Reporting the sensitivity of Laser Induced Fluorescence instruments used for HO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; detection to an interference from RO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; radicals and introducing a novel approach that enables HO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; and certain RO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; types to be selectively measured