BACKGROUND Propylene chlorohydrins (PCH) are formed as byproducts in the reaction between starch and propylene oxide (PO). For hydroxypropylated starch (HP-starch) applications in food, JECFA set the maximum allowed total… Click to show full abstract
BACKGROUND Propylene chlorohydrins (PCH) are formed as byproducts in the reaction between starch and propylene oxide (PO). For hydroxypropylated starch (HP-starch) applications in food, JECFA set the maximum allowed total propylene chlorohydrin (PHC-t) residues level at 1 mg/kg. OBJECTIVE To develop an improved analytical method for the determination of the PCH-t content in starches in the low mg/kg range to replace the outdated JECFA method. METHOD A new GC-MS method that utilizes aqueous methanol as extraction medium for PCH. The GC-MS system is equipped with a programmable temperature vaporization injector and Stabilwax-DA column using helium as carrier gas. The quantitative detection is achieved in the selected ion monitoring mode. RESULTS This single laboratory validation (SLV) study showed good linear calibrations for both 1-chloro-2-propanol (PCH-1) and 2-chloro-1-propanol (PCH-2) in the concentration range of 0.5-4 mg/kg in dry starch. The lower limit of quantitation of PCH-1 and PCH-2 was 0.2-0.3 mg/kg in dry starch, the relative standard deviation reproducibility (RSDR) at the concentration level of 1-2 mg/kg in dry starch was 3-5%, and the recovery values for both PCH-1 and PCH-2 were in the range of 78-112% at a concentration level of about 0.6 mg/kg in dry starch.Compared with the current, outdated JECFA method, the new GC-MS method is more sustainable, less laborious and therefore more economical. The analytical capacity of the new method is 4-5 times higher than the analytical capacity of the old JECFA method. CONCLUSION The GC-MS method is fit for a Multi Laboratory Trial (MLT). HIGHLIGHT Based on the results of this SLV and the MLT (will be published in a second paper), the Joint FAO/WHO Expert Committee on Food Additives has recently decided to replace the outdated GC-FID JECFA method for the new GC-MS method for the determination of PCH-t content in starches.
               
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