有機(jī)肥料 有機(jī)質(zhì)含量的測定 電位滴定法編制說明

團(tuán)體標(biāo)準(zhǔn)有機(jī)肥料有機(jī)質(zhì)含量的測定電位滴定法編制說明（征求意見稿）團(tuán)體標(biāo)準(zhǔn)《有機(jī)肥料中有機(jī)質(zhì)含量的測定電位滴定法》編制說明（送審稿）一、項目來源、起草單位根據(jù)《廣西肥料協(xié)會關(guān)于下達(dá)2024年第四批團(tuán)體標(biāo)準(zhǔn)項目計劃的通知》（廣肥協(xié)[2024]18號）的要求，團(tuán)體標(biāo)準(zhǔn)《有機(jī)肥料有機(jī)質(zhì)含量的測定電位滴定法》制定項目由廣西肥料協(xié)會歸口，項目周期為6個月，完成年限為2025年1月，標(biāo)準(zhǔn)起草單位為：廣西壯族自治區(qū)分析測試研究中心、廣西壯族自治區(qū)分析測試研究中心、廣西壯族自治區(qū)南寧生態(tài)環(huán)境監(jiān)測中心、廣西西大檢測有限公司、廣西壯族自治區(qū)新材料技術(shù)工程院等。二、項目背景、必要性和意義 目前國家標(biāo)準(zhǔn)GB/T18877-2020《有機(jī)無機(jī)復(fù)混肥料》及農(nóng)業(yè)行業(yè)標(biāo)準(zhǔn)NY/T525-2021《有機(jī)肥料》中有機(jī)質(zhì)的測定采用的是手工滴定法，通過指示劑來判斷滴定終點。然而，滴定分析法中有時溶液太渾濁、顏色較深，如使用指示劑指示終點不利觀察終點，造成終點誤差較大，使結(jié)果的準(zhǔn)確度受到極大的影響。電位滴定法使儀器分析法與化學(xué)分析法有效結(jié)合起來，利用溶液的電極電位的變化來指示終點，避免了溶液狀態(tài)的影響以及人為判斷終點的誤差，靈敏度和準(zhǔn)確度都得到了很大的提高。當(dāng)樣品量大時，自動電位滴定法具有明顯的優(yōu)勢，不僅測定結(jié)果不受主觀意識影響，而且可以解放檢測人員的雙手，大大提高了勞動效率。另外，隨著時代的發(fā)展，科技的進(jìn)步，自動電位滴定儀普及率越來越高，儀器價格越來越實惠，自動化和智能化也不斷提升，可借助計算機(jī)軟件進(jìn)行在線控制進(jìn)而實現(xiàn)自動化和連續(xù)測定，是應(yīng)用前景廣闊的電化學(xué)分析方法。然而，目前的情況是許多檢測機(jī)構(gòu)擁有這樣的儀器而沒有配套的方法可用。因此，有機(jī)肥料中有機(jī)質(zhì)含量的測定—自動電位滴定法的立項是非常有必要的，它可以豐富了有機(jī)質(zhì)的檢測方法，滿足不同機(jī)構(gòu)不同人員不同機(jī)構(gòu)的檢測需求。通過查詢工標(biāo)網(wǎng)、標(biāo)準(zhǔn)云、萬方數(shù)據(jù)庫、知網(wǎng)數(shù)據(jù)庫等平臺，未發(fā)現(xiàn)有涉及標(biāo)準(zhǔn)、專利等文獻(xiàn)。三、承擔(dān)單位情況廣西壯族自治區(qū)分析測試研究中心（以下簡稱“中心）為公益二類事業(yè)單位，成立于1978年，是廣西科技廳直屬的以分析測試技術(shù)研究、理化分析為主的省級綜合分析測試研究機(jī)構(gòu)，是廣西質(zhì)量技術(shù)監(jiān)督局授權(quán)建立的“廣西壯族自治區(qū)保健食品及生物產(chǎn)品質(zhì)量監(jiān)督檢驗站”，屬于為社會公眾服務(wù)、對外獨立開展檢驗/檢測業(yè)務(wù)的第三方檢測研究機(jī)構(gòu)。中心現(xiàn)有職工82人，其中高級職稱18人，中級職稱29人，碩士研究生17人，從事質(zhì)檢工作76人。中心擁有固定資產(chǎn)7809萬元，儀器設(shè)備1402臺套，其中50萬元以上的大型儀器37臺套，20萬以上儀器92臺套，如氣相色譜/質(zhì)譜聯(lián)用儀（GC/MS）、液相色譜/質(zhì)譜聯(lián)用儀（LC/MS）、氣相色譜/紅外光譜聯(lián)用儀（GC/RFX）、氨基酸分析儀、全自動遺傳分析儀、高效液相色譜儀、全自動超高壓液相色譜儀、等離子發(fā)射光譜儀（ICP）、等離子體質(zhì)譜儀(ICP/MS)、離子色譜儀（IC）、X射線熒光光譜儀、原子熒光分光光度計、原子吸收分光光度計等。歷年來中心承擔(dān)多項省部級重要課題，獲得科技成果27項，其中廣西科技進(jìn)步獎8項。中心承擔(dān)各類產(chǎn)品質(zhì)量技術(shù)標(biāo)準(zhǔn)的撰寫起草工作，其中3項國家行業(yè)標(biāo)準(zhǔn)、22項廣西地方標(biāo)準(zhǔn)和50項企業(yè)標(biāo)準(zhǔn)已通過有關(guān)主管部門認(rèn)可發(fā)布實施。中心在生物樣品有效成分分析、有益活性菌分析、保健食品功效成份分析、農(nóng)藥殘留、獸藥殘留檢測等領(lǐng)域處于廣西領(lǐng)先水平。四、參編單位工作情況廣西壯族自治區(qū)分析測試研究中心負(fù)責(zé)統(tǒng)一樣品的收集和分發(fā)，分析方法的實驗研究，樣品測試結(jié)果的收集和處理，標(biāo)準(zhǔn)文本、試驗報告和編制說明的撰寫。廣西壯族自治區(qū)南寧生態(tài)環(huán)境監(jiān)測中心、廣西西大檢測有限公司、廣西壯族自治區(qū)新材料技術(shù)工程院方法驗證單位，負(fù)責(zé)對試驗報告中的條件試驗進(jìn)行驗證，并對標(biāo)準(zhǔn)文本提出修改意見。五、標(biāo)準(zhǔn)起草過程廣西壯族自治區(qū)分析測試研究中心接到《有機(jī)肥料有機(jī)質(zhì)含量的測定電位滴定法》的制定任務(wù)后，立即組織相關(guān)工程技術(shù)人員成立了標(biāo)準(zhǔn)編制組，進(jìn)行相關(guān)資料的查詢與收集工作，制訂工作計劃和進(jìn)度安排。編制組首先查閱大量材料，并根據(jù)NY/T525-2021《有機(jī)肥料》中有機(jī)質(zhì)含量測定的原理，設(shè)計出一個初步的檢測方案，然后再制定出實驗的每一個具體操作步驟。通過大量的實驗，不斷完善實驗步驟，優(yōu)化檢測方案，然后確定出一個檢測結(jié)果穩(wěn)定、操作簡單的實驗方法。在此基礎(chǔ)上，于2024年11月形成了標(biāo)準(zhǔn)的討論稿和編制說明。本標(biāo)準(zhǔn)討論稿完成后，在編制組及單位內(nèi)部進(jìn)行了多次交流，廣泛征求意見，對本標(biāo)準(zhǔn)討論稿進(jìn)行了認(rèn)真的修改和完善，最后形成了該標(biāo)準(zhǔn)的征求意見稿。六、標(biāo)準(zhǔn)的制訂原則、主要內(nèi)容與論據(jù)（一）標(biāo)準(zhǔn)編制的原則該標(biāo)準(zhǔn)按照GB/T1.1—2020《標(biāo)準(zhǔn)化工作導(dǎo)則第1部分：標(biāo)準(zhǔn)化文件的結(jié)構(gòu)和起草規(guī)則》的規(guī)定和要求編寫。本文件堅持以實際的可操作性為前提，以滿足其準(zhǔn)確性、實踐性、適應(yīng)性、便捷性等需要為原則。（二）確定標(biāo)準(zhǔn)的主要內(nèi)容1、標(biāo)準(zhǔn)題目與用途本文件的立項名稱為：“有機(jī)肥料有機(jī)質(zhì)含量的測定——電位滴定法”，在標(biāo)準(zhǔn)征求意見的過程中未提出其他建議，確定為此項標(biāo)準(zhǔn)的名稱。本標(biāo)準(zhǔn)規(guī)定了有機(jī)肥料有機(jī)質(zhì)含量的測定電位滴定法的試驗方法。本標(biāo)準(zhǔn)適用于有機(jī)肥有機(jī)質(zhì)的測定。2、試劑和材料表1所需試劑和材料名稱規(guī)格所需濃度重鉻酸鉀基準(zhǔn)物質(zhì)0.2mol/L重鉻酸鉀分析純0.8mol/L濃硫酸分析純98%濃硝酸分析純98%硫酸亞鐵銨分析純0.2mol/L二氧化硅分析純固體3、設(shè)備0.01mg感量分析天平、石墨消解爐、電位滴定儀以及常用的儀器設(shè)備。4、試驗步驟（1）試樣的制備樣品（鮮樣）經(jīng)過多次縮分后，分取約600g，風(fēng)干后繼續(xù)進(jìn)行多次縮分，分取約100g，迅速研磨至全部通過1.00mm孔徑尼龍篩，混勻，置于潔凈、干燥的容器中。（2）氧化稱取制備好的風(fēng)干樣品0.04～0.1g（精確到0.00001g），置于50mL硬質(zhì)玻璃試管中，用移液管準(zhǔn)確加入0.8mol/L重鉻酸鉀溶液10.00mL，再加入10.0mL濃硫酸，瓶口放置一個小漏斗，置于已升溫至190℃的石墨消解爐中加熱10分鐘。取出冷卻至室溫，用少量純水沖洗小漏斗至試管中，備用。（3）滴定將處理好的試樣（6.2）全部轉(zhuǎn)移至400mL的高型燒杯中，用少量純水沖洗試管數(shù)遍，合并于高型燒杯中，并加水至200mL左右，置于滴定儀的磁力攪拌器上，插入滴定劑出液管和指示電極，啟動滴定設(shè)備以及攪拌器，設(shè)置好加液步長、等當(dāng)點識別標(biāo)準(zhǔn)等滴定參數(shù)，用硫酸亞鐵銨標(biāo)準(zhǔn)溶液進(jìn)行滴定。如已知樣品大致濃度，可快速加入滴定劑，直到距離終點5mL左右再繼續(xù)以一定的速度（如0.05mL或逐滴)加入滴定劑，每滴一次達(dá)到電位平衡后，記錄滴定管讀數(shù)和電位值，繼續(xù)滴定通過終點，通過插值或滴定曲線確定終點，或由儀器自帶軟件確定終點。（4）空白試驗用二氧化硅代替試樣進(jìn)行空白試驗，其他步驟同試樣溶液的測定，空白試驗需做雙平行，滴定劑消耗體積取平均值。2次空白試驗的滴定結(jié)果應(yīng)滿足相對偏差小于0.2%，否則，需查找原因并重新進(jìn)行空白試驗及樣品分析。（5）計算有機(jī)質(zhì)含量以質(zhì)量分?jǐn)?shù)ω（%）表示，按以下公式計算。式中：c—硫酸亞鐵銨標(biāo)準(zhǔn)溶液的摩爾濃度，單位為摩爾每升（mol/L）；V0—空白試驗消耗硫酸亞鐵銨標(biāo)準(zhǔn)溶液的體積，單位為毫升（mL）；V—樣品測定消耗硫酸亞鐵銨標(biāo)準(zhǔn)溶液的體積，單位為毫升（mL）；m—風(fēng)干試樣質(zhì)量，單位為克（g）；X0—風(fēng)干試樣的水分含量，以小數(shù)點表示；3—四分之一碳原子的摩爾質(zhì)量數(shù)值，單位為克每摩爾（g/mol）；1.724—換算系數(shù)，即將有機(jī)碳換算為有機(jī)質(zhì)的系數(shù)。（三）主要技術(shù)指標(biāo)、參數(shù)、試驗驗證的論述稱樣量的改進(jìn)本方法前處理方法主要參考NY/T525-2021中有機(jī)質(zhì)的測定，但是對稱樣量做了調(diào)整，即減少稱樣量至原來的五分之一，而氧化之后的定容分取步驟就可以省去了。這樣一來，大大簡化了操作步驟，而且，更重要的一點是，節(jié)省了重鉻酸鉀及濃硫酸的用量，特別是重鉻酸鉀的用量，對節(jié)約成本及環(huán)保方面都起到很大的作用。因為重鉻酸鉀中的六價鉻有劇毒，定容分取后剩余的溶液中含有大量的六價鉻，屬于危廢，必須交由有資質(zhì)的單位進(jìn)行處置，這就增加了實驗室的成本。而減少稱樣量會增大稱量誤差，這可以使用感量為0.01mg的分析天平來稱量進(jìn)行彌補(bǔ)。氧化條件的優(yōu)化本法使用石墨消解爐來對試樣進(jìn)行氧化消解。石墨消解爐因其受熱均勻，升溫速度快，溫度穩(wěn)定，可以大批量消解樣品等優(yōu)點，已被大量實驗室引進(jìn)使用。然而想獲得滿意的分析結(jié)果，必須對氧化溫度及氧化時間這兩個重要的參數(shù)進(jìn)行優(yōu)化。因此，本項目選取一個有機(jī)質(zhì)含量為38.9%±2.1%標(biāo)準(zhǔn)樣品，以不同氧化溫度，不同氧化時間，對分析結(jié)果進(jìn)行了考察。氧化溫度的選擇保持氧化時間不變，考察不同溫度對結(jié)果的影響，并繪制溫度影響曲線，如圖1所示。由圖可知，分析結(jié)果隨著溫度升高開始緩慢增大，當(dāng)溫度到160℃后快速增大，190℃后又趨于平穩(wěn)。從分析結(jié)果的準(zhǔn)確性來看，氧化溫度180~200℃獲得的結(jié)果都是比較滿意的，因此將氧化溫度定為190℃±10℃。圖1氧化溫度對分析結(jié)果的影響曲線圖氧化時間的選擇保持氧化溫度190℃不變，考察不同溫度對結(jié)果的影響，并繪制時間影響曲線，如圖2所示。由圖可知，分析結(jié)果隨著氧化時間的延長開始緩慢增大，當(dāng)氧化時間延長到8min后分析結(jié)果提高較快，10min之后變化不大。從分析結(jié)果的準(zhǔn)確性來看，氧化時間9.5min至10.5min之間獲得的結(jié)果都是比較滿意的，因此將氧化時間定為10±0.5min。圖2氧化時間對分析結(jié)果的影響曲線圖標(biāo)準(zhǔn)樣品準(zhǔn)確度及精密度試驗為驗證本文件測試方法的適用性，由廣西壯族自治區(qū)分析測試研究中心提供代表性的有機(jī)肥料樣品，統(tǒng)一分配樣品并安排驗證試驗，包括標(biāo)準(zhǔn)樣品準(zhǔn)確度及精密度試驗、實際樣品測定結(jié)果重現(xiàn)性試驗。四家實驗室使用本文件測試方法對3個不同含量的標(biāo)準(zhǔn)樣品進(jìn)行了檢測分析，結(jié)果統(tǒng)計于表2。表2標(biāo)準(zhǔn)樣品試驗數(shù)據(jù)驗證單位樣品編號有機(jī)質(zhì)含量（%)平均值（%)標(biāo)準(zhǔn)值（%）相對標(biāo)準(zhǔn)偏差(%)極差(%)相對誤差（%）實驗室一RMK011a21.61,21.87,21.63,21.97,22.02,21.9421.521.1±1.30.810.471.90RMK02133.41,33.43,33.25,33.56,33.12,33.2333.333.2±1.80.480.440.30RMH-F11138.28,38.60,38.26,38.13,38.49,38.4738.438.9±2.10.460.47-1.29實驗室二RMK011a21.41,21.63,21.49,21.87,21.99,21.5821.421.1±1.31.050.581.42RMK02132.80,33.07,33.59,32.64,33.57,33.623333.2±1.80.880.77-0.60RMH-F11138.08,38.10,38.76,38.86,38.24,39.1239.338.9±2.10.690.771.03實驗室三RMK011a21.37,21.83,21.30,21.45,21.54,21.7221.521.1±1.30.960.51.90RMK02132.86,33.31,33.64,32.98,33.43,33.1833.233.2±1.80.870.780.00RMH-F11138.25,38.63,38.82,38.93,38.77,38.639.338.9±2.10.610.681.03實驗室四RMK011a21.61,21.74,21.20,21.55,21.82,21.6321.621.1±1.31.00.622.37RMK02132.77,33.01,33.58,32.73,33.54,32.7833.133.2±1.81.140.81-0.30RMH-F11139.32,39.03,39.62,39.44,39.07,39.3139.338.9±2.10.570.591.03結(jié)果表明，各實驗室相對標(biāo)準(zhǔn)偏差在0.46%～1.14%之間，極差為0.44%~0.81%，精密度良好。從準(zhǔn)確度來看，相對誤差在-1.29%～2.37%之間，且測定值均落入標(biāo)準(zhǔn)值的不確定度區(qū)間內(nèi)，說明測定結(jié)果可靠，方法的準(zhǔn)確度滿意。實際樣品測定結(jié)果重現(xiàn)性試驗4家實驗室使用本標(biāo)準(zhǔn)方法對統(tǒng)一實際樣品進(jìn)行了檢測，最后使用統(tǒng)計學(xué)原理—格拉布斯檢驗法對結(jié)果進(jìn)行評價，評判最小值或最大值是否離群。表3實際樣品重現(xiàn)性試驗數(shù)據(jù)樣品編號結(jié)果平均值標(biāo)準(zhǔn)偏差相對標(biāo)準(zhǔn)偏差%最小值最大值GminGmax實驗室1實驗室2實驗室3實驗室4240700125.125.825.126.025.50.471.825.126.00.851.06240700223.023.323.023.823.30.380.723.023.80.791.32240700333.734.633.734.834.20.581.533.734.80.861.03240700418.018.517.918.818.30.421.817.918.80.951.19240700530.331.330.331.230.80.551.930.331.30.910.91240700619.020.018.919.419.30.503.218.920.00.801.40240700734.133.934.134.634.20.300.333.934.61.001.33240700821.922.221.922.622.20.330.821.922.60.911.21240700929.129.329.129.329.20.120.429.129.30.830.83240701024.425.724.425.825.10.783.024.425.80.900.90240701131.131.831.132.331.60.591.331.132.30.851.19240701222.622.922.623.422.90.380.822.623.40.791.32240701318.318.418.218.718.40.220.518.218.70.911.36240701423.023.223.123.223.10.100.423.023.21.001.00240701523.524.223.524.323.90.431.723.524.30.930.93240701626.226.826.227.226.60.491.326.227.20.821.22240701735.035.935.035.535.40.441.535.035.90.911216.816.217.516.70.622.116.217.50.811.29240701933.733.833.533.933.70.170.533.533.91.181515.715.416.115.70.311.015.416.10.971.29240702116.617.816.617.117.00.574.116.617.80.701.40240702228.428.928.429.528.80.521.028.429.50.771.35240702325.525.625.526.225.70.340.225.526.20.591.47240702419.119.919.120.019.50.492.419.120.00.821.02240702518.919.718.819.419.20.422.618.819.70.951.19240702629.230.029.229.629.50.381.629.230.00.791.32240702725.325.625.325.425.40.140.725.325.60.711.43240702818.118.618.118.318.30.241.618.118.60.831.25240702932.933.232.933.233.10.170.532.933.21.180.59240703027.127.527.127.827.40.340.827.127.80.881026.125.925.926.00.100.425.926.11.001.00240703233.033.733.033.133.20.341.233.033.70.591.47240703332.131.832.132.532.10.290.531.832.51.031.38240703431.331.631.331.631.50.170.531.331.61.180.59240703533.634.433.634.234.00.411.433.634.40.980.98240703622.123.222.122.722.50.532.822.123.20.751.32240703725.726.225.726.326.00.321.125.726.30.940.94240703815.615.815.616.115.80.240.715.616.10.831.25240703925.826.125.826.126.00.170.725.826.11.180.59240704022.723.222.723.423.00.361.322.723.40.831.11240704119.321.020.220.920.40.794.219.321.01.390.76240704224.824.924.824.724.80.080.224.724.91.251.25240704327.027.427.027.727.30.340.827.027.70.881424.323.424.223.80.492.223.424.30.821.02240704534.635.634.634.834.90.481.734.635.60.621.46240704634.434.934.434.634.60.240.834.434.90.831.25240704730.030.229.930.530.20.260.529.930.51.151124.724.424.824.50.321.224.124.81.250.94240704928.929.028.929.529.10.290.228.929.50.691.38240705017.218.017.217.517.50.382.617.218.00.791.32240705124.324.224.324.724.40.220.224.224.70.911.36240705225.826.625.826.026.10.381.825.826.60.791.32240705334.134.534.135.034.40.430.734.135.00.701.40240705434.034.234.034.834.30.380.334.034.80.791.32240705531.732.031.731.931.80.150.531.732.00.671.33240705630.931.830.931.531.30.451.730.931.80.891.11240705723.523.523.423.623.50.080.223.423.61.251.25240705826.827.426.827.127.00.291.326.827.40.691.38240705921.322.321.322.421.80.612.621.322.40.820.98240706029.730.129.129.829.70.421.729.130.11.430.95240706115.915.515.515.915.70.231.515.515.90.870.87240706219.319.618.919.419.30.291.818.919.61.381.03240706334.835.434.835.135.00.291.034.835.40.691.38240706418.418.518.419.518.70.540.318.419.50.561.48240706518.418.318.318.218.30.080.318.218.41.251.25240706621.822.121.522.422.00.391.421.522.41.281.03240706733.233.433.234.533.60.620.333.234.50.651.45240706834.134.934.135.034.50.491.334.135.00.821.02240706928.128.527.928.228.20.251.127.928.51.201.20240707024.525.024.624.824.70.221.124.525.00.911.36格拉布斯檢驗結(jié)果表明測定結(jié)果中無異常值（當(dāng)n=4，α=0.05時臨界值為1.481，α=0.01時臨界值為1.496），即本法獲得的測定結(jié)果重現(xiàn)性良好。各實驗室實際樣品試驗數(shù)據(jù)表4實驗室一試驗數(shù)據(jù)樣品編號有機(jī)質(zhì)含量（%）測定值1測定值2平均值絕對差值240700125.025.225.10.2240700223.023.023.00.0240700333.633.733.70.1240700417.818.118.00.3240700530.230.330.30.1240700618.919.019.00.1240700733.734.434.10.7240700821.722.121.90.4240700929.029.229.10.2240701024.424.424.40.0240701131.031.231.10.2240701222.522.722.60.2240701318.218.418.30.2240701422.923.123.00.2240701523.323.623.50.3240701626.026.426.20.4240701734.735.335.00.6240701816.116.216.20.1240701933.334.033.70.7240702015.415.515.50.1240702116.416.816.60.4240702228.328.528.40.2240702325.225.825.50.6240702418.919.319.10.4240702518.819.018.90.2240702629.129.229.20.1240702725.125.525.30.4240702817.918.318.10.4240702932.833.032.90.2240703026.927.227.10.3240703125.726.226.00.5240703232.633.333.00.7240703331.832.332.10.5240703430.931.631.30.7240703533.533.733.60.2240703621.922.222.10.3240703725.625.825.70.2240703815.515.715.60.2240703925.626.025.80.4240704022.522.822.70.3240704119.219.419.30.2240704224.525.124.80.6240704326.727.327.00.6240704423.323.523.40.2240704534.434.734.60.3240704634.034.834.40.8240704729.730.330.00.6240704824.024.224.10.2240704928.829.028.90.2240705017.017.417.20.4240705123.924.624.30.7240705225.526.025.80.5240705334.134.134.10.0240705433.934.034.00.1240705531.432.031.70.6240705630.531.330.90.8240705723.223.823.50.6240705826.527.026.80.5240705921.321.321.30.0240706029.330.029.70.7240706115.816.015.90.2240706219.319.319.30.0240706334.435.234.80.8240706418.218.518.40.3240706518.318.518.40.2240706621.622.021.80.4240706733.133.233.20.1240706833.834.334.10.5240706927.828.428.10.6240707024.224.824.50.6表5實驗室二試驗數(shù)據(jù)樣品編號有機(jī)質(zhì)含量（%）測定值1測定值2平均值絕對差值240700125.626.025.80.4240700223.123.523.30.4240700334.434.734.60.3240700418.318.618.50.3240700531.031.631.30.6240700619.820.220.00.4240700733.734.033.90.3240700822.122.222.20.1240700929.329.329.30.0240701025.426.025.70.6240701131.432.231.80.8240701222.822.922.90.1240701318.318.418.40.1240701423.223.223.20.0240701524.024.424.20.4240701626.627.026.80.4240701735.636.235.90.6240701816.716.816.80.1240701933.534.133.80.6240702015.515.915.70.4240702117.618.017.80.4240702228.629.128.90.5240702325.325.925.60.6240702419.819.919.90.1240702519.519.819.70.3240702629.830.130.00.3240702725.625.625.60.0240702818.318.818.60.5240702932.933.533.20.6240703027.327.727.50.4240703125.826.426.10.6240703233.334.033.70.7240703331.831.831.80.0240703431.431.731.60.3240703534.134.634.40.5240703622.923.523.20.6240703725.926.426.20.5240703815.616.015.80.4240703926.026.226.10.2240704022.823.523.20.7240704120.921.121.00.2240704224.625.124.90.5240704327.327.427.40.1240704424.224.424.30.2240704535.335.835.60.5240704634.735.034.90.3240704730.030.330.20.3240704824.524.924.70.4240704928.829.229.00.4240705017.818.118.00.3240705124.124.224.20.1240705226.426.726.60.3240705334.334.634.50.3240705433.934.534.20.6240705531.632.332.00.7240705631.432.231.80.8240705723.323.723.50.4240705827.227.527.40.3240705921.922.622.30.7240706029.830.330.10.5240706115.315.615.50.3240706219.419.819.60.4240706335.335.535.40.2240706418.418.518.50.1240706518.118.418.30.3240706622.022.222.10.2240706733.333.533.40.2240706834.735.034.90.3240706928.428.628.50.2240707024.925.025.00.1表6實驗室三試驗數(shù)據(jù)樣品編號有機(jī)質(zhì)含量（%）測定值1測定值2平均值絕對差值240700125.025.225.10.2240700223.023.023.00.0240700333.633.733.70.1240700417.718.117.90.4240700530.230.330.30.1240700618.819.018.90.2240700733.734.434.10.7240700821.722.121.90.4240700929.029.229.10.2240701024.424.424.40.0240701131.031.231.10.2240701222.522.722.60.2240701317.918.418.20.5240701422.923.223.10.3240701523.323.623.50.3240701626.026.426.20.4240701734.735.335.00.6240701816.116.216.20.1240701933.233.833.50.6240702015.215.615.40.4240702116.416.816.60.4240702228.328.528.40.2240702325.225.825.50.6240702418.919.219.10.3240702518.519.018.80.5240702629.129.229.20.1240702725.125.525.30.4240702817.918.318.10.4240702932.833.032.90.2240703026.927.227.10.3240703125.626.125.90.5240703232.633.333.00.7240703331.832.332.10.5240703430.931.631.30.7240703533.533.733.60.2240703621.922.222.10.3240703725.625.825.70.2240703815.415.715.60.3240703925.626.025.80.4240704022.522.822.70.3240704119.920.420.20.5240704224.525.124.80.6240704326.727.327.00.6240704423.323.523.40.2240704534.434.734.60.3240704634.034.834.40.8240704729.730.129.90.4240704824.124.724.40.6240704928.829.028.90.2240705017.017.417.20.4240705123.924.624.30.7240705225.526.025.80.5240705334.134.134.10.0240705433.934.034.00.1240705531.432.031.70.6240705630.531.330.90.8240705723.123.723.40.6240705826.527.026.80.5240705921.321.321.30.0240706029.328.829.10.5240706115.315.715.50.4240706218.719.118.90.4240706334.435.234.80.8240706418.218.518.40.3240706518.118.418.30.3240706621.221.821.50.6240706733.133.233.20.1240706833.834.334.10.5240706927.628.227.90.6240707024.324.824.60.5表7實驗室四試驗數(shù)據(jù)樣品編號有機(jī)質(zhì)含量（%）測定值1測定值2平均值絕對差值240700125.726.226.00.5240700223.623.923.80.3240700334.535.134.80.6240700418.619.018.80.4240700530.931.431.20.5240700619.119.619.40.5240700734.234.934.60.7240700822.322.822.60.5240700929.229.329.30.1240701025.526.025.80.5240701131.932.632.30.7240701223.123.723.40.6240701318.618.818.70.2240701423.123.223.20.1240701524.024.624.30.6240701626.927.527.20.6240701735.235.735.50.5240701817.317.617.50.3240701933.534.233.90.7240702016.016.216.10.2240702116.917.217.10.3240702229.329.729.50.4240702325.926.426.20.5240702419.820.220.00.4240702519.219.619.40.4240702629.429.829.60.4240702725.225.525.40.3240702818.118.518.3