In this work,a field-applicable,simple method for quick detecting chlorogenic acid(CGA)was developed.The method is based on CGA’s antioxidant property.CGA is reported to reduce a mixture solution of FeCl_(3)/K_(3)Fe(...In this work,a field-applicable,simple method for quick detecting chlorogenic acid(CGA)was developed.The method is based on CGA’s antioxidant property.CGA is reported to reduce a mixture solution of FeCl_(3)/K_(3)Fe(CN)_(6)to generate Fe_(4)[Fe(CN)_(6)]_(3),the Prussian blue,in an aqueous solution.This reaction was adopted in this work by using solid-ink printed annuli on a filter-paper as reaction vessels.The reagent is pre-loaded and dried within the solid ink printed circles.In a field test,a drop of a sample solution is directly applied to a reagent-loaded circle.The reaction product within the circle shows a blue color,which is detected by using an iPad(or cellphone)camera as a detector and a light-emitting diode flashlight lamp as a light source.A freely available RGB colorimeter program from Apple store was used to read light intensity of three colors:red,green,blue,and absorbance signal of red and blue light is calculated.The difference of absorbance signal of red light from that of blue light was found having linear relationship with CGA concentration in an aqueous sample solution.This simple method is sensitive with a detection limit of 1.0μg/mL for CGA in sample solution.The technique was used to analyze CGA concentration in green coffee extract,and the analytical results agree well with that obtained using a UV/Vis absorption spectrometric method.The real sample test results demonstrate the usefulness of this simple method for quick detecting CGA in green coffee extract products in field test applications.展开更多
基金Killgore Research Grant Program of West Texas A&M University for providing fund to purchase the solid ink printer used in this work
文摘In this work,a field-applicable,simple method for quick detecting chlorogenic acid(CGA)was developed.The method is based on CGA’s antioxidant property.CGA is reported to reduce a mixture solution of FeCl_(3)/K_(3)Fe(CN)_(6)to generate Fe_(4)[Fe(CN)_(6)]_(3),the Prussian blue,in an aqueous solution.This reaction was adopted in this work by using solid-ink printed annuli on a filter-paper as reaction vessels.The reagent is pre-loaded and dried within the solid ink printed circles.In a field test,a drop of a sample solution is directly applied to a reagent-loaded circle.The reaction product within the circle shows a blue color,which is detected by using an iPad(or cellphone)camera as a detector and a light-emitting diode flashlight lamp as a light source.A freely available RGB colorimeter program from Apple store was used to read light intensity of three colors:red,green,blue,and absorbance signal of red and blue light is calculated.The difference of absorbance signal of red light from that of blue light was found having linear relationship with CGA concentration in an aqueous sample solution.This simple method is sensitive with a detection limit of 1.0μg/mL for CGA in sample solution.The technique was used to analyze CGA concentration in green coffee extract,and the analytical results agree well with that obtained using a UV/Vis absorption spectrometric method.The real sample test results demonstrate the usefulness of this simple method for quick detecting CGA in green coffee extract products in field test applications.
