This application note describes two automated methods for screening of extractable compounds from materials for food packaging, medical or technical purposes. The first method is based on automated liquid extraction performed by the GERSTEL MultiPurpose Sampler (MPS), the second involves thermal desorption of the material in question in the GERSTEL Thermal Desorption Unit (TDU). Both methods are suitable for gaining an overview of the quality and emission potential of a material and therefore useful in the search for a suitable packaging material. The methods deliver comparable qualitative results.

Mineral oil hydrocarbon (MOH) contaminants can be found in foods such as cereals, baked goods, fats and oils, coffee and many more. MOH can be introduced through process aids, additives, and machine- and lubricating oils used during food processing. Packaging such as jute bags used to store and transport foods, recycled cardboard, and printing inks are other major sources of MOH contamination. MOH are separated into Mineral Oil Saturated Hydrocarbons (MOSH) and Mineral Oil Aromatic Hydrocarbons (MOAH). Some MOAH are known carcinogens and MOSH are known to accumulate in human body tissue. Subsequently, food products should be analyzed and monitored for their presence.

A multi-residue method to determine five groups of 85 pesticides - chlorinated, carbamate, phosphorous, pyrethroid and others - in vegetables, fruits and green tea has been developed using stir bar sorptive extraction (SBSE) coupled to thermal desorption and retention time locked (RTL) GC-MS. Pre-extraction with methanol and dilution with water prior to SBSE (60 min) were performed. Dilution of methanol extract for SBSE was examined to obtain high sensitivity and to compensate the effect of adsorption to the glass wall of extraction vessel and to sample matrix for the compounds with high log Ko/w values (e.g. pyrethroid).

A multi-residue method for determination of five groups of 85 pesticides - organochlorine, carbamate, organophosphorous, pyrethroid and others - in non-fatty food, e.g. vegetables, fruits and green tea is described. The method is based on stir bar sorptive extraction (SBSE) coupled to thermal desorption (TD) and retention time locked (RTL) GC-MS in the scan mode. Samples are extracted with methanol and diluted with water prior to SBSE. Dilution of the methanol extract before SBSE was optimized to obtain high sensitivity, and to minimize sample matrix effects (particularly for the pesticides with high log Ko/w values).

Solid Phase Extraction (SPE) using standard cartridges is widely regarded as the method of choice to extract analytes from samples with complex matrices or to extract and concentrate analytes from a wide variety of samples in general. In this paper, an automated SPE system is presented that is based on standard cartridges. It is shown that SPE with standard cartridges is easily and efficiently automated for use in LC/MS-based determination of illegal antibiotics in food products of animal origin. An established manual SPE method was easily transferred to the GERSTEL MultiPurpose Sampler (MPS) using the SPE option under MAESTRO software control.

Malachite green (MG) is a triphenyl methane dye that is highly efficient in battling fungi, bacteria and various single cell parasites. MG is traditionally used in aquaculture to treat and prevent fungal infections. MG, which is structurally related to known carcinogenic triphenylmethane dyes, is metabolized to leucomalachite green (LMG) and deposited in the fatty tissue of the fish. MG is under suspicion of being a human carcinogen and for causing damage to the human genetic material. Consumption of fish that is contaminated with MG is assumed to pose a significant health risk to humans.

Fruit and vegetable extracts that are produced following the well established QuEChERS method [1,2] typically contain a significant amount of involatile matrix material. After several injections of such extracts into the GC, sufficient matrix residue will be present in the GC inlet liner to lower or sometimes even increase the response of certain pesticide compounds affecting the accuracy of the analysis. The performance can be restored by exchanging the GC inlet liner. Normally this has to be done manually which means stopping the analysis sequence.

One of the most important aspects of reducing pesticide exposure is monitoring of pesticide residues in foods. A number of analytical methods have been developed, many of them based on traditional liquid-liquid extraction in combination with GC-MS or LC-MS. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation methods have been developed to help monitor pesticides in a range of food samples [1]. The dispersive Solid Phase Extraction (SPE) used to clean up these extracts can leave co-extractants, which can result in interferences such as ion suppression with the analytical results.

This application note describes two automated methods for screening of extractable compounds from materials for food packaging, medical or technical purposes. The first method is based on automated liquid extraction performed by the GERSTEL MultiPurpose Sampler (MPS), the second involves thermal desorption of the material in question in the GERSTEL Thermal Desorption Unit (TDU). Both methods are suitable for gaining an overview of the quality and emission potential of a material and therefore useful in the search for a suitable packaging material. The methods deliver comparable qualitative results.

The US Consumer Product Safety Commission’s (CPSC) Test Method CPSC-CH-C1001-09.3 [1], is used by testing laboratories for the determination of phthalate content in children’s toys and child care articles covered by the standard set forth in the Consumer Product Safety Improvement Act Section 108. The CPSC determined that an appropriate combination of methods of extraction and analysis is sufficient to determine the concentration of the six regulated phthalates in most consumer products.