應用實績>Biotector TOC分析儀於高TIC(總無機碳)之水質監測
Reliable Operation of BioTector in High TIC Applications
 
背景介紹
TIC is defined as the sum of carbon present in water, consisting of elemental carbon, total carbon dioxide, carbon monoxide, cyanide, cyanate, and thiocyanate (in water analysis guidelines and norms). TOC instruments mostly register TIC as the CO2 originating from carbonates and hydrogen carbonates. TIC is removed by the acidification of the sample to a pH of typically less than 2 and purging of the CO2 gas with a carrier gas such as oxygen (O2). TIC is regarded as a non contaminant in water treatment plants and in most applications.
TIC定義為水中存在的碳的總和,由元素碳,總二氧化碳,一氧化碳,氰化物,氰酸鹽和硫氰酸鹽組成(依水分析指南和規範)。 TOC儀器主要將TIC記錄為源自碳酸鹽和碳酸氫鹽的CO 2。 透過將樣品酸化至通常小於2的pH值,並用載氣如氧氣(O 2)清除CO 2氣體來消除TIC。 在水處理廠以及大多數應用中,TIC被視為非污染物。
 
In conventional TOC technologies (e.g. thermal combustion and UV persulfate) a small quantity of acid is mixed with the sample, and a fixed TIC removal time is applied. If the TIC concentrations are high or when the TIC levels increase unexpectedly in the water sample, the injection of the small quantity acid and the use of fixed time results in incomplete removal of the TIC from the sample. The consequence of inefficient TIC removal is critical because the TOC, which is a contaminant, will be measured inaccurately due to insufficient removal of TIC from the sample. 
傳統TOC技術(例如 : 熱燃燒和UV過硫酸鹽),將少量酸與水樣混合,並於固定的時間內去除TIC。 如果TIC濃度高或當水樣中TIC水平不預期地增加時,注入少量酸以及採用固定時間處理並不能完全去除水樣中的TIC。 低效率去除TIC具有關鍵影響,因為如果沒有完全去除水樣中的TIC,TOC這類污染物的測量即不會準確。
 
In Hach BioTector analyzers, surplus quantity of acid injection is applied, and the TIC removal is automatically extended by monitoring the CO2 levels continuously until all TIC is removed from the sample. This operation guarantees accurate and reliable TIC and TOC analysis.
Hach BioTector分析儀,注入大量的酸,並透過持續監測CO2水平以自動延長TIC去除程序,直到從樣品中完全去除TIC。 此操作設計確保準確可靠的TIC和TOC分析。
 
Problem 面對的問題
Depending on pH and composition of the water sample, the total inorganic carbon (TIC) concentration levels could be relatively high compared to the total organic carbon (TOC) concentrations.  Conventional TOC technologies apply a fixed-time TIC removal process. If TIC is not removed efficiently from the sample before the TOC analysis, this could have adverse effects such as carryover of TIC into the TOC measurement—thus higher and inaccurate TOC analysis.
取決於水樣的pH和組成成分,與總有機碳(TOC)濃度相比,總無機碳(TIC)濃度水平可能相對較高。 傳統的TOC技術採用固定時間的TIC消除程序。 惟如果在進行TOC分析之前未有效消除樣品中的TIC,則可能產生負面影響,例如TIC殘留到TOC測量中 - 因而產生更高且不準確的TOC分析數值。
 
Solution
The Hach® BioTector Online TOC Analyzer, which utilizes an advanced TIC removal and operation sequence, was developed to handle high TIC concentration samples efficiently. The system monitors the TIC levels continuously using its nondispersive infrared (NDIR) CO2 analyzer, and does not start TOC analysis until all TIC is guaranteed to be removed from the sample.
Hach® BioTector線上TOC分析儀採用先進的TIC消除技術和操作順序,有效處理高TIC濃度水樣。 BioTector線上TOC分析系統使用非分散紅外線(NDIR)CO2分析儀連續監測TIC水平,並確保將所有TIC自水樣中移除之後才會啟動TOC分析。
 
Benefits
BioTector’s advanced TIC monitoring mechanism leads to an efficient TIC removal from the water sample, and provides accurate, reliable TIC and TOC results in many applications. BioTector’s efficient TIC removal process results in reliable analysis, and prevents overestimation of the TOC results and generation of unnecessary alarm signals. 
BioTector線上TOC分析儀先進的TIC監測機制可有效去除水樣中之TIC,並針對許多應用提供準確可靠的TIC和TOC結果。 BioTector的高效率TIC去除過程完成可靠分析,並防止TOC結果被高估而產生不必要的警告訊號。
 
How Does BioTector’s TIC Removal Work?
BioTector has an “automatic extension” mechanism, which is activated during the TIC analysis if the CO2 level does not drop below a certain checkpoint at the end of the TIC removal phase. When necessary, BioTector automatically extends the TIC sparge time, until all the CO2 coming from TIC is removed from the sample. This mechanism is a “dynamic endpoint detection, which guarantees the complete removal of the TIC from the sample before the TOC measurement is initiated.
BioTector具有“自動延長”機制,如果在TIC清除階段結束時CO2水平沒有降至某個檢查點以下,則在TIC分析期間啟動該機制。 必要時,BioTector會自動延長TIC吹掃時間,直到從樣品中去除所有來自TIC的CO2。 此機制為“動態終點檢測"以確保在TOC測量開始之前完全去除水樣中之TIC。
 
During the TIC sparging phase, BioTector monitors the CO2 levels in the sample with its NDIR CO2 analyzer. If the CO2 level is not reduced to the pre-programmed “TIC Check” CO2 concentration level, BioTector automatically extends the TIC phase until all CO2 is removed from the sample.
在TIC吹掃階段,BioTector使用NDIR CO2分析儀監測樣品中的CO2濃度。 如果CO2水平未降低到預先編寫的“TIC Check”CO2濃度水平,BioTector會自動延長TIC階段,直到從樣品中除去所有CO2。
 
The “TIC Check” CO2 concentration level is programmed based on system specification, such as the analyzer’s detection limit, where the “TIC Check” CO2 gas concentration corresponds to a negligible quantity of TIC. This standard BioTector software feature guarantees that all TIC is completely removed from the sample. Therefore, the possibility of any TIC carryover to the TOC analysis is removed with this mechanism. This feature has been proven to be critical for the analysis of samples containing high or significantly fluctuating concentrations of TIC.
 “TIC檢查”CO2濃度水平是根據系統規格來編寫程式,例如分析儀的檢測限,其中“TIC檢查”CO2氣體濃度對應於可忽略不計的TIC數量。 這個BioTector標準軟體功能可確保完全去除水樣中所有TIC。 因此,利用此機制消除任何TIC殘留到TOC分析階段的可能性。 此特徵對於分析含有高或顯著波動的TIC濃度的水樣是極為關鍵的。
 
Figure 1 illustrates the “automatic extension” with an example TIC CO2 peak endpoint detection.  圖1 : 顯示具有TIC CO2峰值終點偵測範例之“自動延長”。
 
在常規TOC技術中使用固定時間TIC去除時TIC殘留至TOC
TIC Check
TIC CHECK表示TIC階段的CO2檢查點。 如果在TIC階段結束時,CO2水平高於設定的檢查點,則分析儀會自動將TIC SPARGE TIME延長1秒並再次檢查CO2水平。
  • 如果TIC級別在最長300秒的延長時間結束時仍未降至檢查點以下,系統將產生“TIC OVERFLOW”警告。
 
TIC Sparge Time
BioTector在TIC SPARGE TIME期間吹掃並測量水樣之TIC含量。
  • 如果在TIC SPARGE TIME結束時TIC級別沒有降至TIC CHECK水平以下,BioTector會自動延長此時間,直到TIC級別降至TIC CHECK級別以下。
  • 當TIC級別在最大延長時間(即300秒)結束時未降至TIC CHECK級別以下時,將產生“TIC OVERFLOW”警示。
 
在固定時間內消除TIC時,CO2氣體(如圖2中的陰影區域所示)繼續測量TOC。
 
Figure 2: TIC carryover to TOC in conventional TOC technologies  圖2:傳統TOC技術中TIC殘留至TOC
 
Conclusions  
The Hach BioTector online TOC analyzer applies an advanced TIC removal process where the system monitors the TIC levels continuously and guarantees the complete removal of TIC from the sample. This operation mechanism provides accurate and reliable measurement of TIC and TOC in the industry, and prevents overestimation of the TOC results and generation of unnecessary alarm signals
Hach BioTector線上TOC分析儀採用先進的TIC消除程序設計,系統連續監測TIC水平,並確保完全消除水樣中的TIC。 此操作機制準確和可靠測量TIC和TOC,並防止高估TOC結果和產生不必要的警告訊號。
 
Application Notes (點進下方標題以詳閱原文) Type Language Size Date Edition
Reliable Operation of BioTector in High TIC Applications 
DOC043.53.30364
  English US 469 KB 2016-08 Aug16