Method for quantification of analytes in a titanium, tin or silcon tetrachloride sample

Abstract

This disclosure relates to a method for detecting at least one analyte in a tetrachloride sample comprising titanium, tin or silicon tetrachloride; comprising, (a) adding a mixture of water and acid, typically hydrochloric acid, to the sample under conditions effective for forming an aqueous solution of the sample; (b) introducing the aqueous solution of the sample into an inductively coupled mass spectrometer having a cell selected from the group of a reactive cell and a collision cell or both and producing an analyte ion comprising an interfering species; (c) contacting the analyte ion with a gas to produce a product which is substantially free from the interfering species; and (d) detecting and measuring at least one signal from the analyte in the solution. This disclosure further relates to a method for making an aqueous titanium, tin or silicon tetrachloride sample suitable for analysis in using inductively coupled plasma mass spectroscopy.

1 . A method for detecting at least one analyte in a sample comprising one or more of titanium tetrachloride, tin tetrachloride or silicon tetrachloride using an inductively coupled mass spectrometer; comprising,
 (a) contacting an aqueous stabilizing acid and the sample under conditions effective for forming an aqueous solution of the sample;   (b) introducing the aqueous solution of the sample into the inductively coupled mass spectrometer having a cell selected from the group of a reactive cell and a collision cell or both and producing an analyte ion comprising at least one interfering species;   (c) contacting the analyte ion with a gas to produce a product which is substantially free of the interfering species; and   (d) detecting and measuring at least one signal from the analyte in the aqueous solution of the sample.   
   
   
       2 . The process of  claim 1  wherein the stabilizing acid is hydrochloric acid. 
   
   
       3 . The process of  claim 1  wherein the sample is unpurified. 
   
   
       4 . The process of  claim 1  wherein the sample is purified. 
   
   
       5 . The process of  claim 1  wherein the temperature effective for forming an aqueous solution of the sample is below about 10° C. 
   
   
       6 . The process of  claim 1  wherein in which the sample comprises a major proportion of titanium tetrachloride the temperature effective for forming an aqueous solution of the sample is above the freezing point of the titanium tetrachloride sample but below about 10° C. 
   
   
       7 . The process of  claim 6  wherein the temperature effective for forming an aqueous solution of the sample is between about 0° C. and about 10° C. 
   
   
       8 . The process of  claim 1  wherein the conditions effective for stabilizing the sample prevent a loss of volatile elements during an exothermic reaction of the sample and the aqueous stabilizing acid. 
   
   
       9 . The process of  claim 1  wherein the gas is a reaction gas. 
   
   
       10 . The process of  claim 1  wherein the gas is hydrogen. 
   
   
       11 . The process of  claim 1  wherein the gas is a collision gas. 
   
   
       12 . The process of  claim 1  wherein the gas is helium. 
   
   
       13 . The process of  claim 1  wherein the sample comprises a major proportion of titanium tetrachloride and the stabilizing acid is hydrochloric acid. 
   
   
       14 . The process of  claim 13  wherein the aqueous solution of hydrochloric acid ranges from a concentration of about 3% to about 36% based on the weight of the aqueous hydrochloric acid solution. 
   
   
       15 . The process of  claim 1  wherein the sample comprises a major proportion of titanium tetrachloride and the solution of the sample has a titanium tetrachloride concentration ranging from about 5% to about 30% based on the total weight of the solution of the sample. 
   
   
       16 . The process of  claim 1  wherein the analyte is one or more of the following elements: arsenic, antimony, aluminum, silicon, calcium, vanadium, tin, iron, chromium, copper, cadmium, lead, magnesium, manganese, nickel, niobium, zirconium, zinc, barium, cobalt and mercury and an oxide, chloride, or hydride thereof. 
   
   
       17 . The method of  claim 1  wherein the stabilizing acid is added to the sample. 
   
   
       18 . A method for making an aqueous sample comprising titanium, tin or silicon tetrachloride suitable for analysis by inductively coupled plasma mass spectrometry, comprising:
 chilling the sample;   chilling an aqueous solution of a stabilizing acid;   forming a solution of the sample and the acid by contacting the chilled sample with the chilled aqueous solution of the stabilizing acid at a rate sufficient for maintaining the solution temperature below about 10° C. while agitating the sample.   
   
   
       19 . The method of  claim 18  wherein the stabilizing acid is added to the sample. 
   
   
       20 . The method of  claim 18  wherein the sample comprising a major proportion of titanium tetrachloride and the stabilizing acid comprises hydrochloric acid. 
   
   
       21 . The process of  claim 20  wherein the aqueous solution of hydrochloric acid ranges from a concentration of about 3% to about 36% based on the weight of the aqueous hydrochloric acid solution. 
   
   
       22 . The process of  claim 18  wherein the sample comprises a major proportion of titanium tetrachloride and the solution of the sample has a titanium tetrachloride concentration ranging from about 5% to about 30% based on the total weight of the solution of the sample.