improved cardiac health, effective protection
against Alzheimer’s and Parkinson’s, reduced risk ofdeveloping type 2 diabetes, as well as a reduction inhigh blood pressure, as Prof. Dr. Ingo Tausendfreundfrom the Westphalian University in Rechlinghausen,
Germany explains. The Bruneck study by researchteams from Graz and Innsbruck with 829 test subjects even showed that people whose diet was rich inspermidine had a significantly lower risk of dying overthe 20-year observation period.

Valuable and Content Rich
Foodstuffs that are rich in spermidine have been
categorized as “superfoods”, to be used for life-prolonging and rejuvenation treatment plans. The following foodstuffs are valuable sources of spermidine(Spermidine content listed per 100 g): avocado (1.0mg), potato (1.2-1.7 mg), hazelnuts (2.1 mg), mango(3,0 mg), cauliflower and broccoli (2.6-3.7 mg), pear(5.2 mg), peas (6.5 mg), shiitake mushrooms (8.9 mg),aged cheddar (19.9 mg) and wheat germ (24.0 mg).
Those more interested in business aspects can takenote that a market analysis for “superfoods” hasprojected growth from 165 billion US dollars in 2023
to 269 billion US dollars in 2028 [8].
Speaking of superfoods: Beekeepers (apiarists) in
Germany offer ostensibly performance enhancing
bee preparations under the name Apilarnil an extractof freeze-dried and powdered drone larvae, whichcontains spermidine, beta-carotene, choline, vitamins
A, E, B1, B2, and B6, as well as numerous minerals(calcium, phosphorus, sodium, potassium, and magnesium) along with trace elements. The discovery
that drone larvae extract can be a valuable nutritional supplement came from a chance observation:
Ducklings fed drone honeycombs grew faster than areference group.

Bee Larvae Prepared
A company specializing in the marketing of apiary
products approached to determine the spermidine
content in freeze dried drone larvae, a challenging
task due to the complex biological matrix. A completely automated approach was required to process
large numbers of samples. LC-MS/MS was identified
as the method of choice; diode array detection (DAD)
would require considerable added sample prepara-tion effort and derivatization steps with added uncertainty. The planned analysis steps were: 1. Selective
extraction of the biogenic amine spermidine from thematrix; 2. Chromatographic separation; 3. Determination with a quadrupole time-of-flight (QTOF)-MS.
In initial work, 1-hexanol was found to produce thehighest relative extraction yield as shown in the
Figure on page 21. 1,7-diaminoheptane was added
as internal standard in a standard addition process.
Using the GERSTEL MultiPurpose Sampler (MPS)
robotic, the researchers performed preliminary
tests, optimizing the process regarding the sample
amount, internal standards used, calibration strategy,
and various method parameters (volumes, mixing
times, centrifugation, wash cycles, needle penetration depths, etc. (For details on the method, pleasecontact info@gerstel.de).
The MPS robotic, equipped with quickMIX and centrifuge enabled complete automation of all steps
in the workflow from sample preparation to sample
introduction. The analysis was performed using an
Agilent 1260 UHPLC with a Restek Force Fluorophenyl column (3.0 μm, 150 x 2.1 mm) using a solvent
gradient. Mass-selective detection was performed
using an Agilent QTOF 6546 (Dual AJS ESI source) inpositive mode (TOF-only). The analysis can also be
performed using an LC-MS/MS system (precursor ion
m/z 146.00, daughter ion m/z 72.00).

Results and Outlook
A series of apilarnil samples were analyzed with
spermidine levels ranging from 310 to 459 mg/kg,
averaging 386 mg/kg. The relative standard deviationof the determination was 1.5 percent with linearity (R2)
greater than or equal to 0.999. The analysis method
was successfully developed and automated basedon the MPS robotic-LC-QTOF system. The following are amounts of spermidine per 100 g: Peas: 6.5
mg; aged cheddar: 19.9 mg; wheat germ: 24.0 mg.
Apilarnil weighed in at a whopping 38.6 mg per 100 g.
Whether it can extend our life expectancy – or keep us(feeling) young remains to be seen.

Standard addition 63 QTOF

Mass concentration SPD [mg/l]
Standard Addition calibration curve for spermidine in Apilarnil
demonstrating excellent linearity

The automated method can be used to determine
spermidine levels in other foodstuffs if the buzz
surrounding spermidine continues. The hope is thatfinding other sources of this promising nutrient will
ultimately lead to more and extended well-being for
the wider population.
References:[1] Crous-Bou M, Fung TT, Prescott J, Julin B, Du M, Sun Q, Rexrode
KM, Hu FB, De Vivo I (2014), Mediterranean diet and telomere
length in Nurses‘ Health Study: population based cohort study, BMJ
2014349:g6674, https//doi.org/10.1136/bmj.g6674[2] Fadnes LT, Okland JM, Haaland OA, Johansson KA (2022), Estimating impact of food choices on life expectancy: A modeling study.
PLOS Medicine 19,3:e1003962, https://doi.org/10.1371/journal.
pmed.1003962[3] https://www.efsa.europa.eu/en/topics/topic/food-supplements[4] Wirth A, Wolf B, Huang C K et al. (2021), Novel aspects of ageprotection by spermidine supplementation are associated with preserved
telomere length, GeroScience 43:673-690, https://doi.org/10.1007/
s11357-020-00310-0[5] https://protocol.bryanjohnson.com/Home[6] Schroeder, Hofer, Zimmermann, Pechlaner et al. (2021), Dietary
spermidine improves cognitive function. Cell Reports 35, https://doi.
org/10.1016/j celrep.2021.108985[7] Yong Tian Liang et al. (2021), eIF5A hypusination, boosted by dietary
spermidine, protects from premature brain aging and mitochondrial dysfunction. Cell Reports 35, https://doi.org/10.1016/j.celrep.2021.108941[8] https://www.mordorintelligence.com/industry-reports/superfoods-market

GERSTEL SOLUTIONS No. 20 | Superfood | 23

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