This paper describes for the first time a micromethod for the simultaneous determination of 3-monochloropropane-1,2-diol (3-MCPD) and fatty acid esters of 3-MCPD (3-MCPD esters) in different foodstuffs. 3-MCPD and 3-MCPD esters were isolated from food products using a single extraction step separating hydrophilic and lipophilic compounds. An aliquot of the aqueous layer was analyzed for the content of 3-MCPD while a part of the organic layer was analyzed for 3-MCPD esters after cleavage with sodium methoxide. After a simple derivatization procedure with phenylboronic acid (PBA), the determination was achieved by isotope dilution GC-MS using isotope-labeled 3-MCPD and 3-MCPD ester as internal standards. The method was validated for various foodstuffs like bakery products, meat and fish products, and soups as well as seasonings with LOD of 1-2 microg/kg (3-MCPD) and 6 microg/kg (3-MCPD esters), respectively. Recoveries ranged within 95 +/- 9% and 96 +/- 10% at spiking levels of 15 and 25 microg/kg in all matrices for 3-MCPD and 84 +/- 9% and 85 +/- 7% at spiking levels of 0.05 mg/kg and 2 mg/kg for 3-MCPD esters. The method avoids tedious and laborious sample preparation and was successfully applied to the rapid screening of samples conforming to the EU performance criteria for methods of analysis for 3-MCPD.

For the determination of glyphosate, aminomethylphosphonic acid and glufosinate in drinking water, different procedures of enrichment and cleanup were examined using anion exchange or SPE. In many cases interactions of, e.g. alkaline earth metal ions especially calcium could be observed during enrichment and cleanup resulting in loss of analytes. For that reason, a novel cleanup and enrichment procedure for the determination of these phosphonic acid herbicides has been developed in drinking water using cation-exchange resin. In summary, the cleanup procedure with cation-exchange resin developed in this study avoids interactions as described above and is applicable to calcium-rich drinking water samples. After derivatization with 9-fluorenylmethylchloroformate followed by LC with fluorescence detection, LOD of 12, 14 and 12 ng/L and mean recoveries from real-world drinking water samples of 98+/-9, 100+/-16 and 101+/-11% were obtained for glyphosate, aminomethylphosphonic acid and glufosinate, respectively. The low LODs and the high precision permit the analysis of these phosphonic acid herbicides according to the guidelines of the European Commission.

A rapid and simple method for the determination of polyhexamethylene biguanide (polyhexanide, PHMB) in liquid and gel-like pharmaceutical formulations by means of high performance liquid chromatography coupled to diode-array detection (HPLC–DAD) was developed. Best separation was achieved using a cyanopropyl bonded phase (Agilent Zorbax Eclipse XDB-CN column 4.6 mm×75 mm with particle size of 3.5 μm) as well as gradient elution consisting of acetonitrile/deionized water at a flow rate of 1.0 mL/min. The optimized and applied chromatographic conditions permitted separation of polyhexanide from interacting matrix with subsequent detection at a wavelength of 235 nm with good sensitivity. The method validation was carried out with regard to the guidelines for analytical procedures demanded by the International Conference on Harmonisation (ICH). Mean recoveries of 102% and 101% for gel-like as well as liquid preparations were obtained. Suitable repeatability as well as intermediate precision could be achieved with limits of detection ≤0.004 mg/mL for both formulations, equivalent to ≤0.004% PHMB concerning sample preparation. Determination of PHMB was accomplished without tedious sample preparation. Interacting matrix could be eliminated by the chromatographic procedure with excellent performance of system suitability. All analytical requirements were fulfilled permitting a reliable and precise determination of PHMB in pharmaceuticals. Furthermore, the developed method was applied to stability testing of pharmaceutical preparations containing PHMB.

The aim of this study was the development of a method for the simultaneous determination and differentiation of fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD esters) and glycidol (glycidyl esters) in different foodstuffs. The esters were isolated from fat-rich food samples using a single extraction step and separated from interfering substances. For differentiation of 3-MCPD esters and glycidyl esters the glycidol moiety was converted into 3-methoxypropane-1,2-diol (3-MPD) by acidic alcoholysis. Subsequent determination was achieved by isotope dilution GC-MS after transesterification using an isotope-labeled 3-MCPD ester as internal standard. During optimization of the procedure, critical parameters affecting simultaneous determination and differentiation of these analytes were investigated. Rapid ester cleavage and derivatization at ambient temperature proved to be essential for the simultaneous determination of these analytes. The method was validated for various fat-rich foodstuffs such as bakery products, sweets, gravy, and soup powders as well as edible fats and oils. LODs of 8 and 15 μg/kg (fat-rich foodstuffs) as well as 50 and 65 μg/kg (edible oils and fats) were obtained for 3-MCPD esters and glycidyl esters, respectively. Recoveries for 3-MCPD esters and glycidyl esters ranged within 98 ± 4 and 88 ± 2% in all tested foodstuffs (0.05-2.5 mg/kg) and within 99 ± 16 and 93 ± 13% for edible oils and fats (0.15-3 mg/kg) over a wide concentration range. These results proved an accurate and differentiated determination of 3-MCPD esters and glycidyl esters with successful application to the fast screening of samples, avoiding tedious and laborious sample preparation.

A liquid chromatographic method (LC) with diode array detection (DAD) for the routine screening and quantification of highly applicated polar herbicides in drinking water samples was developed. The investigated herbicides consisted of 12 sulfonylurea herbicides (amidosulfuron, flazasulfuron, foramsulfuron, iodosulfuron-methyl Na, mesosulfuron-methyl, metsulfuron-methyl, nicosulfuron, prosulfuron, thifensulfuron-methyl, triasulfuron and tritosulfuron) together with 6 polar pesticides of relevance (atrazine, desethylatrazine, desisopropylatrazine, chlortoluron, diuron, fluoxypyr). The herbicides were extracted and concentrated by off-line solid-phase extraction and subsequently eluates were analyzed by LC-DAD. Recoveries obtained from fortified water samples at 100 ng L -1 were in the range of 84-107% with RSD's \20%. The limit of detection varied from 2 to 16 ng L -1 .