Yoshimura S.,Yokohama Customs Laboratory |
Akasaki T.,Central Customs Laboratory |
Ishikawa T.,Yokohama Customs Laboratory |
Ofuji M.,Yokohama Customs Laboratory |
And 3 more authors.
International Sugar Journal | Year: 2014
Increased environmental and health concern about lead compounds is making it difficult to purchase basic lead acetate and will not therefore allow analysts to use the current ICUMSA method GS1/2/3-1 for much longer. In order to seek an environment-friendly alternative, we compared the existing method with a possible replacement which is lead-free, including the transition to a tentative ICUMSA method GS1/2/3-2 (Near Infra-Red polarimetirc method). Sixteen non-lead chemical compounds and one lead-free deproteinizing agent (a combination of a zinc sulfate solution and a barium hydroxide solution) were tested for clarifying raw cane sugars from Australia, Thailand and Philippine for polarization analysis. Findings indicated that a combined pre-treatment with a lead-free deproteinizing agent followed by a celite filtration was effective for clarifying raw sugars. The polarization values analyzed using the lead-free pre-treatment method were nearly equal to those by the ICUMSA method GS1/2/3-1 (the difference: ±0.04 (AVE ±0.00); n=11) with no statistical significance at the 95% confidence level. The robustness (%RSD < 0.01; r ≤ 0.10) of the lead-free polarization analysis method was evaluated by a repeatability test with five duplicates of five different samples. Therefore, the pre-treatment method developed in this study is effective to replace the current ICUMSA method GS1/2/3-1 to its lead-free version with a minor modification but without diminishing the accepted robustness for an ICUMSA official method. To validate this method further, it is proposed that the method be tested on raw sugars from other parts of the world including those with a relatively high average polarization value.