Automated analysis of PAH in foodstuff by LC-LC-GC-MS/MS coupling and the imPAHct method

CHRONECT Workstation PAH and imPAHct -NEW


Automated analysis of PAH in foodstuff by LC-LC-GC-MS/MS coupling and the imPAHct method

The CHRONECT Workstation PAH and the newly developed imPAHct method (innovative multidimensional PAH clean-up technology) by Axel Semrau® provide a high level of automation.

Application Sheet

System Description

Polycyclic aromatic hydrocarbons (PAHs) are formed during partial combustion and pyrolysis processes. They enter the environment through fumes, bound to dust particles or mineral oil residues. PAHs contaminate foodstuff either from the environment (e.g. dust particles on broad-leaf vegetables) or by roasting and smoking processes.

Laboratories analyze PAHs regularly. The reason for this is the partly very high carcinogenicity of the substance group and their broad distribution. European guidelines set limiting values which vary depending on the foodstuff. For the marker substance benzo[a]pyrene the value lies between 1-6 μg/kg while the total limit value for the PAH4 (this term summarizes benzo[a]pyrene, benzo[a]anthracene, chrysene and benzo[b]fluoranthene) is 1-35 μg/kg. The analysis of polycyclic aromatic hydrocarbons (PAH) is a great analytical challenge, due to the variety of food matrices and the detection limits demanded by the European Food Safety Authority (EFSA).

Due to the required sensitivity and complex matrices, PAH determination is a great challenge for analytics. As an analytical method either HPLC with fluorescence detection or GC-MS are used. Sample preparation is often extensive and time-consuming. Conventional analysis methods are using HPLC with fluorescence detection or GC-MS. In both cases, the sample preparation is often extremely extensive and complex. Recent requirements to laboratories include a reduction in sample handling time (Turn-Around-Time) and an increase in the sample throughput. Still, no losses within the analytical parameters, e. g. sensitivity, precision and accuracy are desired. Consequently, highly automated analytical procedures are necessary.

The CHRONECT LC-GC technology by Axel Semrau® has been established for many years in the routine analysis of foodstuff. It forms the ideal base for the solution presented here. The analytics of PAHs is done by a LC-LC-GC-MS/MS system and with the imPAHct method. To measure PAHs, a simple yet fast extraction of the sample is performed. The extract is quickly manually treated and then transferred to the CHRONECT Workstation PAH. Here, the extract is purified by a two-step LC separation (LC-LC Clean-Up) and subsequently analyzed via GC-MS. Edible oils may be measured straightforwardly.

Applying this intelligent matrix management, it is possible to determine the PAHs which are prescribed by EFSA fully automated. Depending on the detector, detection limits are reached which are even lower than the required European values for infant formula by a factor of 100.

The LC-GC solutions by Axel Semrau® are pre-installed and tested in our application laboratory. They are delivered in a ready-for-use condition. The installation includes a Site Acceptance Test as well as a briefing which enables the user to start working with our solution immediately. This ensures the fastest possible start of the routine measuring operation.

Benefits of the CHRONECT Workstation PAH and the imPAHct method

● LOD 1/100 of the limit value for infant formula (example substance benzo[a]pyrene)
● LOD for all EFSA PAH between 0.01 -
0.02 μg/kg with Bruker EVOQ GC-TQ
● LOQ for all EFSA PAH < 0.06 μg/kg with Bruker EVOQ GC-TQ
● repeatability < 10 % for the entire method
● analysis duration: 45 min
● no consumables necessary due to LC-LC Clean-Up
● longer maintenance intervals due to Clean-Up technology
● applicable to cosmetics and all foodstuff
● high sample throughput
● high degree of automation
● investment safety
● universally applicable to all foodstuff

Product Specialist

Dag Dacke

"Our expert in CTC PAL know-how and programming, and more than 20 years experience in the field of chromatography. Contact me if you have questions or need a quotation"

This email address is being protected from spambots. You need JavaScript enabled to view it.
070-7319009

System Components

CHRONECT Robotic consisting of:
● CTC PAL3 with a 85 cm axis
and
Software CHRONOS
● Agilent 1260 Infinity II HPLC pump
with UV detector and degasser
● Bruker EVOQ GC-TQ
● CHRONECT LC-GC Interface for LC-GC coupling
data system with control and evaluation software
accessories and consumables
● Factory Acceptance Test
instruction and commissioning
● Site Acceptance Test
● training and support

LC-LC-GC-MS/MS measurement of cocoa butter which was doted to 0.04 μg/kg with PAH

LC-LC clean-up: first and second purification

Calibration curve for benzo[a]pyrene between 0.04 - 4 μg/kg

Routine-capable LC-GC system for on-line determination of mineral oil contaminations in food, feeding stuffs and packaging.

CHRONECT LC-GC Workstation MOSH/MOAH-NEW


Routine-capable LC-GC system for on-line determination of mineral oil contaminations in food, feeding stuffs and packaging.

This system has been designed for the sensitive and fast detection of mineral oil contaminants in different matrices such as cosmetics, foodstuff, oils and fats, feeding stuff and packagings.

Product Information

Application note

System Description

The method is thoroughly published and tested. In an article in FoodProductionDaily the method was described as the most efficient one: "According to EFSA, the most effective method to detect MOH levels in food is through pre-separation by high performance liquid chromatography (HPLC) online coupled to GC with flame ionisation detection (FID)." (Source).

Product Specialist

Dag Dacke

"Our expert in CTC PAL know-how and programming, and more than 20 years experience in the field of chromatography. Contact me if you have questions or need a quotation"

This email address is being protected from spambots. You need JavaScript enabled to view it.
070-7319009

Special advantages of the LC-GC-System MOSH/MOAH

  • Simultaneous and fast determination of MOSH and MOAH
    This system allows a determination of MOSH and MOAH in 30 minutes only.
  • High level of automation
    Through normal phase HPLC an automated sample preparation and pre-separation is realized. Thereby, MOSH and MOAH fractions are separated from one another and simultaneously from disturbing components like paraffin or wax esters. Standard sample preparation steps as solid phase extraction or manual purification are no longer required.
  • Sensitive determination
  • High level of reproducibility and accuracy
    Great measuring accuracy, similar to a normal split/splitless injection; method validated.
  • Routine-capable methods
    A proper connection of LC and GC reduces solvent consumption and contamination of the GC system. Additionally, it strongly increases the stability of the system. The sample throughput is therefore increased and facilitated by the control through the user-friendly CHRONOS software.
  • GCxGC-Functionality for better determination of MOSH, MOAH and POSH
    Two GC columns with different polarities are applied. An upgrade for the CHRONECT LC-GC Interface is necessary, but can be added easily.
  • NEW: Automated epoxidation as add-on for the LC-GC MOSH/MOAH application
    A solvent change is no longer required due to the modification of the reaction conditions for epoxidation. Additionally, a better recovery of internal standards is given. Epoxidation can be automated within the LC-GC application system and can be done during the runtime of other samples. Another option is the Epoxidation Workbench consisting of a PAL3 RTC/RSI by CTC Analytics. Thus, a high number of samples can be processed offline.

Technical setup of the device

The MOSH/MOAH-System consists of a binary HPLC system, a GC including two FIDs, an evaluation software, CHRONECT Robotic constisting of a PAL3 Autosampler by CTC Analytics and the software platform CHRONOS by Axel Semrau. The key to success are following technical details:

  • Intelligent valve connection: Holds back the MOSH fraction eluted first without losses until the MOAH fraction enters the GC. Then, sample injection to the GC is performed.
  • Large-volume injection: The injection into the GC is performed by independent large-volume injection systems. Injection volumes up to 450 µL can be processed smoothly.
  • 2-Channel-GC: Two parallel and orthogonal chromatographic separations with subsequent FID detections are performed. Consequently, the results concerning MOSH and MOAH contents in a sample are readily available after 30 minutes only.
  • CHRONOS software: The software platform CHRONOS controls sampling, LC and GC including the valve connection and thus constitutes a completely automated control of the method and sample preparation.

This requirements for such a system were developed in close collaboration with end users. Using the CHRONECT LC-GC interface by Axel Semrau the usage of various gas chromatographs is possible. Concerning HPLC, the system may be configured either with a HPLC of KNAUER, Agilent or Shimadzu.

Fully automated analysis of sterols for food control analytics

CHRONECT Workstation Sterols -NEW


Fully automated analysis of sterols for food control analytics

A determination of sterols is essential for the control of purity and quality of for example edible oils. According to the ISO 12228 method, the sample first is saponified and then purified by solid phase extraction.

Product Information

System Description

After neutralization and restriction, the obtained analytes are further purified by means of preparative thin-layer chromatography. Next, the manual removal of the fraction from the TLC plate is necessary. Then, the fraction is derivatized and chromatographically analyzed by GC-FID. Due to numerous manual steps during this procedure, the method is highly time-consuming and error-prone.

Axel Semrau® provides a solution for this kind of analysis. It is based on a LC-GC technology which is also used within the MOSH/MOAH system and is in routine use in several laboratories. Saponification of the sample and many further preparative steps are fully automated. For this purpose, a DualPAL (CTC Analytics) is applied. The DualPAL includes two syringes: One syringe is used to meter the required reagents for saponification, the second smaller syringe is used to perform the injection into the HPLC. Subsequently, purification is carried out through HPLC, which is directly connected to the GC-FID detection.

The sterol-containing HPLC fractions are specifically selected and directly transferred to the GC system. Disturbing components are eliminated by this method. By performing LC first, a preparative thin-layer chromatography is not required anymore. Thus, manual steps are limited to the weighing and positioning of the sample within the autosampler. This great level of automation is achieved through the DualPAL concept with two different syringes and the use of LC for purification in the GC.

An extensive validation of this method in customers laboratories was performed. Therefore, numerous samples containing different known concentrations and distributions of sterols were analyzed. The results verified that the presented method is precise and provides reproducible results. Concerning analytical parameters, this method is equally good or even better than the required ISO values.

The entire control of the system is provided through the user-friendly software CHRONOS, which simplifies complex methods.

 

Product Specialist

Dag Dacke

"Our expert in CTC PAL know-how and programming, and more than 20 years experience in the field of chromatography. Contact me if you have questions or need a quotation"

This email address is being protected from spambots. You need JavaScript enabled to view it.
070-7319009

Advantages of LC-GC coupling

  • High sample throughput
  • High level of automation
  • Low risk of contamination
  • Excellent reproducibility
  • Best possible sensitivity
  • Security of investment
  • Expandable to other applications e.g. determination of mineral oil in vegetable oil, determination of the alkyl ester level, determination of PAH
  • Short familiarization phase through installation of the entire method including a training course
  • Qualified support

Components of the system

  • KNAUER Smartline HPLC system
    or Agilent 1260 HPLC with UV detector and degasser or Shimadzu LC 20
  • CTC DualPAL for automated saponification and purification
  • DANI Master GC with FID, alternatively other GCs
  • LC-GC Interface for coupling of HPLC to the GC
  • Data exchange system including control software and data mining
  • Accessories and consumables

The illustrations below show exemplary chromatograms.
The LC-GC coupling provides two chromatograms simultaneously:

Signal of the UV detector from the HPLC
FID signal of the sterols

HPLC chromatogram: Separation of Δ5- and Δ7-sterols, an impossible process using the manual method. After analysis, the HPLC column rewinds and reconditions during the parallel GC run. This ensures the best sample throughput and steady initial conditions.

GC chromatogram from sunflower oil:

GC chromatogram from rapeseed oil:

KOVALENTS PHILOSOPHY

At Kovalent we strive to establish and develop long-term partnerships with our customers. When we use the word “partnership” we mean that Kovalent becomes an integral part of our customers’ projects, where we are expected to fully understand their application needs. We aim to make Kovalent our customers’ first and natural choice, and this ambition permeates our entire organisation from initial contact to finished and delivered product.

CONTACTS:

Kovalent AB
Hulda Lindgrens gata 6A
421 31 VÄSTRA FRÖLUNDA
Sweden
Phone: +46(0)31-709 81 80
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Org.nr: 556417-2194

SKANDINAVISKA GENETEC AB

Genetec is a member of the same family of companies as Kovalent. Both companies share the same set of values and are in many ways integrated with each other. The main difference between the two companies are their products. Kovalent is involved in system solutions including instrumentation and Genetec is mainly working with consumables. The focus of Genetec is chromatography accessories. You are welcome to visit their state of the art web shop: genetec.se