MBTH for aliphatic aldehyde measurement

Abstract

A new method is proposed where a limited amount of MBTH is used to detect a point of interest (POI) of an aldehyde in a test sample. Preferably, it reacts with aldehyde first to form an azine. Only if there is remaining MBTH, it is oxidized to another species which combines with the azine to form formazan. However, if there is enough aldehyde, all the MBTH is converted to azine and there is no formation of blue color. Thus, by using the limiting agent MBTH to test the amount of aldehyde around the point of interest, then less aldehyde would produce more blue color and more aldehyde would produce less blue color. This method is especially useful in the quality control of aldehyde products. The end color may be different depending upon the order of addition of the reactants. For example, if an oxidizing agent and MBTH are mixed before adding the aldehyde, a light green to green/blue color results. This method could be used for solution test or for tests on a solid phase such as on nylon membrane. The latter also could be used for measurements with a device or instrument such as a color reader and used in combination with a second aldehyde tester and a pH tester.

1 - 13 . (canceled)  
   
   
       14 . A liquid measuring device comprising at least one compartment for determining the presence of a point of interest of an aldehyde in a test sample comprising a first compartment having a proximal and distal end which contains an amount of MBTH that reacts with a aldehyde in a first reacting step, wherein said amount is sufficient to react with the aldehyde to the point of interest.  
   
   
       15 . The liquid measuring device of  claim 14 , wherein said first compartment further comprises an oxidant that reacts with the MBTH.  
   
   
       16 . The liquid measuring device of  claim 14  further comprising a second compartment in liquid communication with said first compartment by means of a valve.  
   
   
       17 . The liquid measuring device of  claim 16 , wherein said second compartment contains an oxidant that reacts with the MBTH.  
   
   
       18 . The liquid measuring device of  claim 14  which is a syringe or pipet.  
   
   
       19 . The liquid measuring device of  claim 14  further comprising a gas or vapor permeable but liquid impermeable membrane between the proximal and distal end of the first compartment.  
   
   
       20 . The liquid measuring device of  claim 14  further comprising a filter at or near the distal end of the first compartment.  
   
   
       21 . The liquid measuring device of  claim 14  further comprising a valve at or near the distal end of the first compartment.  
   
   
       22 . The liquid measuring device of  claim 14  further comprising a needle assembly.  
   
   
       23 . The liquid measuring device of  claim 14 , wherein the aldehyde is selected from the group consisting of glutaraldehyde and formaldehyde.  
   
   
       24 . A test strip comprising at least one absorbent material for determining the presence of a point of interest of an aldehyde in a test sample comprising a first absorbent material which contains an amount of MBTH that reacts with an aldehyde in a first reacting step, wherein said amount is sufficient to react with the aldehyde to the point of interest.  
   
   
       25 . The test strip of  claim 24 , wherein said first absorbent material further comprises an oxidant that reacts with the MBTH.  
   
   
       26 . The test strip of  claim 24  further comprising a second absorbent material containing an oxidant that reacts with the MBTH.  
   
   
       27 . The test strip of  claim 26 , wherein said second absorbent material is separated from said first absorbent material with a separator.  
   
   
       28 . The test strip of  claim 27 , wherein said separator comprises a removable liquid impermeable film or a blank absorbent material.  
   
   
       29 . The test strip of  claim 24  further comprising an aldehyde tester.  
   
   
       30 . The test strip of  claim 29 , wherein the aldehyde tester is a Shiff's reagent.  
   
   
       31 . The test strip of  claim 24  further comprising a pH tester.  
   
   
       32 . The test strip of  claim 31 , wherein the pH tester comprises a pH dye indicator selected from the group consisting of bromothymol blue, brilliant yellow, neutral red, rosolic acid, phenol red, 3-nitrophenol, orange II, phenolphthalein, o-cresolphthalein, nile blue A and thymolphthalein.  
   
   
       33 . The test strip of  claim 24  further comprising at least one color comparator.