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. 17

Tattoo Ink:
A Closer Look
Automated Sample Preparation

Efficient Doping
Control with DBS

Water Analysis

Material Analysis

Monitoring Disinfection
Byproducts

VOC Emissions
from PU Foam

CONTENTGERSTEL Solutions worldwide 17

Dear Reader,
The time when only groups on the margins of society
had tattoos is over and long gone. Instead of just adorning
sailors and identifying members of criminal gangs, tattoos
are now prominently displayed by respected
members of society from all walks of life, not justsports stars, artists and musicians. The works ofart range from the very small to larger canvasses
covering major portions of the body.
But what happens if your personal tastes
change and the tattoo no longer fits your life styleor your next career move? It takes time and is very
costly, and dare we say not without risk, to havea tattoo removed as we report in our cover story
on page 7. In the investigations of side effects ofEberhard G. Gerstel
tattoo laser removal, GERSTEL thermal desorption
solutions played a key role.
Apart from the skin deep investigation, the17th issue of the GERSTEL Solutions Worldwide
Magazine offers several interesting reports on application areas in which GERSTEL instruments and-systems are being used. For example, we reporton the use of our Dried Blood Spot Autosampler(DBS A) in doping analysis (page 4) and on thehighly efficient determination of disinfection byproducts in drinking water from page 10 onwards.
Holger Gerstel
Incidentally, the cover picture for the article wastaken by Jan Garbe-Immel from GERSTEL, Germany, an avid photographer who frequently takes
the plunge with his kids in the neighborhood
swimming pool.
Our report on material emissions brings amore volatile note: Polyurethane (PU) is widelyused in building and vehicle interiors. When developing an automated method for the characterization of VOC emissions from PU foams, the
GERSTEL DHS Large was the key player as can be
Ralf Bremer
seen in the article on page 15. But wait, there’s
more: Just like the GERSTEL DHS, our thermal desorption solutions offer solvent free analysis, one of the major
strengths in the GERSTEL portfolio. Why? Read more on
page 19.
From the beginning we have made a habit of visiting laboratories and reporting on their use of GERSTEL
technology for a wide range of applications. Starting on
page 20, we report on a visit to the State Office for Consumer Protection and Food Safety (LAVES) in the Stateof Lower Saxony, Germany, a highly interesting visit thatoffered much insight into automating the generation ofstandards and standard addition for improved quality ofanalysis results.
What else is left to say? – GERSTEL celebrates its 50 th
anniversary in 2017! More on the matter on page 3.
We wish you an enjoyable and interesting read of the
17th GERSTEL Solutions Worldwide Magazine.
		 Sincerely,		

2

GERSTEL Management

Company NewsGERSTEL celebrates its 50th anniversary
From one-man show to internationally acclaimed solutions
provider: The company will be celebrating its 50 th anniversary in October 2017. A fitting occasion to reflect on ourroots and our direction. .................................................................... 3
Automated Sample Preparation

Efficient Doping Control
In the race to keep up with new and suspected doping
agents, the Centre for Preventive Doping Research at theGerman Sport University Cologne, Germany is upgrading
their laboratory with performance enhancing technologies
and automation: The institute is betting on a fully automatedDried Blood Spot (DBS)-LC-MS/MS analysis system. ......... 4
News fromGERSTEL GmbHNo. 17& Co. KG ·Eberhard-Gerste

Consumer Protection

l-Platz 1 · 45473

Mülheim an

der Ruhr ·Germany ·Phone + 49(0) 208 - 76503-0

Tattoo ink: A Closer Look
Tattoo removal using laser radiation can carryhealth risks depending on the breakdown products formed. Scientists have now shown thatpyrolysis GC/MS can be used to simulate the breakdown process and determine the compounds formed froma given ink during laser treatment. .............................................. 7
Tattoo Ink
A Closer :Look

Automated

Sample Preparation

Efficient
DopingControl withDBS

Water analysis

Monitoring
Disinfection
Byproducts

Material Analysis

VOC Emissionsfrom PU
Foam

Drinking Water Analysis

Monitoring of disinfection byproducts
Water is chlorinated to eliminate potentially harmful bacteria. In the process, unwanted disinfection byproducts (DBPs)
are formed such as halogenated acetic acids (HAAs), which
could themselves be harmful, albeit probably to a muchlesser degree. A system which enables much more efficientmonitoring of HAAs is described in our story on page ..... 10
Material Analysis

Indoor Air Care
A fully automated analysis system based on Dynamic Headspace/Thermal Desorption-GC/MS enables fast and efficient characterization of VOC emissions, from Polyurethane(PU) foams, widely used indoors and in vehicles. .............. 15
Laboratory on-site: Visiting LAVES in Oldenburg, Germany

On the Wings of the Condor
The State Office for Consumer Protection and Food Safety(LAVES) in Lower Saxony, Germany, came out on top withthe best results in a Europe-wide round robin test of pesticide laboratories for the determination of pesticides residues
in cereals. GERSTEL Solutions Worldwide magazine visited
the LAVES pesticide laboratories where we joined the staff atwork to gain some insight. ............................................................ 20

Product News ............................................................ 14, 18, 19
Imprint ............................................................................................. 24

GERSTEL Solutions worldwide – No. 17· gerstel@gerstel.
com

Company NewsGERSTEL celebrates its
50th anniversary
From one-man show to internationally acclaimed laboratory solutions provider: the story of
GERSTEL can be summarized in just those few words. The company will be celebrating its 50th
anniversary in October 2017. A fitting occasion to reflect on our roots, celebrate our achievements
and venture a guess on what the future may hold.
By Guido Deussing

berhard Gerstel, born in 1927, husband and father ofthree sons, worked at the venerable Max Planck Institute (MPI) for Coal Research in Mülheim an der Ruhr,
Germany. A talented craftsman and creative precision
mechanic, he developed and built measurement and control instrumentation as well as laboratory equipment for
the MPI scientists. At the time, demand for sophisticatedequipment was soaring and not only at the MPI. Eberhard
Gerstel resigned his position at the MPI in 1967 at age
43 to start his own business. In a garage-turned-fine mechanical workshop in Mülheim an der Ruhr, the company„Labormechanik Gerstel“ was born. The first devices created were all custom built. Initially, his precision mechanics
and engineering skills were fully enough to meet his customers’ demands, but technology is constantly evolving andafter only three years, Eberhard Gerstel’s team counted four
employees, including experts in electronic control technology. The trend was plain to see: Growth. Eberhard Gerstel
developed humidity sensors, contact thermometers andsoon filed his first patent; the company would go on to file a
total of around 200 patent applications by 2017. In the mid
1970s, gas chromatography (GC) became GERSTEL’s
main line of business. The entrepreneur broke into the
GC market with a patented seal technology and a highly
specialized GC inlet system. Eberhard Gerstel successfully
eliminated major limitations of conventional gas chromatographs of the time, adapting them to the newly developed
capillary columns and helping to improve their overall sensitivity significantly. His Cooled Injection System (CIS) became the world’s most successful means of introducing andanalyzing samples by GC using programmed temperature
vaporization (PTV). The opportunities for GERSTEL
continued to present themselves, but they seemed to require delivering more than “just” hardware in order to havefurther growth: Application support was needed in order toensure customer satisfaction and to attract further business.
Eberhard Gerstel brought on a team of chemical engineers,
the company had now grown to a total of
30 employees. Scientists fromother fields followed, manyof whom held Ph.D. degrees,
ensuring that the company

GERSTEL Solutions worldwide – No. 17

had expertise equal to its customers. The company expanded its laboratories and entered into
several strategic partnerships, for example with
Hewlett-Packard in 1986, one of
the world’s leading manufacturersof gas chromatographs and detectors, a business area which waslater split off under the name of Agilent
Technologies. Now GERSTEL was finally able to offer
clients complete analytical solutions, opening up a wealthof opportunities. Eberhard Gerstel Sr. handed the company
over to his sons Eberhard. G. Gerstel and Holger Gerstel
who took the reins along with longtime employee Ralf
Bremer in 1998. The new generation of leadership quickly
accelerated the company’s growth by focusing on international expansion. As early as 1994, the company’s first
US subsidiary, GERSTEL Inc., had opened its doors. In
short order, GERSTEL AG in Switzerland was founded in
2000, GERSTEL K.K. in Japan in 2004, and GERSTELLLP in Singapore in 2010. The company was additionally
represented in more than 70 countries worldwide using a
network of dedicated and trained distributors. In the newmillennium, GERSTEL followed the trend toward automation and miniaturization in the laboratory while critically expanding and deepening our software development capabilities. The steadily growing company has now become
one of the world’s leading providers of innovative solutions
for automated sample preparation and sample introduction
for GC/MS and LC/MS. 50 years after Eberhard Gerstel
Sr. founded his company, GERSTEL’s solutions are wellestablished in in a broad range of markets and fields of application. Our systems are used across many key industries,
in academic research, as well as by food safety and environmental protection authorities. GERSTEL today stands forunparalleled efficiency, performance and productivity in themodern GC/MS and LC/MS laboratories.

© GERSTEL / Wolfram Schroll

E

Maintaining and strengthening the company’s position will also be
the goal for coming generations of GERSTEL management.
And Eberhard Gerstel Sr., who passed away in 2004 at age
77, will look favorably upon it all: From the pillar that bears
his likeness erected in his honor in front of GERSTEL’s
corporate headquarters at No. 1 EberhardGerstel-Platz.

3© iStock / jaco blund

Automated Sample Preparation

Efficient Doping Control
Automated determination of nicotine and its metabolites in blood
In the race to keep up with new and suspected doping agents, the Centre for Preventive Doping
Research at the German Sport University Cologne, Germany is upgrading their laboratory withperformance enhancing technologies and automation: The institute is betting on a fully automatedDried Blood Spot (DBS)-LC-MS/MS analysis system.
By Guido Deussing

T© GERSTEL

he pressure to achieve
Not every chemiDBS Card
SPExosrecord-breaking recal means of enhancCartridge
sults in sports has being physical or mental
come extremely intense,
performance is currently
advances in technololisted as illegal. But theWastegies that can effectively
World
Anti-Doping
guide an athlete to peak
Agency (WADA) has
performance has madea watchful eye on many
achievement of new resubstances that they suscords an almost routine
pect are being used tooccurrence.
However,gain an unfair advantage
LC-MS/MSeven after all aspects of anin sports. In 2015, thePrinciple of Flow Through Desorption (FTD) of a DBS card (left hand side).
athlete’s training regime
watch list sported names
have been optimized andof active pharmaceutical
the seemingly endless hours of preparation have been put ingredients such as Bupropion, Phenylephrine, Phenylin, some athletes still cannot achieve the desired results. propanolamine, Pipradol, and Synephrine, along withThis is when the temptation to use performance enhanc- stimulants such as caffeine and nicotine that are naturally
ing substances rears its head.
present in coffee and tobacco.

4

GERSTEL Solutions worldwide – No. 17

Suggested Reading

In 2011, the German daily Süddeutsche Zeitung reported
that scientists at the University of Lausanne, Switzerland,
had found elevated levels of nicotine in urine samples
from athletes from various disciplines.
“Nicotine doesn’t improve stamina or muscle power,
but it affects the brain and places the athlete in a different state of mind”, says the pharmacologist Fritz Sörgel,a recognized doping expert and Head of the Institute of
Biomedical and Pharmaceutical research (IBMP) at the
University of Nuremberg, Germany. In those sports, inwhich reaction time and concentration are especially important to performance, an increased nicotine level could
help athletes gain an advantage. While smoking tobacco
could have significant detrimental health and performance effects, e-cigarettes or chewing tobacco could
present an attractive alternative without the negativeside-effects.
The same applies to snuff, an orally consumed formof tobacco, which is widely used in Norway and Sweden.
“The suspicion is that snuff is being abused for doping
purposes”, states Professor Mario Thevis from the Centre for Preventive Doping Research at the German Sport
University Cologne, Germany. No clinical studies or other well-founded data were available concerning the use oreffects of nicotine as a performance enhancing drug eventhough WADA had placed nicotine on the watch list as a

World Anti-Doping Agency (WADA)
The World Anti-Doping Agency (WADA) is a foundation initiatedby the International Olympic Committee to promote, coordinate
and monitor the fight against the use of performance enhancing drugs in sports. The agency’s key activities include scientificresearch, education, development of anti-doping capacities, andmonitoring of the World Anti-Doping Code, whose provisions are
enforced by the UNESCO International Convention against Doping in Sport. WADA was founded in 1999, it is an international
non-governmental organization (NGO) headquartered in Montreal, Canada. Wada organizes world-wide campaigns against theuse of doping in sports. These employ urine tests, blood tests
and other tests as required by medical indications. Currently
around 30 laboratories world-wide are authorized by WADA toanalyze the required replicate samples (A and B samples) for
traces of prohibited substances and for signs that prohibited
methods have been used, such as, for example blood doping.
The prohibited list is updated annually and it serves as the international reference for identifying substances and methods prohibited in all sports that fall under the World Anti-Doping Code
(WADC). Individual countries have national anti-doping agencies
such as the USADA in the US, UKAD in the United Kingdom,
AFLD in France and NADA in Germany. Source: WADA, Wikipedia

suspected doping agent. Prof.
Thevis and hiscolleagues in
Cologne along with a scientist from the National Veterinary Institute of the Department of Chemistry in Uppsala, Sweden set out to develop a “fast and inexpensive”
method of analysis that would enable the determinationof nicotine and its metabolites while also providing insight on how they had been introduced into the body[1]. During their search to find the most suitable analysis
technique for their purposes, Dried Blood Spot (DBS)
analysis in combination with online solid phase extraction (SPE) and LC-MS/MS soon emerged as the mostpromising solution.

Cost and speed are the deciding factors
According to the scientists, DBS has proven itself manytimes over, for example in pre-clinical pharmaceuticalresearch; for monitoring of active therapeutic agents; inforensic toxicology; as well as in studies of metabolic disorders. Meanwhile, several examples were also publishedon DBS being used in doping analysis. According toMario Thevis and his colleagues, DBS offers a numberof benefits when compared with standard strategies forblood sampling: DBS is minimally invasive – a simple
finger prick is enough to withdraw a sufficient sample
volume (20 µL) for the analysis. Just a few drops of bloodabsorbed on a suitable, cellulose based medium is all that is needed for a successful
determination of the compounds of inter-© GERSTEL / Wolfram Schroll

Doping with nicotine – more thanjust a suspicion

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 · DOI10.1055/s-0036-1582317,(ht tps://w w w.thieme - connec t.com/
products/ejournals/abstract/10.1055/s0036-1582317?lang=de)

Fully automated DBS system based on theMultiPurpose Sampler (MPS).

GERSTEL Solutions worldwide – No. 17

5© GERSTELDBS desorption is performed with high accuracy in the user-defined
section of the blood spot. Quantitative recovery is achieved resulting inhigh reproducibility.

est. In addition, blood sampled in this way exhibits goodlong term stability at room temperature. Samples dry very
quickly and the absence of humidity means that enzymes
are deactivated, as the scientists point out in their article
in the Journal of Pharmaceutical and Biomedical Analysis[1].
To perform DBS analysis, several sample preparation
steps are required: “Currently, the pre-analysis workflow
includes punching out and dissolving each dried blood
spot. Then an extraction is performed with a suitable
solvent, occasionally including ultra-sonication. Further
clean-up steps involve: Protein precipitation, filtrationand transfer of the resulting extract into a sample vial followed by LC-MS/MS analysis”, according to Thevis etal.. Automation is an absolute necessity in order to minimize the significant manual workload and to qualify DBS
sampling for high throughput analysis in a routine laboratory setting.

Commercially available automation
The scientists set out to determine nicotine, the main metabolites nornicotine, cotinine and trans-3’-hydrocotinine(trans-3’-HCOT), as well as the alkaloids Anabasine andAnatabine using a fully automated system: A MultiPurpose Sampler (MPS) and a Dried Blood Spot Autosampler (DBSA) coupled to an online SPE system (SPExos)
all from GERSTEL. This setup was coupled with a highresolution LC-MS/MS system.
Prof. Thevis explains why this setup is different fromprevious systems used in the laboratory: “When using an
online SPE system, we can extract the DBS sample, clean
up the extract, and proceed directly with the analysis”.
Automation is only one important aspect of the system,
according to Prof. Thevis: “Not only does the automated
DBS sample preparation reduce the workload, it also improves extraction efficiency and limits of detection”. The

6patented Flow Through Desorption (FTDTM) technology enables good concentration factors to be achieved
while minimizing the risk of sample to sample carry over.
The Online DBS SPE-LC-MS/MS method was developed using standard solutions at different concentrationlevels, which were spiked into samples from volunteers
who had neither smoked nor consumed snuff. The validation was performed following the recommendationsof WADA and the European Bioanalysis Forum (EBF).
Deuterated analogues were used for quantification oftarget compounds. In order to investigate potential differences in pharmacokinetics, Thevis et al. used their
method on authentic samples, that is, blood samples
taken from cigarette- and e-cigarette smokers, as well assnuff users. The project was set up with permission fromthe local ethics commission, in some countries known as
the Institutional Review Board, whose task it is to protect
human subjects from harm by overseeing research performed on humans or animals. Written permission was
obtained from the volunteers.

Differentiating between normal
consumption and doping
When they developed the method, the authors focused on
optimizing it for reproducibility and workflow efficiency,
according to Thevis and his colleagues [1]. The process
steps that held the most promise for improvement was
DBS elution, SPE cleanup, as well as Mass Spectrometric
Detection. Using the DBS method they developed, theauthors succeeded in determining all target analytes withexcellent precision and accuracy. The limit of detection
for all analytes was 5 ng/mL. The successful analysis ofblood samples taken from real smokers as well as e-cigarette and snuff users demonstrated that the method could
be implemented for routine doping controls as well.
“All target compounds were found in the real samples”, Thevis et al. wrote. Additionally, the statisticalevaluation had shown a significant difference in the ratio
between nicotine and nornicotine concentrations in the
blood depending on whether nicotine was administered
via the lungs (inhalational) or via mucous membranes(buccal uptake). This means that based on pharmacokinetic properties, conclusions can be drawn as to the athlete’s method of consumption and maybe the longer term
pattern of use.

Literature[1] Laura Tretzel, Andreas Thomas, Thomas Piper, Mikael Hedeland,
Hans Geyer, Wilhelm Schänzer, Mario Thevis, Fully automated determination of nicotine and its major metabolites in whole bloodby means of a DBS online-SPE LC-HR-MS/MS approach for sports
drug testing, Journal of Pharmaceutical and Biomedical Analysis 123(2016) 132–140

GERSTEL Solutions worldwide – No. 17

© iStock / bowie15

Consumer Protection

Tattoo ink: A Closer Look
Tattoo removal using laser radiation can carry health risks depending on the breakdown products
formed. Scientists from the Federal German Institute for Risk Assessment and Consumer Safety
have now shown that pyrolysis GC/MS can be used to simulate the breakdown process anddetermine the compounds formed from a given ink during laser treatment. Phthalocyanine blue
(B15:3), for example, was shown to form a cell poison in the process. Clear as ink? It is hoped thatpyrolysis GC/MS can help consumer safety agencies determine whether certain tattoo inks should
be approved or banned, in light of possible laser removal treatment.
By Guido DeussingThere can be very good reasons to have a tattoo removed: An allergic reaction to the pigments used; adifferent motif may be required, commensurate with age
and experience; the name embedded in your skin may
no longer be the love of your life; older images may have
faded or not look as good as they once did due to the aging canvas; or the tattoo may stand in the way of your next
career move. In the past, having such a permanent fixture
removed required the use of a scalpel or etching or sanding of the skin - an unpleasant process. Fortunately for
those suffering from tattoo remorse, techniques have recently become available to remove tattoos relatively gently
without leaving visible scars or traces.

Laser treatment is preferred but it is notwithout risk
It may be a gentler treatment than previous generationsof tattooees had to endure, but using a laser could entail
certain health risks. At least that is what a joint study by
the Federal Institute for Risk Assessment and Consumer

GERSTEL Solutions worldwide – No. 17

Safety and the Laser Department of the Elisabeth Hospital points to. Both are located in Berlin, Germany. The
study was published in “Scientific Reports”[1]. In it, Ines
Schreiver, Christoph Hutzler, Peter Laux, Hans-Peter
Berlien and Andreas Luch report that toxic and even carcinogenic compounds are formed during laser treatmentof the copper-containing tattoo pigment phthalocyanine
blue (B 15:3). The scientists simulated the fragmentation
process using pyrolysis GC/MS and compared the fragments formed with laser breakdown products determinedby Dynamic Headspace (DHS) in a separate experiment
involving two-dimensional GC coupled with Timeof-Flight Mass Spectrometry (TOF-MS). Among thecompounds determined were: 1,2-Benzenedicarbonitrile(BDCN), benzonitrile (BCN), 2-butanone, benzene, andhydrogen cyanide as the main fragmentation products.

Laser radiation meets tattoo pigments
In clinical dermatology, ruby lasers are regularly used totreat pigmented spots, i.e. liver spots and to remove tat-7

toos. According to the scientists, radiating
the skin with a ruby laser can lead to temperatures of more than 1000 °C in the skin.
To break down the relatively stable color
pigment phthalocyanine blue (B15:3),
temperatures in excess of 800 °C are required. Bleaching of what is apparently
the only blue tattoo pigment available todermal needle workers is assumed to be
the result of a thermally induced chemical breakdown process (photo-thermolysis) equivalent to an atomization of thepigment, Schreiver et al. report. To avoid
damaging the skin at the high temperaturesgenerated during laser treatment, the energy rich laser light cannot be allowed to emit
continuously, but only in discrete, time-limited
pulses. The ruby laser has a high pulse energy
level making it well suited for medical skin treatment purposes. The efficiency of laser treatment
in breaking down tattoo pigments is well proven.
It can be observed directly by the ink pigment
bleaching effect during treatment. Less clear isthe exact identity and quantity of the resulting
chemical derivatives and their long-term effecton the human organism. To shine a light on thismatter was the stated goal of Schreiver et al. In
order to imitate the laser induced, temperaturedependent decomposition of the blue pigment copper phthalocyanine blue (B 15:3),
pyrolysis - GC/MS was used among othertechniques.

© iStock / EricFalco

Pyrolysis GC/MS shines a lighton laser induced breakdown
fragments

8

To pyrolyze the B 15:3 pigment, thescientists relied on a Thermal Desorption Unit (TDU), equipped witha pyrolysis module (PYRO), bothfrom GERSTEL. For the online
coupled GC/MS analysis, an instrument setup consisting of a 7890A
GC and a 5975C inert XL Mass
Selective Detector (MSD) wasused, both from Agilent Technologies, Inc., Palo Alto. The pigment
sample was placed inside a quartz
liner, which was automaticallytransferred to the PYRO moduleby the GERSTEL MultiPurpose
Sampler (MPS). The pyrolysis
step took place within a temperature range from 500 to 1,000 °C
lasting 6 sec. A carrier gas flowof 1 mL/min (Helium) transported the pyrolysis fragments
via the Cooled Injection System (CIS) PTV type GC inlet,

which was kept at a temperature of 260 °C, to the
GC column (HP-Plot/Q, 30 m, 0,32 mm x
20 μm ID from Agilent Technologies).
Analyte separation was performed
using a temperature gradient: Initial temperature 50 °C (2 min);
10 °C/min to 260 °C (10 min);
EI ionization; full scan mode
detection 10 to 550 m/z. Pyrolysis fragments were determined using the NIST MS
library (US-NIST, National
Institute of Standards andTechnology, 2011 MS Library).
Fragments found were: 1,2-Benzenedicarbonitrile (BDCN), benzonitrile (BCN), benzene and Hydrocyanic acid (HCN). Schreiver et al.
reported that with increasing pyrolysis
temperature the amount of fragmentation products formed also increased.

Accuracy of the pyrolysis
simulation verified
In order to assess whether pyrolysis of pigment B 15:3 produced thesame fragments as laser radiation
breakdown, the scientists produced
different water based dispersions of
the pigment and subsequently irradiated these with a pulsed ruby laser.
The irradiated samples were thenanalyzed, first by Dynamic Headspace (DHS)-GC/MS to quantify thevolatile compounds HCN and benzene. The previously described MPSDHS-TDU-GC/MS system was used.
D6-benzene was used as internal standard. Secondly, ethyl acetate extractsof the irradiated dispersions were analyzed by two-dimensional GC/Timeof-Flight-MS(Leco-Pegasus
4D
GCxGC-ToF-MS) specifically in orderto quantify BDCN and BCN. This was
successfully achieved using benzyl nitrile
and Benzyl alcohol as internal standards.
In all cases, Schreiver et al. used the GERSTEL MPS for automated sample preparation and introduction.
The DHS-GC/MS determination was
performed by thermostating the samples
in the agitator for three minutes at 30 °C.
Analytes were purged with a 100 mL volume of nitrogen (N2) at a flow rate of 50
mL/min and focused in a sorbent trap
inside a TDU tube (Carbopack B+X/
Carboxen 1000). Analytes were desorbed inside the TDU and re-focusedin the CIS at -50 °C. After 12 sec, the

GERSTEL Solutions worldwide – No. 17

Assessing toxicity
For Ines Schreiver and her colleagues, a key question inthis matter is whether laser induced breakdown of phthalocyanine blue actually generates degradation products inamounts that are unsafe – apart from the fact that hydrocyanic acid and benzene are known to be acutely toxic anda carcinogen, respectively. To find an answer, the scientists
used a special experimental design based on human cells,
which were exposed to sodium cyanide (NaCN) solutionsof different concentrations. DHS-GC/MS was subsequently used to determine the amount of HCN liberated
by the cells in order to get a picture of the kinetics of the
HCN formation and its distribution in adjacent tissue following exposure to laser radiation. The scientists quote theU.S. Centers for Disease Controls and Prevention (CDC)
as source for the fact that the lethal dose of HCN is around2 mg/kg body weight “in most animal species” and thatthe “immediately dangerous to life or health concentration(IDLH) in air is 50 ppm (www.cdc.gov/niosh/idlh/74908.
html). According to Schreiver and her colleagues, investigations with laser treatment of the tattoo pigment phthalocyanine blue have shown that toxicologically relevant
concentrations of HCN are formed and that these have asignificant effect on the ability of the cell to survive. In their
totality, the experiments indicate that during laser treat-

GERSTEL Solutions worldwide – No. 17© iStock / damiangretka
It may be a gentler treatment than previous generations of tattooees
had to endure, but using a laser may entail certain health risks.

ment of light resistant phthalocyanine blue B 15:3 in skin,toxic fragments are formed in amounts that could mostprobably influence both the skin locally and systemicallyother tissue in the organism. Further studies will be neededusing human skin ex vivo to investigate the formation of
HCN and benzene during laser treatment as well as theconsequences of their presence. Further, the scientists suggest that all this information be taken into account and in
future quality assessment and approval processes for tattoo
inks.

Literature[1] Ines Schreiver, Christoph Hutzler, Peter Laux, Hans-Peter Berlien & Andreas Luch, Formation of highly toxic hydrogen cyanide upon ruby laser
irradiation of the tattoo pigment phthalocyanine blue; Scientific Reports 5, Article number: 12915(2015)(www.nature.com/articles/srep12915 , 2017/02/15)© GERSTEL / Wolfram Schroll

CIS was heated to 40 °C (5.5 min) and then heated within
seconds to 240 °C (5 min). The TDU and transfer systemtemperature were then kept constant at 260 °C for the remainder of the run. Sample introduction to the GC column was performed in splitless mode. The GC oven initial
temperature was set to 40 °C (0.5 min) and then ramped at
10 °C/min to 260 °C (10 min). The mass range from 10 to
350 m/z was scanned with parallel Single Ion Monitoring(SIM) of the masses 27, 28, 78, and 84 m/z, each with adwell time of 40 ms.
The GCxGC-TOF-MS determination of fragments
generated during laser treatment was approached as follows: To a 196 μL sample placed in a 2 mL vial, the MPS
added an internal standard and subsequently performed aliquid/liquid extraction with ethyl acetate for one hour inthe agitator. A 1.5 µL aliquot of the resulting extract was
introduced to the GC inlet for two-dimensional separation: The first dimension was based on a Restek Rxi-5Sil
MS column (20 m, 0.25 mm, 0.25 μm ID), the second
on a Restek Rxi-17Sil MS (1 m, 0.18 mm, 0.18 μm ID)
column. The initial oven temperature was set to 70 °C(1 min), followed by a 15 °C/min ramp to 120 °C (0 min),
8 °C/min to 150 °C (0 min) and finally 25 °C/min to
330 °C (4 min). Effluent fractions from the first column
were trapped and subsequently released into the second
column using thermal modulation based on a cryofocusing temperature of -80 °C. For the second dimension
separation, the temperature program was set a few degrees
higher than the first dimension program. The ion source
temperature was set to 250 °C, the transfer line to the MS
to 295 °C. Mass spectra were recorded at a rate of 200 Hz
scanning from 35 to 500 m/z. BCN and BDCN were unequivocally identified and quantified.

GC/MS system similar to the one used at BfR in Berlin:
GERSTEL MPS with TDU 2, PYRO, and DHS mounted
on a GC/MS system from Agilent® Technologies.

9© Jan Garbe-Immel

Drinking Water Analysis

Efficient monitoring of disinfection
byproducts in chlorinateddrinking water
Water is chlorinated to eliminate potentially harmful bacteria. In the process, unwanted disinfection
byproducts (DBPs) are formed such as halogenated acetic acids (HAAs), which could themselves
be harmful, albeit probably to a lesser degree. The US Environmental Protection Agency (EPA)
mandates monitoring of HAAs in water using US EPA method 552.3. The procedure in the method
is very labor intensive, limiting the number of samples analyzed per day to about 8 or 9 for a seasoned laboratory technician. In this article a system is described, which enables much more efficient monitoring of HAAs. In addition, a method is described for monitoring how polymer materials
react with disinfection chemicals.
By Guido Deussing

10

GERSTEL Solutions worldwide – No. 17© GERSTEL / Wolfram Schroll

A comparable GC/MS
system is used by David
Benanou and his colleagues
to determine chemicalcompounds leaching frompolymer based pipes andpipe systems into drinking
water.

T

he use of chlorinated disinfectants inthe production of safe drinking water
is aimed at killing or disabling pathogens
such as harmful bacteria in the water. The
disinfectants of course also react with other dissolved or suspended matter, forming
unwanted disinfection byproducts (DBPs)
in the process. Concentration levels of some of the approximately 600 DBPs identified to date should be monitored
closely since they are suspected of being harmful to humanhealth.

A blessing and a minor curse:
Disinfectants
The list of the most unwanted DBPs includes the usual
suspects such as trihalomethanes (THMs), with chloroform serving as probably the most prominent representative of this class of compounds. Another set of DBPs,
long in the sights of the US Environmental Protection
Agency (EPA), are halogenated acetic acids aka haloacetic
acids (HAAs): monochloroacetic acid; dichloroacetic acid;
trichloroacetic acid; bromoacetic acid; and dibromoacetic
acid. The EPA classifies these compounds and compoundclasses as „probable carcinogens“ [1] and drinking water
has to be monitored for residues. The maximum concentration level (MCL) for total THM (TTHM) in drinking
water in the US is 0.08 mg/L [2], the same as in the European Union (EU). In Germany, the MCL is set to 0.05
mg/L [3]. The EPA specifies a total of 0.06 mg/L of thepreviously mentioned five haloacetic acids (HAA 5) as the
maximum concentration limit.
According to Dalel Benali, Senior Scientist for chromatography and water analysis expert working for the leading French water supplier Veolia in Paris, the European
Union (EU) has been given a recommendation to limit theacceptable total concentration of HAAs in drinking water to 0.08 mg/L. The health risk posed by DBPs may be
extremely limited compared with the risk posed by waterborne microbial contaminants [4], says Mr. Benanou, but
due to their suspected carcinogenic properties, the routine
monitoring of THMs and HAAs in drinking water seemsa reasonable and prudent precaution. Equally, swimming
pool water should be monitored, since urine of adults andchildren alike has shown markedly increased HAA levels
after swimming in chlorinated water, Mrs. Benali adds [5].

GERSTEL Solutions worldwide – No. 17

More efficiency and productivity throughminiaturization and automation
In the point of view of David Benanou and Dalel Benali,
who have both been involved in routine monitoring of
drinking water for many years, the determination of HAAs
in water needs to be automated. The US EPA method552.3 specifies the determination of HAAs in water byliquid-liquid extraction using MTBE, followed by derivatization (methylation) and GC-ECD [6]. According
to Mr. Benanou, this process is too complex and requires
too much organic solvent.
GERSTEL Twister
Even a seasoned technician
can only perform 8-9 analyThe Twister® is used for Stir Bar Sorptive Extraction (SBSE). The Twister is available in differses per day based on manualent versions, sorbent volumes, and two differsample preparation. By minent sorbent phases: The polydimethylsiloxane
iaturizing and automating(PDMS) Twister is well suited for extraction
and concentration of non-polar to medium
the method using a dual rail
polarity compounds from aqueous phase; theversion of the GERSTEL
ethylene glycol (EG) Silicone Twister is mainly
MultiPurpose
Sampler
useful for more polar species, especially thosecapable of forming hydrogen bonds as elec(MPS) for the extraction
tron pair donors such as phenols, alcohols, andand derivatization steps, andacids. In order to increase the overall analysis
by using GC/MS instead ofsensitivity, several quite simple approaches canbe taken: Several Twisters can be desorbed,
GC-ECD, Mr. Benanou
either sequentially (sequential desorption) or
and his scientist colleagues
simultaneously and the combined analytes
succeeded in dramaticallysubsequently focused and introduced to the
GC column for a single GC/MS analysis run. Usimproving both efficiency
ing the GERSTEL Twicester® accessory, multiple
and throughput for the deTwisters can be used simultaneously to extract
termination of THM anda single sample. For example, one Twister canbe placed in the headspace of the vial while
HAA [7].
the other is immersed in and stirs the liquid
Key factors in improvphase. These Twisters can be the same or difing the performance are theferent sorbent types. For more information:
www.gerstel.com
analyte concentration andderivatization steps. HAAs
are present at very low levels, are by nature polar, and are
not easily separated by GC making a derivatization stepnecessary. The standard 552.3 method specifies the following steps: Adjust the sample pH to 0.5. Extract it with
MTBE and derivatize with acidified methanol for twohours at elevated temperature. Separate the phases by add-11

Graphic rendering of the GC/
MS system and MultiPurpose
Sampler (MPS) used by Veolia
in Paris for automated determination of halogenated acetic
acids in water. Key, labor intensive sample preparation steps
specified in the EPA method
were successfully transferred tothe autosampler and sample
preparation robot, including
liquid-liquid extraction and therequired analyte derivatization.
The Dual Rail or Dual Headversions of the MPS enable theuse of syringes with different volumes without time-consuming
syringe changes.

3 x 100 mL
Wash station

10 µL Syringe

1 mL Syringe

Heated trays(Peltier)
AgitatorTrays(2 and 20 mL vials)

ing an aqueous sodium sulfate solution and then neutralize
by adding sodium bicarbonate (NaHCO3) in solution. A
portion of the MTBE phase is finally injected into the GC.

Chlorination furthers the extractionof additives from polymer pipes
When using an autosampler, in this case a GERSTELMultiPurposeSampler (MPS), only a fraction of thetime is needed for sample processing compared with themanual method. In the case of the MPS, the PrepAhead
function even provides overlapping, i.e. parallel sample
processing and GC analysis, helping to further acceleratematters and improve throughput. In practice, the system
can analyze 32 samples per day following the EPA 552.3
method, requiring only 1 hour of technician time for sample loading, preparation and further processing. Anotherbenefit is that much less solvent is consumed saving costand improving the overall work environment in the lab.
Method performance is equally convincing, the limit ofdetermination is 1 ppb; the method was validated for all
determined HAAs showing good linearity up to 50 ppb
and a median repeatability (RSD) of 3.2 % (n=3 at 1 and40 ppb) [7].
In practical use, says Mrs Emilie Cocardon, senior scientist at the Veolia Research Center and member of the

Cl

OH

OH
Br

Cl

Analytical Team, the chlorinated disinfectants react withmore than just the organic and inorganic matter present in
the water: The exposed surfaces of the entire supply system
are made up of numerous different polymer materials usedin pipes, connectors, gaskets, sieves, filters, or membranes,from which additives can leach into the chlorinated water
and/or react with the disinfectant. The experts from Veolia
especially focus their attention on additives such as plasticizers and stabilizers, which are used to optimize polymers
for their intended use: “It is normally very difficult to predict
how a polymer and the additives contained in it react to achlorinated disinfectant”, Mr. Benanou admits, “You reallyneed empirical data”. In order to determine DBPs formed
as a reaction between disinfectants and polymer materials,
scientists developed a special method for Veolia based on the
Stir Bar Sorptive Extraction (SBSE) technique using the
GERSTEL Twister combined with thermal desorptionGC/MS analysis.

Twister: The ideal Tool for water analysis
SBSE is a powerful extraction and concentration technique, well suited for ultra-trace analysis and determination of organic compounds in aqueous samples. The SBSE
technique is very similar to the solid phase micro-extraction (SPME) technique. Both techniques enable the ex-

Br
Br

X

X

HO

OH

OH
Br

SBSE of chlorinated water was used to determine the presence of compounds leached from an experimental polymer pipe material incontact with chlorinated water. Three main compound classes were found: Halogenated phenols such as 2,4,6-trichlorophenol, 2,4,6-dichlorobromophenol, and 2,4,6-Dibromochlorophenol; halogenated alkyl-phenols; as well as various isomers of halogenated bisphenol A.

12© Veolia

OH

Solvent Filling
Station (SFS)GERSTEL Solutions worldwide – No. 17© Veolia / David Benanou / GERSTEL

5 x 10 mL
Wash station

© GERSTEL / Sebastian Widmann

traction of analytes
Twister Tap or ARISTOT
into a polymer sorpSometimes drinking water intermittently
tion phase directly
smells strange, unsettling residents in theirin contact with thehome or workplace. When someone finallyturns up to take a sample for analysis there
sample. The SPME
may not be a noticeable smell, making trousorption phase is a
ble shooting and analysis hard to perform. A
thin layer applied topatented technology is available in the formof an adapter for water faucets that enables
a fiber. SBSE uses
time weighted average (TWA) sampling ofa glass coated magwater. The Twister Tap adapter holds six
netic stir bar known
GERSTEL Twisters which extract odor causing compounds and other contaminants
as the GERSTEL
over a period of up to several days for subTwister, coated withsequent thermal desorption and GC/MSa significantly larger
analysis.
volume of sorbent
phase,
generally
resulting in much higher analyte recovery. Handling theUsing this method, additives, including stabilizers have
Twister is simple; it is designed for routine use, as Emi- been determined in polymer tubing using mineral water as
lie Cocardon and David Benanou explain: “The ana- a test solution. Among the DBPs determined in various
lyte extraction takes place while the Twister actively stirs tested materials are 2,4,6-trichlorophenol, which readily
the sample, a large number of samples can be extracted undergoes microbial transformation to the intensely moldyin parallel using multi-position stir plates. The Twisters smelling 2,4,6-trichloroanisol (TCA) [8]. Veolia scientists© Veolia

Chromatogram of a mineralwater showing leachedchemical compounds
from tested polymer pipematerial. The water was kept
for a specified period of time
inside the pipe and extracted
by liquid extraction and LC/
MS determination. The eluting
compounds were identified
as the polymer additives
Irganox, Irgafos and theirbyproducts.

are removed from the samples, dabbed dry on lint-free
cloth, transferred to sealed glass tubes and placed in thesample tray for automated thermal desorption using the
GERSTEL Thermal Desorption Unit (TDU) or alternatively the Thermal Desorption System (TDS). The Twisters are individually heated in a flow of inert gas and analytes are thermally desorbed and quantitatively transferredto the GC/MS system for determination.”

Experimental setup facilitatesmaterial testing
To determine the identity and concentration levels of compounds that could potentially leach out of polymer pipes
tested for use in water supply systems, Veolia scientists havedeveloped an experimental setup, which is beautiful in its
simplicity: A piece of the water pipe to be analyzed is cut
off and sealed at one end. The sealed piece of polymer pipe
is placed in the upright position on a magnetic stir plate
and an aqueous solution containing the disinfectant is added for a specified period of time. The solution is stirred andextracted using a Twister, and any DBPs formed and extracted are subsequently determined by TD-GC/MS. The
Twister is used as described above, without the use of toxic
solvents, which could dilute the extract and mask peaks ofinterest in the chromatogram.

GERSTEL Solutions worldwide – No. 17

in Paris are routinely using SBSE to test polymer materials
before they are accepted for use in the immense drinking
water supply systems of Veolia, just in France. The main
beneficiary in the end is the consumer, who can be surethat the water that comes out of the tap in his or her home
is clean, safe to drink, and free from unpleasant odors.

Literature[1] Controlling Disinfection By-Products and Microbial Contaminants in
Drinking Water, US EPA, www.epa.gov/sites/production/files/2015-09/
documents/dwstandards2012.pdf[2] National Primary Drinking Water Regulations, www.epa.gov/your-drinking-water/table-regulated-drinking-water-contaminants[3] https://en.wikipedia.org/wiki/Trihalomethane[4] Disinfections and Disinfection By-Products, www.who.int/water_sanitation_health/dwq/S04.pdf and www.who.int/water_sanitation_health/dwq/fulltext.pdf[5] M. J. Cardador, M. Gallego, Haloacetic Acids in Swimming Pools: Swimmer and Worker Exposure. Environ. Sci. Technol. 45 (2011) 5783-5790[6] Determination of haloacetic acids and dalapon in drinking water byliquid-liquid micro extraction, derivatization, and gas chromatography
with electron capture detection, https://nepis.epa.gov/Exe/ZyPDF.
cgi/901V0400.PDF?Dockey=901V0400.PDF[7] Poster Presentation, DBP 2014: Efficient Monitoring of Regulated
By-Products using automated, miniaturized, green techniques. David
Benanou and Dalel Benali-Raclot, Veolia Environnement, R&D Centre
for Water, Maisons Laffitte (Paris), France[8] Poster Presentation, DBP 2014: Characterization of emerging Disinfection By-Products from Polymeric Materials by in situ Stir Bar Sorptive
Extraction-GC/MS. David Benanou and Dalel Benali-Raclot, Veolia
Environnement, R&D Centre for Water, Maisons Laffitte (Paris), France

13

Aroma Office 2DMS- and Two-Dimensional Linear Retention
Index Database for identification of flavor
compounds
he retention time of a compound on a given column
phase can be expressed on ascale based on n-alkane retention times. This produces uniqueretention index values for compounds and serves to standardize
gas chromatographic retention
data. Both linear retention indices and programmed-temperature retention indices are widelyused in the flavor and fragrance
field and many published databases are available. Usually mass
spectral information in addition to retention time data isavailable from a GC run, buteither information dimension
alone is often insufficient for
positive identification – even though modern affordable
bench top instrumentation offers highly reproducible
retention behavior and information rich mass spectral
patterns. Aroma Office 2D, exclusively available fromGERSTEL, offers an integrated software approach toautomatically process retention index and mass spectral
data for improved identification of flavor compounds
based on the most comprehensive data base of flavor
compounds commercially available. This is a searchable
data base with retention index information on >10,000

compounds from greater than
100,000 entries from a wide
range of literature references.
The program can be integrated
into the Agilent ChemStation
software and searches are performed using RI values and the
CAS No. of a candidate compound. After library searching, a manual cross search fora single or limited number ofcompounds can be performed
or an automated cross search
can be performed for multiple
compounds. Both use a single
RI and a mass spectrum foreach compound. When thechromatographic analysis is
upgraded to two dimensionalwith heart cutting the software also offers a cross searchusing two different retention index values obtained fromthe orthogonal stationary phases used in the first andsecond dimension analyses. When GC-O organoleptic
evaluation is available from both first and heart cut dimensions these signals can provide complementary RI
values. This is often sufficient to propose an identificationeven if the MS signal is weak or absent. Aroma Office 2D
is designed to offer significant additional identification
strategies to the practicing flavor analyst.
© FFO-Image / Fresh FoodT

A p p N o t e 18 3

Aroma Office 2D in use: Complex Hop Essential Oil
Aroma Office 2D (Gerstel K.K.) is an integrated software
approach for simultaneous processing of both retention
index (RI) and mass spectral (MS) data for rapid and improved identification of flavor compounds. The program
can be integrated into Agilent Chemstation Software andsearches are performed using CAS numbers of candidate compounds after library searching and corresponding
automatically generated RI values. When MS signals are
too weak to be used the software allows two RI values
from orthogonal columns (after GC-O organoleptic evaluation) to be cross searched in the database. This offersa very useful additional identification procedure for flavor compounds. The searchable database comprises >10,000 compounds and offers the practicing analyst full
results oriented software AppNote 183
manipulation
AromaOffice: Application of a Novelof RI and MS
Linear Retention Indices Database todata on flavora Complex Hop Essential Oil, www.
compounds.
gerstel.com/pdf/AppNote-183.pdf

533 candidates (DB-Wax)
392 candidates (DB-5)

7 candidates (Cross search: DB-Wax and DB-5)

RI cross search result (DB-Wax and DB-5).

14

GERSTEL Solutions worldwide – No. 17

Material analysis

Indoor air care
Efficient determination of VOC emissions from Polyurethane foam
A fully automated analysis system based on Dynamic Headspace/Thermal Desorption-GC/MS
enables fast and efficient characterization of VOC emissions from Polyurethane (PU) foams, widelyused indoors and in vehicles.

© istock / lutavia

By Guido Deussing

GERSTEL Solutions worldwide – No. 17

15

P

olyurethane (PU) is widely used for “indoor” applications in office and residential buildings as well as invehicles. PU can be made into very versatile foams, well
suited for use in furniture, as a sealant for windows anddoors, for insulation, in vehicle dashboards and seating,and anywhere else strong and durable foam is required.
Depending on the formulation, PU foams contain numerous volatile organic compounds (VOCs), including
blowing agent, flame retardants, and amine catalysts.
These VOCs can be emitted into indoor air potentiallyposing a health risk. Because of this, it is important toknow just how much of these compounds are present insuch materials, in other words what the emission potential is, and just how much is emitted under standardized
conditions designed to simulate real world use.

method parameter tracking for validation purposes. Manual handling of micro-scale chambers is not the most efficient and reliable way to operate in the hustle and bustle
of modern day laboratories. Automation of sampling parameters and sample collection is the best way to generatemeaningful data on emission profiles. Application experts
from GERSTEL in the US and in Germany put theirheads together to test processes that would satisfy therequirements of the American Society for Testing andMaterials (ASTM) for testing of Spray PU foam (SPF)
materials [1].

Most existing methods used for the determination of
VOCs in PU foams are based on environmental chambers. The chambers are designed to mimic conditions
found in an office, residence or vehicle, but they havesome drawbacks. Certain VOCs go under-reported, oreven disappear due to surface adsorption, also referred
to as “sink effects”. These are predominantly seen in larger, unheated, environmental chambers, which are also
costly, cumbersome, and labor intensive to use. Methods
that rely on much smaller micro-scale emission chambers
have shown promise, but until now these have only been
available as manually operated devices that require manual mounting of sorbent tubes for analyte collection. These
are labor intensive to use and do not offer automated andaccurate flow, temperature, and timing control, let alone

The PU sample is taken using a special cutting tool, which is also used as
sample holder.

“The initial task of the team was to determine theinfluence of various method parameters on VOC emissions with the goal of assessing, which parameters impact method ruggedness”, reports Eike Kleine-Benne,
Ph.D., Scientist and Project Manager in the GERSTELR&D Department. In this context, it was very helpful
for the team to be able to use an automated system thatallowed unattended operation with fast sampling under© GERSTEL© GERSTELThe DHS Large sample containers serve as
micro-scale emission chambers enabling theanalysis of a wide range of samples withoutedge effects.

© GERSTEL

Focusing on PU standard
analysis methods

The DHS Large process from extraction to sample introduction.

16

GERSTEL Solutions worldwide – No. 17© GERSTEL© GERSTEL

controlled and traceable conditions. In order to examine
special cutting/coring tool for
EVENT
the method’s effectiveness for different types of SPF, twotaking PU foam samples, which
Meet the authors and learn
different sample types were analyzed: Open cell PU foam
can subsequently be placed in
more during theand closed cell PU foam. The method parameters were
DHS L containers exposing onlyth Conference on Odour“19chosen to replicate “real-world” conditions of the mateone surface. Such tools allow theand Emissions of Plastic
rials. Key method parameters investigated were the temresearchers to properly simulate
Materials“
perature and air sampling volume as well as GC method
real world conditions with resfrom March 21 to 23 atparameters. As a further critical item, the influence ofpect to VOC emissions from PU
the University of Kassel,
the sample shape and size was investigated. Yunyun Nie,materials.
Germany.
GERSTEL application expert explains: “We wanted tohttp://bit.ly/2jXo89u
miniaturize the whole process as the best starting point toComparing Methods
full automation, which would in turn bring us higher efficiency, less risk
In order to properly assess the results obtained with theof errors and
DHS L system, the scientists analyzed the same samples infull traceability”.
parallel using a standard method from the Association of
The GERSTEL
German Automobile Producers (VDA). Method VDA 278
Dynamic Headis widely used in the automotive industry for the determinaspace(DHS)
tion of VOC and SVOC emissions from materials in consystemwastact with vehicle indoor air. Another aim of the comparative
chosen for thework was to determine the performance potential of bothproject coupled
methods. Yunyun Nie summarizes the key facts: “Basicallywith a Thermal
the VDA method 278 is quite simple to perform: A small
Desorptionsample is placed in a thermal desorption tube and thermally
GC/MS system
extracted at elevated temperature. This means you determine
for determinatithe total emission, or emission potential, for a certain sample
on of the trapweight and for two different compound volatility classes.”ped
analytes.
Eike Kleine-Benne adds: “The question remains, however,
The DHS syswhether this provides results that relate to real world situaThe cutting tool remains in place and surrounds
temoffersautions. Using the DHS L, you can more accurately simulate
the sample throughout the analysis, meaning
tomatedcontrol
the actual emissions from a material since these mainly deemissions escape and can be measured exclusively via the surface that is typically in contact
of a wide range
pend on the surface emission rates of the various compoundswith the surrounding air.
of method paramonitored. This is much closer tometers: Tempereality, but obviously the VDA 278
rature, timing, flow, purge intervals, air volume sampled,
method enables material producers
and type of (sorbent) trap. The version chosen for theto very quickly determine the emisproject was the DHS Large (DHS L) capable of procession potential of a material and tosing samples in containers of up to 1 L in volume. The
make sure that it is suitable for use
DHS L autosampler holds up to 11 samples, which canin a vehicle”.
be processed automatically overnight or on
weekends.
Yunyun Nie: “The DHS Large sample
containers serve as micro-scale emission chambers, enabling us to investigate
many different types of samples – edge
effects are eliminated by using
dedicated sample holders”.
The edge effect is causedby emission of VOCs fromthe “edge” of a material
that has been freshly cut to
fit into a sample chamber.
Such emissions can cause
high readings, since in typical applications VOCs
are emitted only fromthe surface of the foam.
GERSTEL has solved thisGC/MS system used for the determination of VOC emissions from Spray PU foam samples; to the right,
problem by developing a
the DHS Large autosampler.

GERSTEL Solutions worldwide – No. 17

17

As expected, the two methods provided different results [1]. The DHS L-TD-GC/MS system enabled fully automated sampling and determination of compounds
emitted from the SPF sample surface at a temperature
close to ambient temperature. The focus of the DHS L
method parameter selection in this project was mainly on
flow, temperature, and timing while generating an accurate
emission-time profile for SPF with close to zero manualintervention. Such profiles can be highly useful when determining the suitability of a material for indoor use, but
normally requires very time-consuming environmental
chamber work. Experiments to determine material emission behavior under different material installation conditions
were also performed; these were simulated simply by choosing different flow levels.

Comparing Results
As Eike Kleine-Benne reports, blowing agents, amine catalysts, and flame retardants were conclusively determinedin both open cell and closed cell PU foams using the DHS
L at 23 °C, the temperature specified for standard environmental chamber work in most countries. Unsurprisingly,
higher temperatures were found to bring higher emission
rates. A 15-hour monitoring program in the DHS L micro-scale chamber yielded unequivocal results about emission behavior and emission factors of the sample. One interesting observation was how sample thickness influenced
the results. It was determined that thicker samples resulted
in higher emission rates for open cell foams. “This definitely needs to be taken into account in any future standardization work”, says Dr. Kleine-Benne, adding: “For open cell
foam samples, the volume and thereby the internal analytetransfer plays a key role. For closed cell samples, analytetransfer through the surface is the deciding factor”.

NEW

Automation brought key insights
Automation of their analysis has brought tangible benefits, the scientists agree: “The analyst is much less tied tothe instrument and sample handling process, leaving time
for more pressing work such as planning, data handling,
and reporting”. Additionally, the extensive software control provides full documentation and traceability of methodparameters, which in turn helps with future method development and validation. For comparison purposes, direct
thermal extraction in the GERSTEL TDS, as described inthe VDA 278 method, was successfully used for qualitativeevaluation of SPF and other PU foam samples. Using thetwo methods, the same analytes were found to be present,
these were: Bis(2-dimethylaminoethyl) ether (BDMAEE),
Bis(2-dimethylaminoethyl) methylamine (PMDTA),
Bis(dimethylaminopropyl) methylamine (DAPA), Tris(2chloroisopropyl) phosphate (TCPP), Tetramethyliminobis-propylamine (TMIBPA) and N,N,N-Trimethylaminoethylethanolamine (TMAEEA). “The automatedsystem,” says Eike Kleine-Benne, “helped us gain a better
understanding of the emission behavior of Spray Polyurethane Foam (SPF), or rather of the constraints and rate
limiting conditions that influence the emission behavior- and the results. This kind of knowledge is important tohave when you set out to develop standardized methods.”

Literature[1] Yunyun Nie, Eike Kleine-Benne, Kurt Thaxton, Measurement of Chemical Emissions from Spray Polyurethane Foam (SPF) Insulation Using an
Automated Micro-Scale Chamber Coupled Directly with the Analysis
System, Gerstel Application Note No. 188, 2016.
http://www.gerstel.com/pdf/AppNote-188.pdf

Automated
micro-scalechamber
A new fully automated micro-scale chamber analysis system for material emission
testing is available from GERSTEL based onstandard 3.5“ sorbent tubes as specified
in regulated methods. In the DHS L 3.5,
samples are placed in individual inert
chambers with a volume of up to 1 Literat defined temperature and air exchange.
Analytes are automatically collected atuser-defined intervals followed by thermal
desorption in the new TD 3.5+ and GC/
MS determination. Emission profiles canbe established automatically and automated spiking of standards onto sorbent tubes can be performed for calibration andqualification purposes. GERSTEL tubes withup to 25 % more sorbent can be used for
improved analyte recovery, higher breakthrough volume, and lower limits of detection. For more information, please contact
gerstel@gerstel.com.

© GERSTEL

Kasten TD 3.5+ (Bitte Blindtext
setzen für Headline (Vorzeile Productnews) und Lauftext

18

GERSTEL Solutions worldwide – No. 17

Product News

Improving Method VDA 278
Reproducibility through
TDS Temperature Calibration
Thermal desorption instruments are widely used for determination of emissions of volatile organic
compounds from materials. One technique is direct thermal extraction in which a material sample
is placed directly in a thermal desorption tube. An inert gas is supplied under controlled conditionstransferring released compounds from the material sample to a GC/MS system.

T

Deviation (%) from 120 ºC level

TDS in question on site
in the customer laboratory. The procedure is
performed using the
GERSTEL MAESTRO
software feature „VDA
278 calibration“: The
TDS sample temperature
is calibrated by mouseclick at 90 °C and at
120 °C with a resulting
deviation smaller than ±1.0 °C.
This ensures that reproducible results can beobtained from instrument
to instrument and fromlaboratory to laboratory.

Deviation (%) from 90 ºC level

Temperature induced deviation (%) of VOC emission rates from polypropylene pellets compared to the emission rate obtained at 90 °C (marked
grey area represents ± 20 % criteria, two or three runs were performed ateach temperature).

© GERSTEL

Suggested Reading

Temperature induced deviation (%) of FOG emission rates from polypropylene pellets compared to the emission rate obtained at 120 °C (marked
grey area represents ± 20 % criteria, two or three runs were performed ateach temperature).

© GERSTEL / Wolfram Schroll

he widely used VDA
278 method for determination of organic emissions from vehicle interiormaterials is based on direct
thermal extraction. Whenperforming direct thermal
extraction, the desorption
temperature is the mostcritical method parameter,with even small changes
resulting in large variations.
Consequently,
temperature precision should
be tightly controlled andverified.
The recently developed Temperature Calibration Kit for the Thermal Desorption System(GERSTEL TDS 3) ensures that the user will get
the smallest possible desorption tube temperature
variation for the set points
90 °C and 120 °C. The
calibration is performed
through temperature measurements directly in thesample position of the

GERSTEL Application Note
No. 186, 2016 „Improving
Thermal Extraction Method
Reproducibility through Instrument Temperature Calibration in the Sample Position“ www.gerstel.com/
pdf/AppNote-186.pdf

VDA 278
The VDA 278 method describes Thermal Desorption Analysis of Organic
Emissions for the Characterization of
Non-Metallic Materials for Automobiles.
The emissions are classified as VOCs
and SVOCs, determined in two different runs. The SVOCs are described ascondensable substances (FOG value).
To achieve these results, samples areheated and released compounds aretrapped and determined by GC/MS.
In the VDA 278 method, the GERSTEL TDS/TDSA-system is listed as standard system.

GERSTEL Solutions worldwide – No. 17

19© Guido Deussing (7)MPS PrepStation in the LAVES laboratories. Due to its “wing span”, thestaff refers to it as “Condor”. The MPS guarantees uniform results whengenerating standard solutions even when operated by different users.

LAVES: The first and foremost address in the state of Lower Saxony, Germany, for monitoring food safety including pesticide levels in food.

Laboratory on-site: Visiting LAVES in Oldenburg, Germany

On the Wings of the Condor
The State Office for Consumer Protection and Food Safety (LAVES) in Lower Saxony, Germany,came out on top with the best results in a Europe-wide round robin test of pesticide laboratories
for the determination of pesticides residues in cereals. In the words of the President of LAVES, Prof.
Eberhard Haunhorst, Ph.D., this achievement is made possible by highly educated, trained, andexperienced staff. While obviously true, there is more to the story: In addition to know-how andexperience, top notch laboratory performance requires the right laboratory equipment. GERSTEL
Solutions Worldwide magazine visited the LAVES pesticide laboratories where we joined the staff
at work to gain some insight.
By Guido DeussingT

he room has an air of food storage just like you would
experience in a large scale kitchen facility. A whiff ofocean is mixed with a tangy earthy smell. Yesterday it was
fish, today mushrooms are on the menu. These are delivered straight from the farm to the table: Mushrooms, oys-20

ter mushrooms, wood ear / Judas ear, and shiitake in little
black and red baskets are lined up across the large table.
However, the proof of these foods will not be in their eating – they are here to have their pesticide residue levels
determined by a leading European pesticide laboratory.

GERSTEL Solutions worldwide – No. 17

Among the best laboratories forpesticide analysis in the EU
The Lower Saxony State Office for Consumer Protection
and Food Safety (LAVES) has its headquarters in Oldenburg (OL), Germany. Here, the main laboratory is located, part of a network of six laboratories throughout thestate. The mission statement makes it clear: “LAVES – weact for the collective good of both humans and animals”.
Among the bullets in the Mission Statement, may be ahint as to why the laboratories are so successful: “LAVES
is committed to continuously improving its processes andachievements”. Among its guiding principles is to offer fulltransparency and to be beyond reproach, always delivering
the right results. Harmful food must never be allowed toreach the plate of the consumer. The attitude is sensible,
but can it always be ensured? Reality may not always be
as clear-cut even though the law is clear: Consumer safety
must always be put before business interests. LAVES uses
the most modern analytical techniques and equipment tomonitor and test food and feed for compliance, forming a
key pillar in the consumer safety structure of Lower Saxony, a German State with nearly 8 million inhabitants. The
LAVES headquarters are housed in a spacious multi-storied glass covered building and harbors a leading European

Team members: TOF, Casper, Ernie, Bert – every GC/MS System in the
LAVES pesticide lab has been given a nickname.

1995, hunting for dioxin in food and feed for fifteen years
before joining the pesticide laboratory. Four Scientists and
15 Technicians work in the laboratories. “When I started
here, there were only four of us”, she reminisces, relaxing at
her neatly organized desk in an office that shows no signof clutter. Dr. Suckrau spends as much time there as in thelaboratory, going over analysis protocols, reports, and interpreting results as well as generating expert assessments.
“What we generate must be legally flawless and incontrovertible in court”, the scientist says, “we do not work forcompanies or private persons, but solely for the government and public services, our clients are food safety monitoring agencies, counties and towns”. The 3,000 food andfeed samples received annually by LAVES are generally
submitted at the behest of the government.

Food analysis mainly of seasonal produce

GC/TOF-MS for pesticide screening: Thanks to the GERSTEL MPS with
Automated Liner Exchange (ALEX), even series of “dirty“ samples are easy
to analyze.

pesticide laboratory for food and feed analysis. In charge
and responsible for its performance is Iris Suckrau, Ph.D.,a sprightly food chemist who has learned her trade stepby firm step starting with vocational training as a Laboratory Technician followed by a High School Diploma anda Food Chemistry university degree capped with a Ph.D.
Talented, hardworking, and ambitious, Dr. Suckrau hasradiated her infectious positive energy at LAVES since

GERSTEL Solutions worldwide – No. 17

In earlier years, says Iris Suckrau, food inspectors wereasked to each deliver a specific number of food samples
to the laboratory for testing. Some clever inspectors wentstraight to the nearest supermarket produce department
and took samples of every tropical fruit and orange insight, expecting them to be laden with pesticides and likely
to earn the inspector praise. “They of course were able tosubmit their assigned number of samples in no time at all”,
says Iris Suckrau, “but from a consumer safety and testing
stand point it didn’t make much sense. Incidentally, tropicalfruits are much better than their reputation”.
Times have changed, though, random testing is out.
Nowadays, samples are increasingly taken on a risk-assessedbasis with sweeping regional controls in our own area, says
Iris Suckrau: “A key focus is on seasonal produce such as
asparagus and strawberries; we are, so to speak, keeping ourown house in order”.
Whenever Greenpeace publishes new figures that point
to increasing levels of chemical residues in bell peppers, lettuce and similar produce, the workload goes up at LAVES.
Sensitized by the news, food inspectors look a little closer

21

On the same wavelength: Iris Suckrau (left) and GERSTEL have an
ongoing collaboration. The first conversation with Sales Manager for theGerman speaking territories Michael Gröger (right) was about the first
Cooled Injection System (CIS) GC inlet, installed at LAVES in 1997.

during unannounced visits to see if hygiene regulations areadhered to and quality standards met. More samples arethen taken when visiting bakeries, meat producers, foodprocessors, food merchants, cafes, restaurants, and otherlarge kitchen facilities. If the food quality seems lacking,and if even there is the slightest suspicion of a potential
violation of consumer protection laws and food safety
regulations, the inspector must take replicate samples. The
initial sample is sent to LAVES and the replicate sample
is sent to the producer enabling them to request a second
opinion from an independent third party certified laboratory in case LAVES confirms that residue levels are indeed
too high. Since such tests are costly, typically the case firstgoes to court and a lawyer gets involved. “The first thing
the lawyer defending the company found in violation does
is to perform a detailed analysis of whether the sampling
was performed in strict accordance with all protocols”, says
Dr. Suckrau, “and because sampling procedures are both
intricate and highly regulated, we train our inspectors on a
yearly basis”. Many inspectors are trained bakers, cooks, orother food processing professionals that have gone throughextra training as food inspectors. Unless the sampling process is performed correctly Dr. Suckrau and her team cannever successfully do their job.

cessories for comprehensive automated sample preparationand introduction. The introduction techniques range fromliquid injection and Large Volume (liquid) Injection (LVI)
to Headspace and solid phase micro-extraction (SPME).
The QuEChERS extraction method (Quick, Easy, Cheap
Effective, Rugged and Safe), is widely used for pesticide
analysis, and is part of the daily routine in the LAVES
pesticide laboratories. The analyzed QuEChERS extracts
often contain a significant amount of matrix residue. Excess matrix residue deposited in the GC inlet liner can leadto changes in analyte recovery and inaccurate results. In
order to ensure system stability, QuEChERS extracts are
injected using the GERSTEL ALEX option (AutomatedLiner Exchange), replacing the GC inlet liner at user defined intervals, in this case after every 20 injections. Matrix
residue is thereby automatically removed from the analysis system, enabling unattended analysis of large batchesof samples in uninterrupted sequences overnight as well as
on weekends and holidays. Thanks to ALEX, strawberry
extracts and other complex matrices don’t pose a problem
to system stability.
Dr. Suckrau walks over to the GC Time-of-Flight
Mass Spectrometer (GC/TOF-MS), which is used to run
the first tests on a sample: “Screening with GC/TOF-MS
and LC/TOF-MS delivers important clues as to the presence of analytes of interest to us in the sample”, she explains, “this information then enables us to find the best
way forward in order to determine, for example, the pesticide residue levels as per the EU Regulation 396/2005.“
Analyte quantification is then performed using afour point calibration curve. If Maximum Residue Levels(MRLs) are exceeded, the analyst proceeds in well-defined,
transparent and traceable steps using standard addition:
The pesticides of interest are added to the individual samples in known concentrations. “Speaking of standard addition”, Dr. Suckrau suddenly says, “follow me!“ The scientist
marches towards the window area, takes a sharp right turnat the end of the bench, and stops in front of a GERSTEL

A look behind the scenes at
the Pesticide laboratory
Hissing and clattering fills the room we enter, shieldedfrom direct sunlight by louvers outside the windows. Theinterior of the GC/MS lab offers a certain familiarity toanyone who feels at home in gas chromatography. Neatrows of GC/MS systems are lined up on clean lab benches.
Behind them, cables and gas lines run to the ceiling totheir respective connection points. Exhaust ducts hover
above the instruments. But the important thing for laboratory performance is how the instruments are equipped:
Most of the GC/MS systems have a GERSTEL MPS
mounted on top, outfitted with different options and ac-

22

LAVES has a huge arsenal of standard substances at its disposal. These areused to generate dilution series, for quantification and reference purposes.

GERSTEL Solutions worldwide – No. 17

MPS XL PrepStation in Dual Rail configuration. “Dueto its wingspan, we call this MPS stand-alone WorkStation the Condor”, explains Katja Kruse, a co-worker of Dr.
Suckrau, “it holds a large number of standards and solutions in refrigerated trays for extended storage stability”.
“The PrepStation“, Dr. Suckrau explains, “is extremely
important to us“. European Union (EU) regulations formethod validation and quality control in pesticide analysis require us to validate our results. To this end, LAVES
stocks an arsenal of hundreds of reference standards, which
can be used to generate standard solutions, mixtures, andassociated dilution series. “As has clearly been established”,
the scientist continues, “the standard addition technique isthe best possible method when it comes to confirming andvalidating analysis results exceeding the specified MRLs.
And this applies to both GC/MS and LC/MS”. Before“Condor” was given its well-deserved place in the lab, a lotof time was spent on preparing standard solutions, but thequality of these standards was not always sufficient to obtain final results of the highest quality. “Using the MPS
PrepStation, we not only work more efficiently, we reliably

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0,12

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0,08

0,08

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generate accurate and highly reproducible results”, says Iris
Suckrau, “and that is extremely important, especially for a
public agency that needs to deliver irreproachable evidence
for court cases to help enforce consumer safety standards”.

Laboratory robots are only human...

0,04

0,04

-40

For improved quality and productivity leading laboratories like LAVES
produce validated standards and automate their sample preparation using
the GERSTEL MultiPurpose Samper (MPS). Pictured Katja Kruse (left) and
Iris Suckrau.

0

20

40

80

Manual Standard Addition

-40

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0

20

40

80

Standard Addition using the MPS

Automating the standard addition process helps on two fronts: Efficiency and performance. Shown to the left: The reproducibility resulting from manually generated standard addition, using pipette and dispenser. Shown to the right: Improved reproducibility
resulting from automated standard addition using the GERSTEL MPS.
Source: LAVES, Oldenburg, Germany.

Incidentally, all GC/MS systems in the room
have been given nicknames: They are called
Casper, Ernie and Bert, and it seems not onlyout of deference to “Sesame Street”: “By giving individual systems clearly recognizable
names, it becomes easier to keep an eye on
both the instrument and the task assigned
to it”, according to Dr. Suckrau. Maybe wehumans have a propensity for assigning personal traits and identities to robots and machines, as assistants and friends.

Automating the Accurate Transfer of Highly Volatile to Highly
Viscous Liquids using a Bench-top
Workstation www.gerstel.com/
pdf/AppNote-187.pdf

GERSTEL Solutions worldwide – No. 17© GERSTEL

AppNote 187

Highly accurate standard
addition and generationof standards and dilution
series can significantly improve the quality of analysis
results. Several useful tools
and techniques are presented and evaluated, including
thermostating;weighing;
Accurate Add function forimproved sampler precision; and vial venting to eliminate vial pressure build-up.

Example:ALEX-GC-MS/
MS-System
for QuEChERS,
Metabolomics,
and Liquid
Sample Prep

A p p N o t e 187

Accurate Transfer of Liquids for highest precisionusing a bench-top Workstation and Accurate Add

23

Preview – coming up in the next issue

www.gerstel.com

Climate change
impacts tea quality© iStock / lzf

Extreme weather with alternating drought
and heavy rainfalls can have negative impact on both yield and quality of crops
such as tea. These are the conclusions
reached by US scientists who have beenassessing seasonal tea crops from monsoon areas in China. Multidimensional
chromatography and a special data analysis software were important contributors
to the success of the project.

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
US and Canada: www.gerstelus.com

Priority Pollutant
DDT in sediment
If you are asked to deliver a statement
as to the degree of pollution in ocean
sediment and to assess the danger toaquatic wildlife, the bio-availability ofpriority pollutants stored in the sediment will probably need to the investigated. The US scientists Robert P. Eganhouse and Erica L. DiFilippo developed
a method based on thermal desorption
GC/MS, with which this task could be
performed in a “simple, cost-efficientand precise manner”.

Innovative solution
for metabolomics© iStock / luchschen

When large sets of blood-, plasma-, or urine samples must be analyzed within an
acceptable period of time, under constantconditions, and with reliable reproducible
results, manual sample preparation may
not be the most sensible approach to thetask at hand. Metabolomics studies generally require an automated approach. Laura Yung Wang et al. developed a rugged,
fully automated method for the determination of phospholipid fatty acids in human plasma for metabolic phenotyping.

Published by
GERSTEL GmbH & Co. KG
Eberhard-Gerstel-Platz 145473 Mülheim an der Ruhr, Germany
Edited by
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
Translation and editing
Kaj Petersen
kaj_petersen@gerstel.com
DesignPaura Design, Hagen, Germany
www.paura.de

ISSN 1619-0076© iStock / robas

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