Xi'An, China
CIPAC Meeting 2027
CIPAC Meeting 2027

MT 162 - Determination of ethylenethiourea (ETU) (Imidazoldine-2-thione)


Content Handbook F

 

Outline of method

162.1 HPLC method (Referee method)

The ETU is extracted from the sample with methanol. An aliquot of the methanolic solution is evaporated to dryness and the residue is dissolved in water. The solution is filtered and diluted, if necessary, and injected on to a column of Nucleosil C18 or Spherisorb ODS. The ETU is eluted with water containing tetrahydrofuran and detected at 233 nm.

162.2 Paper chromatographic method

The ETU is extracted from the sample with methanol. Portions of the sample and standard solutions are spotted on to filter paper and developed with butan-1-ol + ethanol + water. The chromatogram is sprayed with pentacyanoaminoferroate [PCAF] reagent which produces a blue spot with ETU. The ETU content of the sample is determined by comparing the spot with those from the standards.
  

Scope

The methods are suitable for determining ETU in technical and formulated products containing ethylene-bis-(dithiocarbamate) (mancozeb, maneb, zineb and metiram).
 


Failed to start the session because headers have already been sent by "D:\www\www83\plugins\system\debug\src\Extension\Debug.php" at line 377. (500 Whoops, looks like something went wrong.)

RuntimeException RuntimeException

HTTP 500 Whoops, looks like something went wrong.

Failed to start the session because headers have already been sent by "D:\www\www83\plugins\system\debug\src\Extension\Debug.php" at line 377.

Exceptions 2

RuntimeException

in D:\www\www83\libraries\vendor\joomla\session\src\Storage\NativeStorage.php (line 454)
  1. if ($this->isActive()) {
  2. throw new \RuntimeException('Failed to start the session: already started by PHP.');
  3. }
  5. if (ini_get('session.use_cookies') && headers_sent($file, $line)) {
  6. throw new \RuntimeException(
  7. sprintf('Failed to start the session because headers have already been sent by "%s" at line %d.', $file, $line)
  8. );
  9. }
  11. if (!session_start()) {
NativeStorage->start() in D:\www\www83\libraries\src\Session\Storage\JoomlaStorage.php (line 313)
  1. $this->setId($session_clean);
  2. $cookie->set($session_name, '', ['expires' => time() - 3600 ]);
  3. }
  4. }
  6. parent::start();
  8. // Try loading data from the session
  9. if (!empty($_SESSION['joomla'])) {
  10. $this->data = unserialize(base64_decode($_SESSION['joomla']));
  11. }
JoomlaStorage->start() in D:\www\www83\libraries\vendor\joomla\session\src\Session.php (line 396)
  1. {
  2. if ($this->isStarted()) {
  3. return;
  4. }
  6. $this->store->start();
  8. $this->setState(SessionState::ACTIVE);
  10. // Initialise the session
  11. $this->setCounter();
Session->start() in D:\www\www83\libraries\vendor\joomla\session\src\Session.php (line 327)
  1. * @since 1.0
  2. */
  3. public function has($name)
  4. {
  5. if (!$this->isActive()) {
  6. $this->start();
  7. }
  9. return $this->store->has($name);
  10. }
Session->has() in D:\www\www83\libraries\src\Session\Session.php (line 194)
  2. $name = $args[2] . '.' . $name;
  3. }
  4. }
  6. if (parent::has($name)) {
  7. // Parent is used because of b/c, can be changed in Joomla 6
  8. return parent::get($name, $default);
  9. }
  11. /*
Session->get() in D:\www\www83\libraries\src\Factory.php (line 372)
  1. __CLASS__
  2. ),
  3. E_USER_DEPRECATED
  4. );
  6. $instance = self::getApplication()->getSession()->get('user');
  8. if (\is_null($id)) {
  9. if (!($instance instanceof User)) {
  10. $instance = User::getInstance();
  11. }
Factory::getUser() in D:\www\www83\libraries\src\Document\Renderer\Html\ModulesRenderer.php (line 46)
  1. {
  2. $renderer = $this->_doc->loadRenderer('module');
  3. $buffer = '';
  5. $app = Factory::getApplication();
  6. $user = Factory::getUser();
  7. $frontediting = ($app->isClient('site') && $app->get('frontediting', 1) && !$user->guest);
  8. $menusEditing = ($app->get('frontediting', 1) == 2) && $user->authorise('core.edit', 'com_menus');
  10. foreach (ModuleHelper::getModules($position) as $mod) {
  11. $moduleHtml = $renderer->render($mod, $params, $content);
ModulesRenderer->render() in D:\www\www83\libraries\src\Document\HtmlDocument.php (line 578)
  2. $cbuffer[$hash] = $tmpdata;
  4. $cache->store($cbuffer, 'cbuffer_' . $type);
  5. } else {
  6. $this->setBuffer($renderer->render($name, $attribs, null), $type, $name, $title);
  7. }
  9. return parent::$_buffer[$type][$name][$title];
  10. }
HtmlDocument->getBuffer() in D:\www\www83\libraries\src\Document\HtmlDocument.php (line 897)
  1. $replace = [];
  2. $with = [];
  4. foreach ($this->_template_tags as $jdoc => $args) {
  5. $replace[] = $jdoc;
  6. $with[] = $this->getBuffer($args['type'], $args['name'], $args['attribs']);
  7. }
  9. return str_replace($replace, $with, $this->_template);
  10. }
  11. }
HtmlDocument->_renderTemplate() in D:\www\www83\libraries\src\Document\HtmlDocument.php (line 650)
  2. if (\array_key_exists('csp_nonce', $params) && $params['csp_nonce'] !== null) {
  3. $this->cspNonce = $params['csp_nonce'];
  4. }
  6. $data = $this->_renderTemplate();
  7. parent::render($caching, $params);
  9. return $data;
  10. }
HtmlDocument->render() in D:\www\www83\libraries\src\Document\ErrorDocument.php (line 139)
  1. $this->debug = $params['debug'] ?? false;
  2. $this->error = $this->_error;
  4. $params['file'] = 'error.php';
  6. return parent::render($cache, $params);
  7. }
  9. /**
  10. * Render the backtrace
  11. *
ErrorDocument->render() in D:\www\www83\libraries\src\Error\Renderer\HtmlRenderer.php (line 70)
  1. ob_end_clean();
  2. }
  4. $this->getDocument()->setTitle(Text::_('Error') . ': ' . $error->getCode());
  6. return $this->getDocument()->render(
  7. false,
  8. [
  9. 'template' => $template->template,
  10. 'directory' => JPATH_THEMES,
  11. 'debug' => JDEBUG,
HtmlRenderer->render() in D:\www\www83\libraries\src\Exception\ExceptionHandler.php (line 142)
  1. 'subject' => $app,
  2. 'document' => $renderer->getDocument(),
  3. ])
  4. );
  6. $data = $renderer->render($error);
  8. // If nothing was rendered, just use the message from the Exception
  9. if (empty($data)) {
  10. $data = $error->getMessage();
  11. }
ExceptionHandler::render() in D:\www\www83\libraries\src\Exception\ExceptionHandler.php (line 76)
  1. * @since 3.10.0
  2. */
  3. public static function handleException(\Throwable $error)
  4. {
  5. static::logException($error);
  6. static::render($error);
  7. }
  9. /**
  10. * Render the error page based on an exception.
  11. *
ExceptionHandler::handleException() in D:\www\www83\libraries\src\Application\CMSApplication.php (line 334)
  1. );
  3. // Trigger the onError event.
  4. $this->dispatchEvent('onError', $event);
  6. ExceptionHandler::handleException($event->getError());
  7. }
  9. // Trigger the onBeforeRespond event.
  10. $this->dispatchEvent(
  11. 'onBeforeRespond',
CMSApplication->execute() in D:\www\www83\index.php (line 35)
  2. // Run the application - All executable code should be triggered through this file
  3. require_once dirname(__FILE__) . '/includes/app.php';
  5. $app = JFactory::getApplication('site');
  6. $app->execute();

RuntimeException

Failed to start the session because headers have already been sent by "D:\www\www83\plugins\system\debug\src\Extension\Debug.php" at line 377.

in D:\www\www83\libraries\vendor\joomla\session\src\Storage\NativeStorage.php (line 454)
  1. if ($this->isActive()) {
  2. throw new \RuntimeException('Failed to start the session: already started by PHP.');
  3. }
  5. if (ini_get('session.use_cookies') && headers_sent($file, $line)) {
  6. throw new \RuntimeException(
  7. sprintf('Failed to start the session because headers have already been sent by "%s" at line %d.', $file, $line)
  8. );
  9. }
  11. if (!session_start()) {
NativeStorage->start() in D:\www\www83\libraries\src\Session\Storage\JoomlaStorage.php (line 313)
  1. $this->setId($session_clean);
  2. $cookie->set($session_name, '', ['expires' => time() - 3600 ]);
  3. }
  4. }
  6. parent::start();
  8. // Try loading data from the session
  9. if (!empty($_SESSION['joomla'])) {
  10. $this->data = unserialize(base64_decode($_SESSION['joomla']));
  11. }
JoomlaStorage->start() in D:\www\www83\libraries\vendor\joomla\session\src\Session.php (line 396)
  1. {
  2. if ($this->isStarted()) {
  3. return;
  4. }
  6. $this->store->start();
  8. $this->setState(SessionState::ACTIVE);
  10. // Initialise the session
  11. $this->setCounter();
Session->start() in D:\www\www83\libraries\vendor\joomla\session\src\Session.php (line 327)
  1. * @since 1.0
  2. */
  3. public function has($name)
  4. {
  5. if (!$this->isActive()) {
  6. $this->start();
  7. }
  9. return $this->store->has($name);
  10. }
Session->has() in D:\www\www83\libraries\src\Session\Session.php (line 194)
  2. $name = $args[2] . '.' . $name;
  3. }
  4. }
  6. if (parent::has($name)) {
  7. // Parent is used because of b/c, can be changed in Joomla 6
  8. return parent::get($name, $default);
  9. }
  11. /*
Session->get() in D:\www\www83\libraries\src\Factory.php (line 372)
  1. __CLASS__
  2. ),
  3. E_USER_DEPRECATED
  4. );
  6. $instance = self::getApplication()->getSession()->get('user');
  8. if (\is_null($id)) {
  9. if (!($instance instanceof User)) {
  10. $instance = User::getInstance();
  11. }
Factory::getUser() in D:\www\www83\libraries\src\Application\SiteApplication.php (line 565)
  1. *
  2. * @since 3.2
  3. */
  4. protected function initialiseApp($options = [])
  5. {
  6. $user = Factory::getUser();
  8. // If the user is a guest we populate it with the guest user group.
  9. if ($user->guest) {
  10. $guestUsergroup = ComponentHelper::getParams('com_users')->get('guest_usergroup', 1);
  11. $user->groups = [$guestUsergroup];
SiteApplication->initialiseApp() in D:\www\www83\libraries\src\Application\SiteApplication.php (line 237)
  1. * @since 3.2
  2. */
  3. protected function doExecute()
  4. {
  5. // Initialise the application
  6. $this->initialiseApp();
  8. // Mark afterInitialise in the profiler.
  9. JDEBUG ? $this->profiler->mark('afterInitialise') : null;
  11. // Route the application
SiteApplication->doExecute() in D:\www\www83\libraries\src\Application\CMSApplication.php (line 304)
  1. $this->sanityCheckSystemVariables();
  2. $this->setupLogging();
  3. $this->createExtensionNamespaceMap();
  5. // Perform application routines.
  6. $this->doExecute();
  8. // If we have an application document object, render it.
  9. if ($this->document instanceof \Joomla\CMS\Document\Document) {
  10. // Render the application output.
  11. $this->render();
CMSApplication->execute() in D:\www\www83\index.php (line 35)
  2. // Run the application - All executable code should be triggered through this file
  3. require_once dirname(__FILE__) . '/includes/app.php';
  5. $app = JFactory::getApplication('site');
  6. $app->execute();

Stack Traces 2

[2/2] RuntimeException 
RuntimeException:
Failed to start the session because headers have already been sent by "D:\www\www83\plugins\system\debug\src\Extension\Debug.php" at line 377.

  at D:\www\www83\libraries\vendor\joomla\session\src\Storage\NativeStorage.php:454
  at Joomla\Session\Storage\NativeStorage->start()
     (D:\www\www83\libraries\src\Session\Storage\JoomlaStorage.php:313)
  at Joomla\CMS\Session\Storage\JoomlaStorage->start()
     (D:\www\www83\libraries\vendor\joomla\session\src\Session.php:396)
  at Joomla\Session\Session->start()
     (D:\www\www83\libraries\vendor\joomla\session\src\Session.php:327)
  at Joomla\Session\Session->has()
     (D:\www\www83\libraries\src\Session\Session.php:194)
  at Joomla\CMS\Session\Session->get()
     (D:\www\www83\libraries\src\Factory.php:372)
  at Joomla\CMS\Factory::getUser()
     (D:\www\www83\libraries\src\Document\Renderer\Html\ModulesRenderer.php:46)
  at Joomla\CMS\Document\Renderer\Html\ModulesRenderer->render()
     (D:\www\www83\libraries\src\Document\HtmlDocument.php:578)
  at Joomla\CMS\Document\HtmlDocument->getBuffer()
     (D:\www\www83\libraries\src\Document\HtmlDocument.php:897)
  at Joomla\CMS\Document\HtmlDocument->_renderTemplate()
     (D:\www\www83\libraries\src\Document\HtmlDocument.php:650)
  at Joomla\CMS\Document\HtmlDocument->render()
     (D:\www\www83\libraries\src\Document\ErrorDocument.php:139)
  at Joomla\CMS\Document\ErrorDocument->render()
     (D:\www\www83\libraries\src\Error\Renderer\HtmlRenderer.php:70)
  at Joomla\CMS\Error\Renderer\HtmlRenderer->render()
     (D:\www\www83\libraries\src\Exception\ExceptionHandler.php:142)
  at Joomla\CMS\Exception\ExceptionHandler::render()
     (D:\www\www83\libraries\src\Exception\ExceptionHandler.php:76)
  at Joomla\CMS\Exception\ExceptionHandler::handleException()
     (D:\www\www83\libraries\src\Application\CMSApplication.php:334)
  at Joomla\CMS\Application\CMSApplication->execute()
     (D:\www\www83\index.php:35)
[1/2] RuntimeException 
RuntimeException:
Failed to start the session because headers have already been sent by "D:\www\www83\plugins\system\debug\src\Extension\Debug.php" at line 377.

  at D:\www\www83\libraries\vendor\joomla\session\src\Storage\NativeStorage.php:454
  at Joomla\Session\Storage\NativeStorage->start()
     (D:\www\www83\libraries\src\Session\Storage\JoomlaStorage.php:313)
  at Joomla\CMS\Session\Storage\JoomlaStorage->start()
     (D:\www\www83\libraries\vendor\joomla\session\src\Session.php:396)
  at Joomla\Session\Session->start()
     (D:\www\www83\libraries\vendor\joomla\session\src\Session.php:327)
  at Joomla\Session\Session->has()
     (D:\www\www83\libraries\src\Session\Session.php:194)
  at Joomla\CMS\Session\Session->get()
     (D:\www\www83\libraries\src\Factory.php:372)
  at Joomla\CMS\Factory::getUser()
     (D:\www\www83\libraries\src\Application\SiteApplication.php:565)
  at Joomla\CMS\Application\SiteApplication->initialiseApp()
     (D:\www\www83\libraries\src\Application\SiteApplication.php:237)
  at Joomla\CMS\Application\SiteApplication->doExecute()
     (D:\www\www83\libraries\src\Application\CMSApplication.php:304)
  at Joomla\CMS\Application\CMSApplication->execute()
     (D:\www\www83\index.php:35)